The research, led by Julie Teresa Shapiro of the University of Florida and the French Agency for Food, Environmental and Occupational Health and Safety, together with colleagues from the University of Copenhagen, Aarhus University, the University of Pretoria, and the University of Eswatini, analyzed fecal samples from 109 individual little free-tailed bats captured between November 2015 and July 2016 at 28 sites across the Lowveld region of eastern Eswatini. This area, part of the Maputaland-Pondoland-Albany biodiversity hotspot, is dominated by commercial sugarcane plantations, subsistence maize fields, grazing lands, rural villages, and protected parks, making it an ideal natural laboratory for asking how anthropogenic disturbance shapes the invisible ecosystems inside wildlife.

The team used a molecular technique called amplicon sequencing, targeting the V3–V4 region of the 16S ribosomal RNA gene, a genetic marker widely used to identify bacteria. After extracting DNA from fecal samples preserved with silica gel, the researchers amplified the bacterial marker, sequenced the products on an Illumina MiSeq platform, and processed the reads through the DADA2 pipeline, which identifies distinct amplicon sequence variants, or ASVs, the finest practical resolution of bacterial identity. Rigorous contamination controls, including extraction blanks, PCR blanks, and the requirement that a bacterial variant appear in at least two of three PCR replicates before being counted, ensured the results reflected genuine biology rather than laboratory artifacts.

The scale of bacterial diversity they uncovered was impressive. Across the 109 bats, the team identified 2,249 unique bacterial ASVs, and a statistical technique called rarefaction, which plots species accumulation against sampling effort, showed the curves reaching a clear asymptote. The Chao1 estimator, a method for extrapolating total richness from observed data, suggested the true diversity was between 2,250 and 2,253 species, meaning the researchers had captured essentially the complete bacterial inventory of this species’ gut in the region. Individual bats carried anywhere from 3 to 185 ASVs, with a mean of 47, and phylogenetic diversity, measured with Faith’s index, ranged from 0.6 to 24.1.

Perhaps the most striking pattern was the extraordinary individuality of each bat’s microbiome. Fully 72 percent of the identified bacterial variants, some 1,622 of them, were found in only a single bat, and fewer than 1 percent appeared in more than a quarter of the animals sampled. The most common single variant, an unknown species of Mycoplasma, was still detected in only 66 percent of bats. The dominant phyla across the population were Proteobacteria and Firmicutes, present in every individual, followed by Actinobacteria in 84 percent and Bacteroidota in just over half. The researchers suggest this high individual variability likely reflects the bat’s generalist insectivorous diet: previous molecular diet studies have shown that Mops pumilus feeds on a wide and individually variable array of insect prey, and since diet is a major driver of gut microbial composition, no two bats end up with quite the same internal community.

Then came the pathogen findings. Screening the ASV table against a list of bacterial genera known to be potentially zoonotic and frequently found in bats, the team detected five: Mycoplasma, Rickettsia, Salmonella, Bartonella, and Campylobacter. Four of these occurred at remarkably high prevalence. Mycoplasma topped the list at 88 percent of individuals, present at all but two of the 17 roosts surveyed in the landscape analysis. Rickettsia was found in 36 percent of bats, Salmonella in 34 percent, and Bartonella in 23 percent, while Campylobacter appeared in just 4 percent. Co-occurrence was common: 27 bats carried two of these genera simultaneously, 23 carried three, seven carried four, and one individual harbored all five.

Crucially, none of the bats showed signs of illness. The researchers found no correlation between bacterial richness or phylogenetic diversity and body condition, calculated as mass divided by forearm length, a standard health proxy in bats. This absence of disease, combined with the sheer prevalence of the bacteria, suggests the animals are likely asymptomatic carriers, or that the detected DNA originated in their insect prey rather than establishing infection in the bats themselves. Rickettsia in particular is a common insect endosymbiont, and its presence in feces could simply reflect a recent meal of infected insects or ticks groomed off the fur. Salmonella, by contrast, is usually reported in bats at prevalences below 12 percent, making the 34 percent figure here notably high, and raising questions about environmental reservoirs such as contaminated water, which has been implicated in other studies.

