The research, conducted by a team spanning Algeria and the IHU Méditerranée Infection in Marseille, France, focused on the Béjaïa region of northern Algeria. Between December 2023 and January 2024, the investigators collected 160 bovine and 231 caprine milk samples, a total of 391 specimens, drawn during routine milking from seven farms. The samples were transported at 4 degrees Celsius and shipped to Marseille under import permit ER-02-2024 for analysis. The choice of targets reflected both local and global concerns: the Mycobacterium tuberculosis complex, which includes Mycobacterium bovis, the agent of bovine tuberculosis; Mycobacterium uberis, a recently described species that causes nodular thelitis and tuberculoid scrotitis in livestock; Mycobacterium leprae and Mycobacterium lepromatosis, the two leprosy bacilli, whose animal reservoirs have been documented outside North Africa; and Mycobacterium ulcerans, the cause of Buruli ulcer, which has been reported in domestic animals elsewhere.

The laboratory workflow was designed to maximise sensitivity while guarding against the two classic pitfalls of molecular diagnostics: failed extraction and contamination. Each milk sample was first centrifuged at 3,000 times gravity for 15 minutes to concentrate bacteria and cellular debris into a pellet. A synthetic internal amplification control, designated TIIS, was then added to every pellet before automated DNA extraction on a QIAGEN EZ1 Advanced XL platform. This internal control serves a critical function: if it amplifies in the downstream polymerase chain reaction, it demonstrates that DNA was successfully extracted and that no inhibitors in the milk matrix suppressed the enzymatic reaction. Without such a control, a negative result would be ambiguous, because it could reflect either a true absence of the pathogen or simply a technical failure.

Detection relied on five independent hydrolysis-probe quantitative PCR assays, each targeting a species-specific genetic signature. The RLEP assay targeted M. leprae, the RLPM assay targeted M. lepromatosis, an assay directed at the ESX-1 locus detected M. uberis, a CRISPR-Csm4-based assay identified the M. tuberculosis complex, and a PPE-targeted assay screened for M. ulcerans. Thermocycling consisted of an initial denaturation step at 95 degrees Celsius for two minutes, followed by 45 cycles of 95 degrees Celsius for 15 seconds and 58 degrees Celsius for 60 seconds. A specimen was scored as positive only when a target-specific amplification curve crossed the fluorescence threshold within the 45-cycle run, and only if the corresponding internal control amplified and the no-template water control remained negative. Samples without target-specific amplification were recorded as having undetermined cycle threshold values.

Contamination control received particular attention. Positive control materials were deliberately excluded from routine sample-testing runs to minimise the risk of cross-contamination, a precaution that is especially important when screening for organisms such as M. leprae, where even trace carryover of amplifiable DNA could produce a false positive. The external M. leprae positive control was tested separately, and additional validation assays were performed to confirm the specificity of each primer-probe set and the overall performance of the qPCR platform. The published analytical sensitivities of the RLEP and RLPM assays, along with the oligonucleotide sequences and cycle threshold interpretation criteria, were documented in the supplementary materials accompanying the paper, allowing other laboratories to reproduce or compare the methodology.

The results were unambiguous. All TIIS internal amplification controls amplified successfully, confirming that DNA extraction worked in every one of the 391 samples and that no qPCR inhibition was detectable. All no-template water controls remained negative, providing no evidence of reagent contamination. Yet no target-specific amplification was observed in any sample for any of the five mycobacterial targets. In other words, across every bovine and caprine milk specimen tested, the investigators could not detect DNA from the tuberculosis complex, from either leprosy bacillus, from M. uberis, or from M. ulcerans.

With zero detections, the study turned to statistics to quantify the strength of that negative finding. Using exact one-sided 95 percent confidence limits, the researchers calculated that the upper bound for the proportion of qPCR-positive samples was 1.85 percent in bovine milk, 1.29 percent in caprine milk, and 0.76 percent overall. These figures are worth understanding correctly: they do not mean that 1.85 percent of samples were contaminated, but rather that, given 391 samples with no detections, the true proportion of positive samples is statistically very unlikely to exceed those thresholds. The limits describe detectable DNA in the milk itself, not the prevalence of infection in the source animals, a distinction that matters greatly for interpreting the public-health significance of the work.

The authors are careful to place these findings in context. The absence of M. tuberculosis complex DNA is reassuring, but it should not be read as proof that bovine tuberculosis is absent from the region. Mycobacterial shedding in milk can be intermittent, meaning that a single point-in-time sample may miss an animal that sheds bacteria at other moments. The survey did not specifically select animals with mastitis, tuberculosis-compatible lesions, or known positive herd status, which are precisely the animals most likely to shed pathogens into milk. Sampling was also restricted to seven farms in a single region, so the results cannot be extrapolated to all of Algeria. Bacterial loads below the analytical sensitivity of the assays remain possible, and qPCR alone cannot establish whether any detected organism would be viable; culture and herd-level testing remain essential complements. Published milk studies show marked variation in M. bovis detection depending on herd infection status, specimen type, and analytical method, with an international meta-analysis reporting a pooled prevalence of around 5 percent in individual samples, a figure that underscores how heterogeneous the global picture is.

The same caution applies to the other four targets. Non-detection of M. leprae, M. lepromatosis, M. uberis, and M. ulcerans in milk does not exclude their presence in other tissues, other hosts, or environmental compartments. Red squirrels in the British Isles, for example, have been found to harbour leprosy bacilli, and M. ulcerans infection has been documented in domestic animals in West Africa, demonstrating that these organisms can occupy unexpected ecological niches. Nevertheless, the absence of target-specific amplification across 391 internally controlled extracts provides a valuable regional baseline for northern Algeria, a baseline that simply did not exist before.

