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	<title>ceftriaxone &#8211; Science</title>
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	<title>ceftriaxone &#8211; Science</title>
	<link>https://scienmag.com</link>
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		<title>Cancer patients in Rwanda face frequent multidrug-resistant bacterial infections</title>
		<link>https://scienmag.com/cancer-patients-in-rwanda-face-frequent-multidrug-resistant-bacterial-infections/</link>
		
		<dc:creator><![CDATA[Nathaniel Bowman]]></dc:creator>
		<pubDate>Wed, 21 Oct 2026 09:42:13 +0000</pubDate>
				<category><![CDATA[Medicine]]></category>
		<category><![CDATA[antibiotic efficacy limitations due to resistance]]></category>
		<category><![CDATA[antibiotic prescribing]]></category>
		<category><![CDATA[antibiotic resistance in Escherichia coli and Klebsiella]]></category>
		<category><![CDATA[Antibiotic Stewardship]]></category>
		<category><![CDATA[antimicrobial]]></category>
		<category><![CDATA[Antimicrobial Resistance]]></category>
		<category><![CDATA[antimicrobial resistance patterns in low-resource settings]]></category>
		<category><![CDATA[cancer patients]]></category>
		<category><![CDATA[carbapenem-resistant bacteria in Rwanda]]></category>
		<category><![CDATA[ceftriaxone]]></category>
		<category><![CDATA[Escherichia coli]]></category>
		<category><![CDATA[ESKAPEE pathogens in immunocompromised patients]]></category>
		<category><![CDATA[hospital surveillance]]></category>
		<category><![CDATA[impact of multidrug resistance on cancer care]]></category>
		<category><![CDATA[microbiology study in Kigali]]></category>
		<category><![CDATA[multidrug resistance]]></category>
		<category><![CDATA[Multidrug-resistant bacterial infections in cancer patients]]></category>
		<category><![CDATA[multidrug-resistant infections in oncology patients]]></category>
		<category><![CDATA[public health implications of]]></category>
		<category><![CDATA[resistance]]></category>
		<category><![CDATA[retrospective microbiology research on bacterial infections]]></category>
		<category><![CDATA[Rwanda]]></category>
		<category><![CDATA[urinary tract infections]]></category>
		<category><![CDATA[urinary tract infections in Rwanda]]></category>
		<guid isPermaLink="false">https://scienmag.com/?p=328532</guid>