The central hypothesis of the study, however, was largely not borne out. Drawing on prior work showing that habitat degradation can reduce gut microbial diversity in primates, rodents, and other bats, the researchers expected that anthropogenic land covers and fragmentation would diminish bacterial richness and shift community composition. They classified the landscape from Landsat 8 satellite imagery into savanna, sugarcane, rural settlement, and water, then calculated composition metrics and configuration metrics such as savanna edge density and a fragmentation index at both a fine scale around roosts and a landscape scale matching the bats’ nightly foraging ranges, which can exceed four kilometers. Using generalized linear mixed models and distance-based redundancy analysis, they found no association between any land cover variable and bacterial richness, phylogenetic diversity, or the prevalence of potentially pathogenic genera. Land cover explained only a small fraction, about 6.7 percent, of the variation in community composition, with fine-scale rural and savanna cover and landscape-scale sugarcane cover and savanna splitting emerging as statistically significant but weak predictors.

The authors interpret this muted response as a reflection of the species’ ecological flexibility. Unlike bats that avoid disturbed habitats, Mops pumilus actively uses and even prefers agricultural landscapes, roosting in buildings and feeding over irrigated monocultures where water and insect prey remain available year-round. Because its activity and foraging are not negatively affected by human land use, its gut microbiome may be similarly buffered. The researchers also point to factors their sampling design could not fully disentangle, including social transmission of microbes within roosts, local environmental microbial communities, and roost characteristics, any of which might outweigh landscape composition in shaping these internal ecosystems. Seasonal effects, too, remain untested, although the species neither migrates nor hibernates, which may dampen the seasonal microbiome shifts documented in other bat species.

The findings carry real weight for the One Health framework, the principle that human, animal, and environmental health are interconnected. Bats are already recognized as reservoirs of numerous viruses, and bacterial genera such as Bartonella and Mycoplasma have documented links to human disease, including Bartonella mayotimonensis carried by Myotis bats in northern Europe and Mycoplasma haemohominis carried by flying foxes in New Caledonia. While there is currently no evidence that the bacteria detected in Eswatini cause illness in the bats or can infect people, Mycoplasma species are considered emerging pathogens that have caused mortality in other wildlife, and the authors argue that continued surveillance of this abundant, human-associated bat species is warranted. As savannas across southern Africa continue to convert to agriculture, understanding which species tolerate, and which are quietly transformed by, the changing landscape will be essential for conserving both the bats and the health of the systems they inhabit.

Subject of Research: Gut microbiome diversity and potentially pathogenic bacteria in the little free-tailed bat (Mops pumilus) in relation to land cover change in Eswatini

Article Title: Gut microbiomes of the little free-tailed bat (Mops pumilus) show high prevalence of potential bacterial pathogens but limited responses to land cover

Article References: Shapiro, J. T., Barnes, C., Nielsen, I. B., Rasmussen, L., Monadjem, A., McCleery, R. A., & Hansen, A. J. (2026). Gut microbiomes of the little free-tailed bat ( Mops pumilus ) show high prevalence of potential bacterial pathogens but limited responses to land cover. Web Ecology, 26(2), 223-242. https://doi.org/10.5194/we-26-223-2026

Image Credits: AI Generated

DOI: 10.5194/we-26-223-2026

Keywords: gut microbiome, bats, Mops pumilus, 16S rRNA sequencing, bacterial pathogens, Mycoplasma, Salmonella, land cover change, Eswatini, One Health, wildlife disease, savanna

The study, led by Masoumeh Beig and co-first author Sara Hajilari, with Khalil Azizian and Ebrahim Kouhsari as equally contributing corresponding authors, followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and included studies published up to 8 February 2026. The team used R software to compute pooled prevalence estimates with 95 percent confidence intervals, quantifying heterogeneity with Cochran’s Q and tau-squared statistics. Their focus was the minimum inhibitory concentration, or MIC, the lowest concentration of an antibiotic that prevents visible bacterial growth. When MICs rise above established breakpoints, an isolate is classified as non-susceptible, signaling that standard dosing may fail at the site of infection.

Macrolides work by binding to the 50S subunit of the bacterial ribosome, blocking the exit tunnel through which newly synthesized proteins must pass. Erythromycin, the prototype 14-membered macrolide, azithromycin, a 15-membered derivative prized for its tissue penetration, and clarithromycin and roxithromycin, both 14-membered agents, all share this target. Josamycin, a 16-membered macrolide, binds somewhat differently and has retained activity where its smaller relatives have faltered. Resistance in mycoplasmas typically arises through point mutations in the 23S ribosomal RNA gene, particularly in domain V, which alter the drug-binding pocket. Because these organisms lack a cell wall, beta-lactam antibiotics such as penicillins are useless against them, leaving macrolides, tetracyclines, and fluoroquinolones as the principal therapeutic options.