The study’s broader significance lies in its methodology as much as its results. By combining rigorous internal amplification controls, strict contamination management, and statistically framed interpretation of zero detections, the work offers a template for how molecular surveillance of the dairy supply should be conducted in regions where raw milk consumption is common and veterinary diagnostic infrastructure may be limited. The authors conclude that broader longitudinal studies, combining repeated milk sampling with culture, tissue analysis, and herd-level diagnostics, are required to define the occurrence and public-health relevance of pathogenic mycobacteria in Algerian dairy systems. Until such studies are completed, the new findings stand as a carefully qualified but genuinely encouraging data point: at the time of sampling, no molecular evidence indicated that milk from the surveyed herds carried detectable DNA from any of five dangerous mycobacterial species.

Subject of Research: Molecular detection of zoonotic pathogenic mycobacteria in bovine and caprine milk in northern Algeria

Article Title: Absence of molecular detection of zoonotic mycobacteria in bovine and caprine milk in northern Algeria.

Article References: Souguel, S., Ndiaye, A., Boualam, M., Grine, G., Agag, S., Drancourt, M., & Tazerart, F. (2026). Absence of molecular detection of zoonotic mycobacteria in bovine and caprine milk in northern Algeria.. New Microbes and New Infections, Article 101866. https://doi.org/10.1016/j.nmni.2026.101866

Image Credits: AI Generated

DOI: 10.1016/j.nmni.2026.101866

Keywords: Mycobacterium bovis, Mycobacterium leprae, Mycobacterium ulcerans, Mycobacterium uberis, bovine tuberculosis, raw milk, qPCR, Algeria, food safety, zoonoses, dairy surveillance, molecular diagnostics

Toxoplasma gondii is one of the most successful parasites on Earth, capable of infecting virtually all warm-blooded animals, yet most human infections go entirely unnoticed. In a healthy adult, the immune system usually contains the parasite, which then persists in a dormant tissue-cyst form, primarily in muscle and brain tissue. The danger arises when a woman acquires her first infection shortly before or during pregnancy. At that point, before protective antibodies have fully developed, the parasite can spread through the bloodstream, invade the placenta, and infect the fetus. Congenital toxoplasmosis can cause miscarriage, stillbirth, hydrocephalus, chorioretinitis that threatens vision, intracranial calcifications, seizures, and long-term neurodevelopmental impairment. Because primary infection in the mother is typically asymptomatic or produces only mild, flu-like symptoms, the only practical way to identify women at risk is through serological testing, which is precisely what has been missing in much of sub-Saharan Africa.

The research team, led by Yared Mulu Gelaw of Bahir Dar University together with collaborators including Jean-Pierre Gangneux and Florence Robert-Gangneux of Rennes, France, set out to fill that gap using a tool designed for exactly this kind of resource-limited setting. The Toxoplasma ICT IgG-IgM test manufactured by LD Bio is a lateral-flow immunochromatographic assay, the same technological family as the rapid tests familiar from malaria and HIV screening. A small blood sample, applied to the test cassette, migrates along a membrane carrying immobilized antigens; antibodies against Toxoplasma, if present, are captured and visualized as colored lines within minutes. No laboratory infrastructure, electricity, cold chain, or specialized technician is required. The trade-off is that the combined IgG-IgM format indicates whether a woman has ever been infected, but does not by itself distinguish a recent, potentially dangerous primary infection from long-standing, dormant immunity, a limitation the authors acknowledge explicitly.

Study participants were recruited using systematic random sampling among women presenting at less than 20 weeks of gestation, with the average participant enrolled at roughly 14 weeks of pregnancy. The cohort was predominantly urban, with 85.2 percent of women living in city areas, and had a mean age of 26.8 years. The median monthly household income was 5,000 Ethiopian Birr, a figure that situates most families well within the economic constraints that shape diet, hygiene, and access to care. Alongside the blood sample, each woman completed a structured questionnaire covering sociodemographic characteristics, obstetric history, and the dietary and hygienic practices long associated with Toxoplasma transmission, from handling raw meat to consuming unpasteurized dairy. Statistical analysis, performed with binary logistic regression at both bivariable and multivariable levels, then identified which factors independently predicted seropositivity.

The headline number, 75.8 percent seroprevalence, means that only about one in four pregnant women in the cohort lacked antibodies and therefore remained fully susceptible to a primary infection during pregnancy. Seroprevalence rose steadily with both age and parity, an expected pattern for a parasite acquired cumulatively over a lifetime of exposure: each additional year and each additional pregnancy increases the cumulative probability of having encountered Toxoplasma. Notably, the classic socioeconomic gradients often reported elsewhere did not appear here. Educational level, monthly income, occupation, urban versus rural residence, and self-reported hygienic behaviors showed no significant association with seropositivity, suggesting that in this setting the parasite is so widely distributed in the food and environment that wealth and education offer little protection.

What did matter were specific dietary exposures. After adjustment for other variables, women who reported eating undercooked meat had roughly 29 percent higher odds of being seropositive, while those who drank raw milk had 82 percent higher odds, the strongest single risk factor identified in the study. Each additional year of age raised the odds by about 9 percent, and each prior pregnancy by about 33 percent. These findings map cleanly onto the parasite’s known biology. Tissue cysts harboring slowly replicating bradyzoites survive in undercooked beef, lamb, and goat meat, and ingestion of these cysts is one of the two principal routes of human infection worldwide. Raw or unpasteurized milk, particularly from goats, has been implicated in outbreaks of toxoplasmosis and can carry the parasite when animals are actively infected. In a culinary culture where raw meat dishes are traditional and home consumption of unpasteurized dairy is common, these routes of transmission appear to dominate.