					<description><![CDATA[A retrospective study of 297 culture-confirmed infections in Rwandan cancer patients found high multidrug-resistance prevalence and limited activity of the most frequently documented empirical antibiotic.]]></description>
										<content:encoded><![CDATA[<p>Multidrug resistance was common among bacterial infections in cancer patients treated at a tertiary referral hospital in Kigali, Rwanda, according to a retrospective records study covering 2019–2024. Researchers analyzed 297 culture-confirmed infection episodes in 286 patients and found that 138 of 214 bacterial isolates classifiable under the study’s resistance definitions, or 64.5%, were resistant to antibiotics in at least three classes. The estimate was 59.5% when the denominator included the 232 isolates covered by the multidrug-resistance criteria, corresponding to a 95% confidence interval of 53.1–65.6%.</p>
<p>The study, conducted at King Faisal Hospital, focused on routine clinical microbiology records rather than prospectively following patients. Urinary tract infections were the predominant reason for culture-confirmed infection, accounting for 172 of 297 episodes, or 57.9%. Escherichia coli was the most frequently identified organism, appearing in 101 episodes, followed by Klebsiella species in 32 and Enterococcus species in 25. Members of the ESKAPEE group of pathogens accounted for 201 episodes, or 67.7%. Resistance patterns also limited the activity of commonly used empirical agents: ceftriaxone resistance was detected in 65 of 87 E. coli isolates, or 74.7%, and in 20 of 29 Klebsiella isolates, or 69.0%. Among 13 Acinetobacter isolates for which carbapenem results could be assessed, eight, or 61.5%, were carbapenem resistant.</p>
<p>Modified Poisson regression found that multidrug-resistance prevalence did not differ significantly by infection type when bloodstream infections and skin and soft-tissue infections were each compared with urinary tract infections. The adjusted prevalence ratio was 0.94 for bloodstream infection, with a 95% confidence interval of 0.67–1.31, and 0.98 for skin and soft-tissue infection, with an interval of 0.72–1.34. Multidrug resistance was less prevalent among gram-positive isolates than among the comparison group, with an adjusted prevalence ratio of 0.42 and a 95% confidence interval of 0.21–0.85; the authors attributed this pattern to Enterococcus species. The observational design, incomplete routine susceptibility panels and restriction to a single tertiary hospital limit how broadly the findings can be applied.</p>
<p>The analysis also examined empirical antibiotic regimens recorded in the electronic medical record for 105 episodes, including 100 involving inpatients. These records were assessed against the World Health Organization AWaRe framework and Rwanda’s 2022 Standard Treatment Guidelines. Adherence to the national guideline was particularly low for urinary tract infections: only one of 43 eligible regimens, or 2.3%, matched the recommended treatment. Ceftriaxone was the most frequently documented empirical agent, but the laboratory findings indicated limited in vitro activity against the organisms most commonly recovered. Outpatient empirical prescribing was rarely documented, preventing its evaluation and limiting assessment of prescribing practices outside the inpatient setting.</p>
<p>The findings indicate a need to examine whether oncology-specific empirical protocols based on local susceptibility data could improve infection management in Rwanda, but the researchers said such protocols should be evaluated prospectively and include clinical outcomes. They also called for AWaRe-aligned stewardship, stronger documentation of antibiotic prescribing, particularly for outpatients, and better linkage of cancer-ward data with national antimicrobial-resistance surveillance. The study does not establish that a particular antibiotic regimen improves patient outcomes, nor does it demonstrate that the recorded prescribing practices caused resistance. Instead, it documents a local mismatch between empirical treatment, national recommendations and the susceptibility patterns observed in a vulnerable hospital population.</p>
<p><strong>Subject of Research:</strong> Antimicrobial resistance and empirical antibiotic prescribing in cancer patients with culture-confirmed infections in Rwanda</p>
<p><strong>Article Title:</strong> Antimicrobial resistance and documented empirical antibiotic prescribing among cancer patients with culture-confirmed infections at a tertiary referral hospital in Rwanda, 2019–2024</p>
<p><strong>Article References:</strong> Asuman, B. N., Dukundane, D., Kreuger, M. J., Ganal, S., Stete, K., Grundmann, H., &amp; Eichel, V. M. (2026). Antimicrobial resistance and documented empirical antibiotic prescribing among cancer patients with culture-confirmed infections at a tertiary referral hospital in Rwanda, 2019–2024. <em>BMC Infectious Diseases</em>. <a href="https://doi.org/10.1186/s12879-026-14689-2" rel="noopener noreferrer">https://doi.org/10.1186/s12879-026-14689-2</a></p>
<p><strong>Image Credits:</strong> AI Generated</p>
<p><strong>DOI:</strong> <a href="https://doi.org/10.1186/s12879-026-14689-2" rel="noopener noreferrer">10.1186/s12879-026-14689-2</a></p>
<p><strong>Keywords:</strong> antimicrobial resistance, cancer patients, Rwanda, antibiotic prescribing, multidrug resistance, Escherichia coli, ceftriaxone, urinary tract infections, hospital surveillance, antibiotic stewardship, Antimicrobial, resistance</p>
]]></content:encoded>
					
		
		
		<post-id xmlns="com-wordpress:feed-additions:1">328532</post-id>	</item>
		<item>
		<title>Azithromycin Resistance in Gonorrhea Shifts Genetic Ground, Challenging Molecular Surveillance</title>
		<link>https://scienmag.com/azithromycin-resistance-in-gonorrhea-shifts-genetic-ground-challenging-molecular-surveillance/</link>
		