The numbers assembled by the Iranian team paint a genus-specific picture. For Ureaplasma species, pooled non-susceptibility was 13.3 percent for erythromycin, 15.3 percent for roxithromycin, 9.9 percent for clarithromycin, 6.4 percent for azithromycin, and just 2.6 percent for josamycin. For Mycoplasma species, the corresponding estimates were dramatically higher: 63.4 percent for roxithromycin, 84.5 percent for clarithromycin, 78.8 percent for azithromycin, and 7.7 percent for josamycin. Erythromycin non-susceptibility in Mycoplasma reached 75.7 percent. The authors caution, however, that Mycoplasma hominis is intrinsically resistant to 14- and 15-membered macrolides, meaning pooled estimates for erythromycin, azithromycin, clarithromycin, and roxithromycin in that species reflect biology as much as acquired resistance. For M. hominis, the clinically meaningful figure is josamycin, where pooled non-susceptibility was only 6.1 percent.

Geography emerged as a significant modifier for four of the five drugs examined. The meta-analysis detected significant geographic variation in non-susceptibility for erythromycin, clarithromycin, azithromycin, and josamycin, all with P values below 0.05, while roxithromycin showed no significant regional difference, with a P value of 0.283. This pattern suggests that local prescribing habits, population structure, and transmission dynamics shape resistance profiles unevenly across the globe. In regions where azithromycin has been deployed widely, including mass drug administration campaigns and routine sexually transmitted infection management, elevated MICs appear more frequently, whereas areas with lighter macrolide pressure retain comparatively vulnerable bacterial populations.

Perhaps the most reassuring finding is what the analysis did not show. Across the entire dataset, no significant temporal trends were observed for any of the evaluated macrolides: the P value was 0.994 for erythromycin, 0.165 for roxithromycin, 0.615 for clarithromycin, 0.326 for azithromycin, and 0.467 for josamycin. In other words, resistance levels appear to have remained roughly stable over the period covered by the included studies rather than climbing year over year. The authors interpret this cautiously, noting that stability is not the same as safety. A plateau at 75 percent erythromycin non-susceptibility in Mycoplasma offers little therapeutic comfort, and the absence of a trend may simply reflect the coarse resolution of pooled cross-sectional data.

The clinical implications are direct. Urogenital mycoplasmas and ureaplasmas are associated with urethritis, cervicitis, pelvic inflammatory disease, adverse pregnancy outcomes, and complications in neonates, and they are among the most difficult sexually associated bacteria to culture, often requiring nucleic acid amplification tests for detection and specialized broth-based systems for susceptibility testing. When macrolides fail, clinicians typically turn to tetracyclines such as doxycycline or to fluoroquinolones, but resistance to those classes has also been documented in these organisms, narrowing the armamentarium further. The new pooled estimates give guideline committees a quantitative baseline for deciding when macrolide therapy remains defensible and when an alternative should be the default.

Josamycin stands out as the quiet winner of the analysis. With pooled non-susceptibility of 2.6 percent in Ureaplasma and 7.7 percent in Mycoplasma overall, and 6.1 percent in M. hominis specifically, the 16-membered macrolide demonstrated consistently low MICs across the included studies. The authors suggest it may represent a promising alternative, particularly where 14- and 15-membered agents have lost efficacy. Josamycin is not licensed in every country, and its availability varies widely, but the data provide an evidence-based argument for reconsidering its place in treatment algorithms for urogenital infections, especially in regions where azithromycin MICs have drifted upward.

For erythromycin and azithromycin, the message is restraint. The combination of high erythromycin resistance and moderate elevation of azithromycin MICs, the authors conclude, warrants cautious use of these agents, reserving them for cases where susceptibility has been confirmed or where no better option exists. Empirical macrolide monotherapy for suspected Mycoplasma-driven disease, once a reflexive choice, now carries a substantial probability of failure in many settings. The researchers emphasize that ongoing global surveillance remains essential to support evidence-based treatment guidelines, since resistance in organisms with rapid replication and frequent horizontal gene exchange can shift within years, and the fragmented geographic data they aggregated highlight how little standardized susceptibility testing exists in much of the world.

The study, published open access on 8 October 2026 and citable under DOI 10.1186/s12879-026-14585-9, was approved by the Ethics Committee of Golestan University of Medical Sciences and conducted in accordance with the Declaration of Helsinki. The authors declared no competing interests and no external funding, and they state that a language-model tool was used solely to polish the manuscript’s prose, not to collect or analyze data. As antimicrobial resistance continues to erode the utility of first-line antibiotics across the infectious disease spectrum, this meta-analysis offers both a warning and a waypoint: the macrolide era for urogenital Mycoplasma is largely over in much of the world, but for Ureaplasma, and for josamycin across both genera, carefully stewarded options remain.