The absence of an association with cat ownership or contact deserves attention, because the domestic cat is the definitive host of Toxoplasma and the source of the environmentally resistant oocysts that contaminate soil, water, and vegetables. In this study, hygienic factors generally failed to predict seropositivity, which the authors interpret as evidence that foodborne transmission, rather than direct contact with cats or contaminated soil, is the dominant driver of infection in Bahir Dar. This has practical consequences for prevention. While advising pregnant women to avoid cleaning litter trays remains sensible wherever cats are kept, the far higher-yield interventions here are culinary: cooking meat thoroughly, washing hands and utensils after handling raw meat, and boiling or pasteurizing milk before drinking it.

The choice of screening technology is central to the study’s significance. Conventional serology, whether the Sabin-Feldman dye test, enzyme-linked immunosorbent assays, or chemiluminescence, requires equipped laboratories, trained staff, and reliable supply chains that many antenatal clinics in low-income countries cannot sustain. As a result, Toxoplasma screening during pregnancy is routine in France and several other European countries but essentially nonexistent across most of Africa, leaving the true burden of congenital infection unmeasured. A lateral-flow test that can be performed at the point of care during a first antenatal visit changes that calculus. The authors argue that the ease of use of the Toxoplasma ICT test makes serological screening of pregnant women feasible directly within antenatal care facilities, without referral to distant laboratories. A positive result identifies a woman who has been exposed; a negative result identifies the smaller but clinically crucial group of susceptible women who would benefit most from targeted prevention counseling.

The study does carry limitations that temper interpretation. Because the ICT format reports any Toxoplasma antibody without separately distinguishing IgG from IgM, the 75.8 percent figure represents lifetime exposure rather than the rate of active or recent infection, so it cannot directly estimate how many pregnancies in the cohort were actually threatened by congenital transmission. The cross-sectional design captures a single moment in pregnancy rather than following women forward to birth outcomes, and the reliance on self-reported dietary habits introduces the possibility of recall bias. Nevertheless, as the first application of rapid immunochromatographic screening for Toxoplasma in pregnant women in Ethiopia, the study establishes both a baseline burden estimate and a proof of concept for a screening strategy that could be replicated in other high-burden, low-resource settings.

The public health implications are considerable. With three-quarters of women already immune, universal primary prevention messaging would reach many who no longer need it, while the quarter who remain susceptible face a real and quantifiable risk from two modifiable habits: eating undercooked meat and drinking raw milk. The authors conclude that efforts should focus on raising women’s awareness of these risk factors, particularly the consumption of raw meat and raw milk, and that the operational simplicity of the ICT test opens the door to integrating Toxoplasma serology into routine antenatal care. For a parasite that has historically been invisible to the health systems most exposed to it, a fifteen-minute test at the first prenatal visit may be the beginning of making congenital toxoplasmosis a measurable, and ultimately preventable, problem in Ethiopia.

Subject of Research: Seroprevalence and risk factors of Toxoplasma gondii infection among pregnant women in Bahir Dar, Ethiopia, using rapid immunochromatographic testing

Article Title: First use of rapid ICT screening for Toxoplasma in pregnant women in Ethiopia: A multicenter study in Bahir Dar, Ethiopia

Article References: First use of rapid ICT screening for Toxoplasma in pregnant women in Ethiopia: A multicenter study in Bahir Dar, Ethiopia. (n.d.). https://doi.org/10.1371/journal.pntd.0014616

Image Credits: AI Generated

DOI: 10.1371/journal.pntd.0014616

Keywords: Toxoplasma gondii, toxoplasmosis, pregnancy, seroprevalence, immunochromatographic test, Ethiopia, Bahir Dar, congenital infection, antenatal care, foodborne transmission, raw milk, undercooked meat

The Academy did not stop at advising families to avoid raw dairy. It renewed its call for a ban on the sale and distribution of raw milk and raw milk products, including raw cheeses, arguing that their consumption increases the risk of life-threatening infections. The policy statement also directly confronts one of the most persistent marketing claims surrounding raw milk: that it offers superior health benefits compared with pasteurized products. According to the Academy, those claims are not supported by scientific evidence. Pasteurization, a process of heating and then cooling milk that has been in use for more than a century, dramatically reduces the risk of infection without stripping away the nutritional value that families rely on from dairy.

The numbers behind the Academy’s concern are striking. Lead author Adam J. Ratner, MD, MPH, FAAP, noted that nearly half of illnesses caused by raw dairy consumption occur in people under the age of 20, and that a significant share of those cases are in children under 5. These illnesses, he emphasized, can be severe and can lead to life-threatening complications. The vulnerability of young children is not incidental: their immune systems are still developing, their body weight is small relative to the dose of pathogen they may ingest, and complications such as severe dehydration from diarrheal illness or kidney failure from certain strains of E. coli can escalate quickly in pediatric patients.

Unpasteurized milk is a well-documented carrier of some of the most dangerous foodborne pathogens known to medicine. The policy statement lists Listeria, E. coli, Salmonella, Campylobacter, and Brucella among the serious organisms transmitted through raw dairy. Each of these bacteria can cause hospitalization, life-threatening illness, miscarriage, or death, and the risks are concentrated in young children, pregnant people, and individuals with weakened immune systems. Listeria monocytogenes is particularly formidable because it can grow even at refrigerator temperatures, meaning contaminated dairy stored properly in a home kitchen can still become more dangerous over time. Salmonella and Campylobacter are among the most common causes of bacterial gastroenteritis worldwide, while Shiga toxin-producing E. coli can trigger hemolytic uremic syndrome, a condition that destroys red blood cells and can cause kidney failure in children.

Pregnant people face especially high stakes from foodborne infection. The policy statement notes that the incidence of listeriosis is estimated to be 12 to 14 times higher during pregnancy than in the general population, a reflection of the immune changes that pregnancy induces. Listeria infection during pregnancy can result in miscarriage, stillbirth, premature delivery, or severe illness in newborns, outcomes that make even a low probability of contamination unacceptable from a public health standpoint. Because Listeria can cross the placenta, a mother may experience mild or even unnoticed symptoms while the fetus suffers devastating consequences. This asymmetry between maternal illness and fetal harm is a central reason obstetric and pediatric guidelines consistently single out unpasteurized dairy as a food to avoid entirely during pregnancy.

The most consequential update in the new statement concerns H5N1, the highly pathogenic avian influenza virus that has swept through poultry populations globally and, beginning with the 2024 United States dairy cattle outbreak, demonstrated an ability to infect cows. The Academy highlights emerging evidence that H5N1 may represent a new and potentially serious risk associated with raw milk. Research indicates the virus can be transmitted from infected dairy cattle into milk, where it can reach high concentrations and remain detectable in refrigerated raw milk for up to five weeks. That persistence is unusual and troubling: a virus surviving for more than a month in a chilled, nutrient-rich medium has ample opportunity to reach consumers, especially in distribution chains that lack pathogen testing.

During the 2024 U.S. dairy outbreak, infectious H5N1 virus was detected in nearly one-quarter of raw milk samples in affected areas. To date, there are no confirmed human cases of H5N1 infection resulting from the consumption of raw milk, and the Academy is careful to state this. Nevertheless, it characterizes the virus as a credible, emerging threat. The distinction between documented transmission and credible risk is important in virology: influenza viruses are capable of crossing species barriers, and the mammary gland infections observed in dairy cattle established a novel route by which a respiratory pathogen of birds could contaminate a staple food. Pasteurization, which inactivates influenza viruses effectively, closes that route for conventional dairy, but no such barrier exists for raw products.

The regulatory landscape in the United States remains fragmented. Despite the well-documented health risks, the sale and distribution of raw milk products remain legal in at least 27 states. Raw milk is defined as milk obtained from cows, goats, or sheep that has not undergone pasteurization, the heating process designed to eliminate harmful bacteria and other pathogens. Federal law prohibits the interstate sale of raw milk for human consumption, but intrastate sales fall under state jurisdiction, producing a patchwork in which a family’s exposure to raw dairy risk depends largely on geography. The Academy’s renewed call for a ban on sale and distribution is aimed squarely at this patchwork, arguing that voluntary warnings have not eliminated a preventable source of severe illness.

The scientific case for pasteurization rests on both microbiology and nutrition. The process typically involves heating milk to a temperature sufficient to inactivate vegetative bacterial pathogens and enveloped viruses, followed by rapid cooling to slow the growth of any surviving organisms. Decades of comparative studies have found no meaningful nutritional deficit in pasteurized milk relative to raw milk; the proteins, calcium, and vitamins that make dairy a dietary staple survive the treatment essentially intact. What pasteurization removes is the microbial load, including organisms that may be present even in milk from healthy-appearing animals, since udder infections and fecal contamination during milking can introduce pathogens without any visible sign. Co-author Mark R. Corkins, MD, FAAP, addressed the perception gap directly, saying that parents may choose raw milk because they have heard it is healthier or more natural, but that the scientific evidence tells a different story. Pasteurized dairy products, he said, provide the same essential nutrients without exposing children and families to preventable infections from dangerous bacteria and viruses, and for infants, children, and pregnant people they are clearly the safest choice.

The policy statement was developed through the Academy’s standard process, in which statements written by medical experts reflect the latest available evidence and undergo several rounds of peer review before approval by the AAP Board of Directors and publication in Pediatrics. It will be featured during a presentation on October 5 at the AAP 2026 National Conference and Exhibition in San Diego, where Dr. Ratner is scheduled to discuss the policy during a Meet the Red Book session at the San Diego Convention Center. For families navigating conflicting claims about raw dairy, the Academy has also published a consumer-facing resource, “Raw Milk: What Parents Need to Know About the Risk,” through its HealthyChildren.org platform. The core message of the updated guidance is unambiguous: whatever the appeal of raw milk on the shelf, the pathogens it can carry, from Listeria and E. coli to a potentially pandemic-capable influenza virus, are preventable hazards, and pasteurization remains one of the most effective and time-tested public health interventions in the food supply.

Subject of Research: Health risks of unpasteurized (raw) milk and dairy products for children and pregnant people, including emerging H5N1 avian influenza contamination

Article Title: American Academy of Pediatrics warns of dangers in consuming raw milk, dairy products

Article References: American Academy of Pediatrics warns of dangers in consuming raw milk, dairy products. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: raw milk, pasteurization, American Academy of Pediatrics, H5N1 avian influenza, foodborne illness, Listeria, E. coli, Salmonella, pregnancy, children's health, dairy cattle, public health policy

Raw milk accounted for nearly all of the contamination. Nine of the 170 raw milk samples drawn from dairy cooperatives and collection centres tested positive, a prevalence of 5.29 percent, while a single positive emerged from the 60 samples taken from milking apparatus and transit containers. Strikingly, none of the 90 pasteurised milk samples and none of the 50 worker-related swabs harboured the organism. Eight of the ten raw milk collection centres surveyed showed at least some contamination, with the highest rates reaching 10 percent of samples at individual cooperatives. The pattern is unambiguous: the early, unprocessed stages of the milk chain are where L. monocytogenes persists, and the industrial treatments applied downstream are doing their job.