Subject of Research: Global macrolide antibiotic resistance in urogenital Ureaplasma and Mycoplasma species

Article Title: Global macrolide non-susceptibility in urogenital Ureaplasma and Mycoplasma: a systematic review and meta-analysis

Article References: Beig, M., Azizian, K., Hajilari, S., Shakourzadeh, M. Z., & Kouhsari, E. (2026). Global macrolide non-susceptibility in urogenital Ureaplasma and Mycoplasma: a systematic review and meta-analysis. BMC Infectious Diseases. https://doi.org/10.1186/s12879-026-14585-9

Image Credits: AI Generated

DOI: 10.1186/s12879-026-14585-9

Keywords: antimicrobial resistance, macrolides, Ureaplasma, Mycoplasma, erythromycin, azithromycin, josamycin, minimum inhibitory concentration, systematic review, meta-analysis, sexually transmitted infections, BMC Infectious Diseases

The research team, led by Khajid Ullah Khan and Muhammad Tariq Zahid of Government College University, Lahore, together with colleagues in Pakistan and South Korea, collected 126 scorpions, 85 females and 41 males, from rocky field sites during June and July, the peak of the animals’ annual activity window. Specimens were located by day by overturning stones and by night using ultraviolet light, which causes scorpion cuticles to fluoresce. Morphological examination under a stereomicroscope documented the diagnostic features of the species, including its dark brown coloration, densely granulated carapace keels, a triangular sternum characteristic of the family Buthidae, and a bulbous reddish telson bearing a curved, dark-tipped aculeus. Females were consistently larger and thicker-bodied than males, with mean total lengths of roughly 72.8 millimeters compared with 62.9 millimeters in males, and males carried significantly more pectinal teeth, averaging about 30 to 32 per comb versus 26 in females.

To confirm species identity beyond morphology, the researchers amplified and Sanger-sequenced approximately 650 base pairs of the mitochondrial cytochrome c oxidase subunit I gene, the standard animal DNA barcode. BLAST comparison against the NCBI GenBank database returned nucleotide identities of 96.95 and 96.81 percent with existing H. tamulus sequences, and maximum-likelihood phylogenetic analysis in MEGA11 clustered the new sequences firmly within the species. The roughly three percent divergence from the nearest reference strain, which originated from a commercial insect market in China with undocumented provenance, suggests notable geographic structuring within the species, a pattern consistent with the deep intraspecific lineages documented in other scorpion genera such as Scorpio in the Levant and Alpiscorpius in the European Alps.

The centerpiece of the study was its metataxonomic analysis of the gut contents of six adult scorpions, three males and three females, dissected aseptically after surface sterilization. Genomic DNA was extracted with a bead-beating kit and sequenced on an Oxford Nanopore MinION flow cell using primers targeting the full V1 through V9 hypervariable regions of the 16S rRNA gene. The run produced 355,264 high-quality reads, averaging about 71,000 per sample with a mean length of approximately 1,390 nucleotides, effectively covering the entire gene. Because nanopore sequencing carries higher raw error rates than short-read platforms, the team clustered sequences de novo into operational taxonomic units at a deliberately relaxed 85 percent identity threshold using VSEARCH, then classified them against the SILVA reference database within the QIIME 2 pipeline, removing putative contaminants flagged in negative controls.

The results reveal a gut community dominated overwhelmingly by two bacterial phyla. Firmicutes accounted for between 79.5 and 90.4 percent of sequences across individuals, followed by Proteobacteria at 9.5 to 20.5 percent, while Actinobacteriota and Bacteroidota were barely detectable. At the class level, Bacilli made up roughly 73 percent of the community, with Gammaproteobacteria and Mollicutes contributing about 13 and 7 percent respectively. Four genera stood out as the core microbiota: Bacillus, Mycoplasma, Pantoea, and Enterobacter together comprised approximately 84 percent of all recovered 16S sequences. Bacillus alone represented 17 to 30 percent of the gut community, echoing recent findings in the black scorpion Heterometrus longimanus, where the same genus also dominates. The authors suggest Bacillus may function as a key endosymbiont, supporting antioxidant defenses, gut barrier integrity, and the synthesis of vitamins and amino acids for the host.