The complete absence of the pathogen from pasteurised milk is a direct endorsement of the high-temperature, short-time protocol used by the commercial dairies in the region, which heat milk to between 72 and 75 degrees Celsius for 15 seconds before packaging. L. monocytogenes is a non-spore-forming bacterium and is highly vulnerable to these time-temperature combinations, provided that strict hygiene is maintained after treatment to prevent recontamination. The finding matters because listeriosis, the disease the organism causes, carries hospitalisation and mortality rates that are exceptionally high among infants, the elderly, pregnant women, and immunocompromised patients. Unlike many foodborne infections that produce unpleasant but self-limiting illness, listeriosis can invade the bloodstream and central nervous system, making every point of control in the dairy chain a matter of clinical consequence.

What elevates the study beyond a routine prevalence survey is the molecular characterisation of the recovered isolates. Using polymerase chain reaction, the team screened the bacteria for five major virulence genes that govern the organism’s ability to invade and survive inside human cells. Every one of the ten isolates carried prfA, the master transcriptional regulator that switches on Listeria Pathogenicity Island 1, along with inlA, an internalin essential for breaching the intestinal barrier, and iap, a marker associated with invasion and virulence. The gene inlB, which works with inlA to drive uptake into host cells, was present in 90 percent of isolates, and hlyA, which encodes listeriolysin O, the pore-forming toxin that lets the bacterium escape the phagosome and spread cell to cell, was found in 90 percent as well. In practical terms, the strains circulating in Yazd’s raw milk carry the full genetic toolkit for invasive human disease.

One isolate lacked hlyA entirely, a detail with real diagnostic implications. Strains missing the gene for listeriolysin O are considered atypical and often non-haemolytic, meaning they fail the blood-agar tests that many laboratories rely on for routine identification. Such organisms can slip through phenotype-based screening undetected, yet they may possess alternative invasion mechanisms or acquire virulence factors through horizontal gene transfer. Their presence in the food supply is a recognised challenge for public health monitoring, because the diagnostic net designed to catch L. monocytogenes has holes exactly where these variants swim.

The antimicrobial resistance picture is more nuanced, and in some respects reassuring. The isolates showed the expected intrinsic resistance to nalidixic acid, penicillin G, ceftazidime, ceftriaxone, and cefepime, a pattern long documented in this species and the reason cephalosporins are never used to treat listeriosis. More encouragingly, all ten strains were fully susceptible to gentamicin, amikacin, levofloxacin, ciprofloxacin, vancomycin, chloramphenicol, trimethoprim-sulfamethoxazole, ampicillin-sulbactam, and erythromycin, the workhorses of clinical therapy. Resistance to tetracycline appeared in 30 percent of isolates, and imipenem showed a split profile, with half the isolates resistant and half intermediate. Twenty percent of isolates exceeded the multiple antibiotic resistance index threshold of 0.2, a value interpreted as a signature of environments with heavy antibiotic exposure, and the highest indices belonged to strains resistant to imipenem, clindamycin, and tetracycline simultaneously.

The genotyping of resistance determinants uncovered a finding that may prove the most strategically important in the entire study: several resistance genes were present in isolates that remained phenotypically susceptible. The lincosamide resistance genes lnuA and lnuB were detected in 90 and 80 percent of isolates respectively, the macrolide-lincosamide-streptogramin genes ermA and ermB in 40 and 30 percent, the aminoglycoside gene aadB in 30 percent, and the tetracycline genes tetA and tetM, which mediate efflux and ribosomal protection, in 30 percent each. Yet clindamycin susceptibility remained at 90 percent and erythromycin at 100 percent. This silent carriage of resistance genes, likely due to non-functional promoters, regulatory mutations, or the absence of environmental triggers needed for expression under laboratory conditions, means these strains hold the genetic blueprint to flip to a resistant phenotype through gene activation or horizontal transfer. Phenotypic testing alone would miss the threat entirely, which is why the authors argue that molecular surveillance must run alongside conventional susceptibility testing.

The coexistence of a complete virulence gene complement with a broad array of resistance determinants in the same small set of isolates paints a picture of strains that are both capable of causing severe disease and equipped to survive therapeutic pressure. The researchers contextualise their findings against international data: prevalence figures of 18.46 percent in South African milk samples, 28.26 percent in milk from aborted cows in Iraq, and 2.48 percent in bovine milk in Southwest China all confirm that milk is a substantial and recurring reservoir for this pathogen worldwide. Comparable genomic surveys in dairy products across India and China have likewise documented the ubiquitous presence of prfA, inlA, inlB, iap, and hlyA alongside multidrug resistance, suggesting that the Yazd findings reflect a global pattern rather than a local anomaly.

The study is not without limits, and the authors acknowledge them candidly. The low isolation rate yielded only ten confirmed strains, a sample too small to generalise precise resistance percentages across the entire province. Nevertheless, the detailed molecular characterisation provides a baseline for future large-scale monitoring in a region where such data have been scarce. The contamination of 80 percent of raw milk collection points points to hygiene failures at the earliest stage of the chain, where faecal contamination during milking, mastitic glands, and environmental reservoirs such as silage, soil, and water all offer the bacterium entry routes. The single positive from milking equipment reinforces the well-established capacity of L. monocytogenes to form resilient biofilms on food-contact surfaces, which complicates sanitation in processing facilities.

The practical message for consumers and regulators alike is clear. Pasteurisation works, and the zero detection rate in commercial pasteurised milk demonstrates that the technology, properly applied, eliminates the pathogen from the final product. The risk concentrates in raw milk, which is sometimes consumed directly or used in traditional dairy products, exposing vulnerable populations to strains that are simultaneously highly virulent and increasingly drug-resistant. The authors call for continuous monitoring of L. monocytogenes, rigorous hygiene in raw milk production, judicious antibiotic use in veterinary medicine, and routine molecular surveillance to prevent the circulation of pathogenic and resistant strains. As antimicrobial resistance continues its global advance, studies like this one demonstrate that the front line of food safety runs directly through the dairy farm, and that the tools to track the threat, from PCR screens for virulence genes to resistance indices, are already in hand.

Subject of Research: Prevalence, virulence genes, and antimicrobial resistance of Listeria monocytogenes in the dairy supply chain

Article Title: Molecular Characterisation and Antimicrobial Resistance Patterns of Listeria monocytogenes From Dairy Sources

Article References: Heidari, M. R., Shakerian, A., Chaleshtori, R. S., & Rahimi, E. (2026). Molecular Characterisation and Antimicrobial Resistance Patterns of Listeria monocytogenes From Dairy Sources. Veterinary Medicine and Science, 12(6), Article e71265. https://doi.org/10.1002/vms3.71265

Image Credits: AI Generated

DOI: 10.1002/vms3.71265

Keywords: Listeria monocytogenes, raw milk, foodborne disease, antimicrobial resistance, virulence genes, pasteurisation, dairy safety, PCR, MAR index, listeriosis, Iran, public health

The story of Khiki cheese begins with Iran’s vast flocks of sheep and goats, animals far better suited to the country’s arid and mountainous landscapes than cattle. According to figures cited in the review from the Iranian Ministry of Agriculture, the country held roughly 49.4 million sheep and 16.8 million goats in 2023, and nomadic communities breed the majority of them. These herders produce more than 460,000 tons of milk annually, and cheese made from that milk provides an essential source of income and trade. Khiki cheese varieties alone exceed 2,500 tons per year, produced across at least ten provinces including Gilan, North Khorasan, Semnan, West Azarbayjan, Kurdistan, Lorestan, Khuzestan, Fars, and Kerman.

What makes Khiki cheese genuinely distinctive is its ripening vessel. The practice of maturing cheese inside animal skin bags is shared by only a handful of traditions worldwide, including Tulum cheese in Turkey, Darfiyeh in Lebanon, Motal in Azerbaijan, Mišina in Croatia, Mjeh in Bosnia and Herzegovina and Montenegro, and Bouhezza in eastern Algeria. Preparing the bag is an art in itself: the skin is carefully peeled without tearing, scraped clean of flesh, washed, soaked in salt for 24 hours, and sun-dried for 20 to 25 days. All openings except the neck are sewn shut, and the interior is coated with salt and diluted yogurt before the cheese is introduced. Producers generally prefer goatskin because it is stronger than sheepskin.

The production process relies entirely on raw, unpasteurized milk from sheep, goats, or a mixture of the two, with no industrial starter cultures. Fresh milk is filtered, rennet is added, and after about an hour the coagulated curd is drained in cotton cloth, salted to accelerate dehydration, and submerged in 10 to 12 percent brine for 20 to 45 days. The hardened curd is then cut into small cubes and packed into the salted skin bag, which is sealed and stored at roughly 6 to 12 degrees Celsius for three to nine months. Regional variations abound: Kordi cheese from North Khorasan is periodically topped up with whey, dough, or milk to prevent moisture loss, while Aftar cheese from Semnan is ripened in a cave and brined in a saturated 22 percent salt solution. In Lorestan, the bag itself is coated with kashk, a dehydrated yogurt product, before filling.

Because every batch starts with raw milk and a hand-prepared skin, the chemistry of the final cheese varies enormously. Reported pH values span from 4.46 to 6.74, titratable acidity from 0.86 to 13.52 percent lactic acid, moisture from 12.14 to 40.92 percent, fat from 3.8 to 28 percent, and protein from 4.57 to 27.79 percent. The review’s authors caution that this variability is so broad that Khiki cheese cannot be uniformly classified as a full-fat semi-hard cheese under the Codex Alimentarius standard, since the fat-in-dry-matter and moisture-on-a-fat-free-basis values required for that designation have not been consistently measured across varieties.

Ripening inside the permeable skin bag drives a cascade of biochemical transformations. Proteolytic enzymes from rennet, the raw milk, and the bag’s own microflora progressively break down casein into peptides and free amino acids, a process tracked by the water-soluble nitrogen index, which can reach over 61 percent of total nitrogen. Lipolysis releases free fatty acids, particularly short-chain ones that give the cheese its sharp, buttery aroma, and these fatty acids serve as precursors for methyl ketones and esters that deepen the flavor. Meanwhile, salt diffusing inward from the brine tightens the protein matrix through enhanced hydrophobic interactions, and scanning electron microscopy studies show the casein network becoming denser and more compact during the first month, with pore size and roughness increasing as ripening advances.