Perhaps the most evolutionarily intriguing member of the community is Mycoplasma, a genus of wall-less bacteria that has repeatedly surfaced in scorpion microbiome surveys. Previous work by Bolaños and colleagues documented Mycoplasma lineages in 15 scorpion morphospecies across Mexico, with cophylogenetic analysis suggesting cospeciation between the bacteria and their hosts. The new Pakistani data reinforce the idea that Mycoplasma is an indigenous, long-term associate of scorpions rather than a transient dietary contaminant, a conclusion paralleled by reports of Mycoplasma comprising up to 40 percent of the respiratory microbiota in some snake families. In the present study, Mycoplasma was roughly twice as abundant in females, averaging 10.5 percent relative abundance, as in males at 5.3 percent.

Sex emerged as a consistent theme throughout the diversity analyses. Alpha diversity metrics, including observed species, Chao1, Shannon, and Simpson indices, showed that female scorpions harbored markedly richer and more evenly distributed bacterial communities, whereas male guts were dominated by a smaller set of taxa. Two intestinal fermenters, Enterococcus and Romboutsia, were significantly enriched in females. Both genera are associated with carbohydrate and bile acid metabolism in nutrient-rich gut environments, and the authors speculate that the reproductive energy demands of females may create a more favorable niche for these bacteria, potentially influencing host energy harvest from food. Comparable sex-dependent microbiome patterns have been reported in ticks, where males and females of species such as Amblyomma americanum carry distinct communities, and in the wolf spider Pardosa astrigera, where seasonal and physiological state modulate sex-specific diversity.

To move beyond taxonomy, the researchers applied PICRUSt2, a bioinformatic tool that infers metagenome functions from 16S profiles by matching marker genes against reference genomes. The analysis predicted 23 enriched MetaCyc metabolic pathways spanning energy metabolism, amino acid and lipid biosynthesis, nucleotide metabolism, and the biodegradation of xenobiotic compounds. Male samples appeared enriched for energy metabolism and biosynthetic routes, while female samples showed greater representation of lipid metabolism and fatty acid biosynthesis pathways, hints that the sex-specific microbial differences may extend into function. The authors are careful to stress, however, that PICRUSt2 output is indicative rather than definitive: it does not measure actual gene expression, and the predictions require validation through shotgun metagenomics or transcriptomics, particularly given the study’s small sample of six individuals.

Situated in a broader ecological context, the findings portray scorpions as hosting a moderately diverse microbiome that sits above the extremely depauperate communities of social spiders, which average a Shannon index of just 0.66, yet below the hundreds to thousands of operational taxonomic units recoverable from soil or lepidopteran eggs. The overlap between the H. tamulus core genera and those documented in wolf spiders, crab spiders, and moths suggests a partially conserved gut microbial blueprint across predatory arthropods. The authors also raise an untested but plausible transmission hypothesis: because scorpions exhibit extensive brood care, including mothers provisioning enzymatically treated prey to offspring, maternal transfer could explain how these symbionts persist across generations, a mechanism previously documented in brown widow spiders.

As a first baseline for a medically iconic species in a previously unsampled region of Pakistan, the study opens concrete research avenues. Bacillus and Mycoplasma emerge as prime candidates for integrated follow-up work combining metagenomics, transcriptomics, and analysis of the venom apparatus microbiome, where Proteobacteria have been shown in other species to exceed half of the bacterial load and may contribute to nutrient cycling within the telson. Whether the gut community actively underpins H. tamulus adaptation to arid, resource-limited habitats, as microbiome-mediated stress tolerance studies in spiders and flies suggest it might in other arthropods, remains a compelling but unproven hypothesis. The authors are explicit that their six-individual sample cannot define a species-wide core microbiome; larger geographic surveys and controlled experiments will be needed before the hidden microbial partners of the world’s deadliest scorpion can be fully credited with any of its remarkable ecological success.

Subject of Research: Gut bacterial microbiome diversity and functional potential of the Indian red scorpion Hottentotta tamulus in Pakistan

Article Title: Gut Microbiome Diversity, Functional Potential, and Ecological Relevance of Hottentotta tamulus

Article References: Khan, K. U., Zahid, M. T., Mustafa, G., Tanpure, R. S., Tahir, H. M., Kumar, R., Kim, D.-W., Park, H.-K., & Jeon, B.-H. (2026). Gut Microbiome Diversity, Functional Potential, and Ecological Relevance of Hottentotta tamulus. MicrobiologyOpen, 15(5), Article e70373. https://doi.org/10.1002/mbo3.70373

Image Credits: AI Generated

DOI: 10.1002/mbo3.70373

Keywords: Hottentotta tamulus, Indian red scorpion, gut microbiome, 16S rRNA sequencing, Oxford Nanopore, Firmicutes, Bacillus, Mycoplasma, PICRUSt2, sexual dimorphism, scorpion venom, Pakistan