The microbial ecology of Khiki cheese is where the story becomes truly compelling. Lactic acid bacteria dominate, with counts between 10^3 and 10^6 colony-forming units per gram, and the dominant genera are Lactobacillus, followed by Enterococcus and Pediococcus. Species such as Lactobacillus plantarum, L. casei, L. paracasei, L. brevis, and L. acidophilus have all been isolated, alongside Enterococcus faecium and E. durans. These organisms do more than sour the cheese: they produce organic acids, hydrogen peroxide, and bacteriocins that suppress pathogens. Studies show that coliforms and Staphylococcus aureus detected early in ripening are typically eliminated by the second month, and Salmonella has never been detected in ripened Khiki cheese across multiple investigations.

Food safety remains the central challenge. Because the cheese is made from raw milk under variable hygienic conditions, pathogenic contamination is a real risk, and some E. coli strains isolated from Khiki cheese have carried multiple virulence genes. Pasteurization would eliminate these hazards, but it also destroys the wild lactic acid bacteria responsible for the cheese’s prized flavor and texture; sensory studies consistently show that raw-milk Khiki cheese outperforms its pasteurized counterpart. The solution proposed by researchers is to develop starter and adjunct cultures from the cheese’s own native strains, allowing safe industrial production from pasteurized milk without sacrificing authenticity.

Remarkably, the bacteria of Khiki cheese are proving useful far beyond the dairy case. Strains isolated from the cheese have been deployed as starter cultures for fermented sausages, as anti-yeast agents in the traditional yogurt drink doogh, and as postbiotic coatings that extend the refrigerated shelf life of beef. Even more striking are the probiotic findings: Lactobacillus plantarum strains from Khiki cheese survived simulated gastric conditions, reduced blood glucose and oxidative stress in diabetic rats, and inhibited Listeria monocytogenes and Salmonella. A Lacticaseibacillus casei strain from the cheese showed antimicrobial activity against multiple foodborne pathogens and even cytotoxic effects against cancer cell lines in vitro, while Lactobacillus brevis M3R3 displayed antioxidant and cholesterol-removal properties with a clean safety profile. The authors argue that documenting and standardizing these ancient techniques, classifying varieties by milk type, ripening duration, and compositional indices, could carry a nomadic heritage food into industrial production while preserving the microbial treasures hidden inside its humble skin bags.

Subject of Research: Traditional production, microbiota, and physicochemical properties of Iranian Khiki cheese ripened in animal skin bags

Article Title: Production process, microbiota, and physicochemical composition of traditional cheese products: A case study of Khiki cheese

Article References: Fallah, A. A., Sarmast, E., Jafari, T., Ghasemi, M., & Mousavi Khaneghah, A. (2026). Production process, microbiota, and physicochemical composition of traditional cheese products: A case study of Khiki cheese. Journal of Agriculture and Food Research, 31, Article 103245. https://doi.org/10.1016/j.jafr.2026.103245

Image Credits: AI Generated

DOI: 10.1016/j.jafr.2026.103245

Keywords: Khiki cheese, traditional cheese, Iran, goatskin bag, lactic acid bacteria, raw milk, probiotics, cheese ripening, food safety, Lactobacillus plantarum, dairy microbiology, fermented foods

The chemicals in question come from the vast world of technical rubber—tires, hoses, seals, gaskets, and tubing. Every year, an estimated six million tons of tire and road wear particles are released into the environment worldwide as tires grind against pavement. These particles carry a cocktail of additives: vulcanization accelerators that make rubber cure properly, antioxidants and antiozonants that protect it from heat, oxygen, and cracking, and plasticizers that keep it flexible. As tires degrade on the road, these compounds spread through atmospheric deposition, road runoff, and even biosolid fertilizers applied to farmland, embedding themselves in the soils where food is grown and where livestock graze.

Some of these compounds have already earned a troubling reputation. The tire antioxidant 6-PPD and its oxidation product 6-PPDQ became infamous after scientists discovered that 6-PPDQ washes off roads and kills coho salmon in urban streams within hours of exposure. Subsequent work in mice showed that oral exposure to both chemicals caused dose-dependent accumulation in the liver, elevated liver weight, increased triglycerides, and disruptions in glycolipid metabolism, immune signaling, and glutathione pathways. Another rubber additive, the vulcanization accelerator 1,3-diphenylguanidine, or DPG—produced or imported into the European Economic Area at rates of 10,000 to 100,000 tons per year—has been linked in animal studies to reproductive abnormalities, including altered sperm morphology and reduced fertility, and more recently to genotoxic effects in laboratory bioassays.

Until now, however, almost nothing was known about whether these compounds reach milk. Earlier research had shown that tire-derived chemicals such as benzothiazoles, 6-PPD, and 6-PPDQ can be taken up and metabolized by edible plants like lettuce and carrots, with a compound’s lipophilicity strongly influencing how readily it moves through plant tissues. A recent cross-country survey also found p-phenylenediamines and their quinone derivatives in chicken eggs from thirteen countries across four continents, at concentrations reaching thousands of nanograms per kilogram of egg yolk. Milk, consumed in enormous quantities worldwide and produced on farms that often sit beside busy roads and rely heavily on rubber equipment, represented an obvious but unexamined gap in the picture of dietary exposure.

To close that gap, a team led by Florian Breider and Beat J. Brüschweiler collected seventeen raw cow milk samples from sixteen Swiss farms spanning a range of environments: three alpine farms far from major traffic, three farms near highways carrying roughly 50,000 to 150,000 vehicles per day, four farms near departmental roads with 3,000 to 30,000 vehicles daily, and six farms near country roads with only 500 to 5,000 vehicles. Samples were drawn directly from the milk tanks connected to the milking machines and analyzed using liquid chromatography coupled with tandem mass spectrometry, a sensitive technique capable of detecting trace organic compounds in complex matrices. Deuterated internal standards, matrix-matched calibration, procedural blanks, and recovery corrections were applied throughout, though the authors note that the complexity of milk makes the reported concentrations best regarded as semi-quantitative.

The results revealed that seven of the seventeen samples—41 percent—contained at least one rubber-related compound above the limit of quantification. Four compounds were detected: the benzothiazole vulcanization accelerator S-BTH, the guanidine accelerator DPG, the antioxidant 6-PPD, and its oxidation product 6-PPDQ. DPG appeared in 23 percent of samples at concentrations ranging from 38.8 to 223.3 nanograms per liter, with a median of 68.0. 6-PPD was found in two samples at 71.4 to 99.1 nanograms per liter, and 6-PPDQ appeared once at 75.6 nanograms per liter. S-BTH showed up in a single sample at a striking 26,258.5 nanograms per liter—an apparent outlier that the researchers suggest could reflect localized contamination or release from a specific rubber component, though more sampling would be needed to say for certain.

Intriguingly, none of the target compounds were detected in milk from the three alpine farms located away from major road traffic, while detections occurred at farms near country, departmental, and highway roads. That pattern is compatible with reduced environmental exposure to road-related emissions at high-altitude sites, but the study found no clear relationship between traffic intensity and either detection frequency or concentration—several positive samples in fact came from farms along the quietest roads. With a limited number of farms in each traffic category, and with differences in feeding practices, husbandry conditions, and milking equipment potentially confounding the comparison, the authors are careful not to attribute the contamination solely to road traffic. Determining the true contribution of traffic emissions will require larger studies that also measure these chemicals in air, soil, and feed.

That caution is reinforced by the study’s second, perhaps more surprising, finding. When the researchers analyzed eight rubber components taken directly from dairy production systems—teatcup liners, elbow connectors, rubber sleeves, tubing, connectors, and plugs, all of which touch milk during milking, transfer, or storage—they found fourteen rubber-related chemicals in nearly every component. Total bulk concentrations ranged from 42.9 micrograms per gram up to 3.7 milligrams per gram, averaging 817 micrograms per gram, levels comparable to those in car tires. S-BTH dominated at 49 to 715 micrograms per gram, while 6-PPD reached up to 2.7 milligrams per gram and its chemical cousin IPPD up to 921 micrograms per gram. DPG, aniline—a degradation product of several accelerators—and the cyclic amines CPU and DCU were also widespread. The chemical fingerprints of these components closely resemble those of automotive rubber, meaning the same additives raising environmental concerns are sitting inside the equipment that handles milk every day.

The researchers also rinsed the interior surfaces of these components with methanol to estimate how much of the additive load could be released on contact. This worst-case solubilization test does not replicate real milking conditions—milk is an aqueous, fatty matrix rather than an organic solvent—but it demonstrated that the compounds are available for leaching, and that what comes off the surface mirrors the composition of the bulk rubber. The authors stress that no formal migration test was performed, so compliance with existing migration limits cannot be assessed either way. Still, the results establish a theoretically plausible second pathway: rubber parts in milking machines and dairy processing equipment could, under the right conditions of temperature, contact time, and fat content, transfer their additives directly into milk.

That possibility lands in a regulatory gray zone. Under German Federal Institute for Risk Assessment recommendations, milking equipment rubber is generally classified as category 3, short-term food contact, with compositional caps of 1.5 percent for 6-PPD, 0.3 percent for DPG, and 1 percent for S-BTH, and a migration ceiling of 0.3 milligrams per liter for 6-PPD into liquids contacted at 40 degrees Celsius for ten minutes. A 2020 French decree likewise sets specific migration limits for DPG and 6-PPD. But no compositional limits or migration criteria currently exist for the other eleven compounds detected in the dairy equipment, including 6-PPDQ, which was found directly in milk samples. The detection of a transformation product that can form as rubber ages or oxidizes in real use highlights how far regulation lags behind the chemistry.

The measured concentrations in milk were low—nanograms per liter, far below any established health threshold—and the authors are careful to frame the work as an initial occurrence study rather than a risk assessment. It does not capture daily or seasonal variability on individual farms, and it cannot disentangle environmental exposure from equipment-derived migration. But the convergence of two plausible contamination routes, the presence of chemicals with documented hepatotoxic, reproductive, and genotoxic effects in animals, and the sheer scale of global milk consumption all argue for urgency. The researchers call for long-term monitoring of air, soil, and feed on dairy farms, migration studies under realistic milking conditions, targeted risk assessments of chronic dietary exposure, and ultimately the development of safer rubber formulations for food-contact applications. For now, the message is less alarm than awareness: the rubber that keeps the modern world moving may also be leaving faint chemical fingerprints in its food supply, and those fingerprints deserve a closer look.

Subject of Research: Contamination of raw cow milk and dairy equipment with tire-derived rubber additives such as 6-PPD, 6-PPDQ, DPG, and benzothiazoles.

Article Title: Rubber-related chemical contamination in milk: Implications for dairy production systems

Article References: Breider, F., Grandjean, D., Andrey, C., Masset, T., & Brüschweiler, B. J. (2026). Rubber-related chemical contamination in milk: Implications for dairy production systems. Food Chemistry: X, 39, Article 104373. https://doi.org/10.1016/j.fochx.2026.104373

Image Credits: AI Generated

DOI: 10.1016/j.fochx.2026.104373

Keywords: tire wear particles, 6-PPD, 6-PPDQ, diphenylguanidine, benzothiazoles, raw milk, dairy production, food contamination, rubber additives, food contact materials, mass spectrometry, dietary exposure