		<dc:creator><![CDATA[Juliet Wilcox]]></dc:creator>
		<pubDate>Sun, 13 Sep 2026 03:20:13 +0000</pubDate>
				<category><![CDATA[Medicine]]></category>
		<category><![CDATA[23S rRNA mutations]]></category>
		<category><![CDATA[Antimicrobial Resistance]]></category>
		<category><![CDATA[azithromycin resistance]]></category>
		<category><![CDATA[Azithromycin resistance in gonorrhea]]></category>
		<category><![CDATA[ceftriaxone]]></category>
		<category><![CDATA[Ceftriaxone and azithromycin dual therapy]]></category>
		<category><![CDATA[Development of new antibiotics for gonorrhea]]></category>
		<category><![CDATA[efflux pumps]]></category>
		<category><![CDATA[Emerging resistance in sexually transmitted infections]]></category>
		<category><![CDATA[Fitness costs and advantages of resistance genes]]></category>
		<category><![CDATA[Genetic mechanisms of gonorrhea resistance]]></category>
		<category><![CDATA[genomic epidemiology]]></category>
		<category><![CDATA[Global gonorrhea treatment challenges]]></category>
		<category><![CDATA[Gonorrhea antimicrobial resistance]]></category>
		<category><![CDATA[gonorrhea treatment]]></category>
		<category><![CDATA[Impact of antimicrobial resistance on gonorrhea management]]></category>
		<category><![CDATA[molecular diagnostics]]></category>
		<category><![CDATA[molecular surveillance]]></category>
		<category><![CDATA[Molecular surveillance of gonorrhea]]></category>
		<category><![CDATA[mtr mosaic variants]]></category>
		<category><![CDATA[Neisseria gonorrhoeae]]></category>
		<category><![CDATA[Neisseria gonorrhoeae drug resistance]]></category>
		<category><![CDATA[WHO GASP]]></category>
		<category><![CDATA[WHO guidelines for gonorrhea treatment]]></category>
		<guid isPermaLink="false">https://scienmag.com/?p=201212</guid>

					<description><![CDATA[Rising azithromycin resistance in Neisseria gonorrhoeae is increasingly driven by mosaic mtr efflux variants rather than classic 23S rRNA mutations, complicating molecular surveillance assays.]]></description>
										<content:encoded><![CDATA[<p>Neisseria gonorrhoeae, the bacterium responsible for gonorrhea, remains the second most prevalent bacterial sexually transmitted infection worldwide and has become a central figure in the escalating global antimicrobial resistance crisis. The World Health Organization has classified the pathogen as a high-priority organism precisely because of its extraordinary capacity to acquire resistance to every antimicrobial agent recommended for empirical therapy. Resistance determinants accumulate in gonococcal populations, sometimes imposing fitness costs and sometimes conferring advantages depending on genetic and environmental context, and the result is a treatment landscape that grows narrower by the year. Currently, a single intramuscular one-gram dose of ceftriaxone stands as the WHO-recommended first-line treatment for uncomplicated gonorrhea, while the therapeutic pipeline behind it remains thin, with only a handful of new agents in late-stage clinical development.</p>
<p>The history of dual therapy with ceftriaxone and azithromycin illustrates how quickly the situation can change. The combination was introduced as a strategic response to concerns about ceftriaxone monotherapy failure, and it carried the added benefit of activity against Chlamydia trachomatis and Mycoplasma genitalium, which frequently co-occur with gonorrhea. In its early years the strategy worked in many settings, because most ceftriaxone-resistant gonococcal strains were still susceptible to azithromycin, and the dual approach helped slow the international spread of ceftriaxone resistance. Over the past five years, however, azithromycin resistance has risen disturbingly across the globe, undermining the drug&#8217;s value within dual therapy and threatening the efficacy of current treatment protocols. Contributing factors include extensive and often inappropriate antibiotic use, suboptimal diagnostic practices, limited surveillance systems, and delayed updates to clinical guidelines.</p>
<p>The future therapeutic landscape appears increasingly precarious. Two novel antimicrobials, zoliflodacin and gepotidacin, have recently been approved for uncomplicated gonorrhea, yet few additional agents are in clinical development. At the same time, resistance to ceftriaxone itself continues to climb in many regions, and strains with concurrent resistance to both ceftriaxone and azithromycin have now been reported in several WHO regions. High treatment costs further restrict access in resource-limited settings, where surveillance and control measures are often weakest, compounding the risk that resistance emerges and spreads undetected. Without new therapeutic strategies, enhanced global surveillance and robust research investment, gonorrhea could become progressively harder to treat, with rising morbidity, complications and treatment failures.</p>
<p>Azithromycin is an oral macrolide long used against chlamydial and mycoplasmal infections, and it once demonstrated good efficacy against gonococci as well. Its widespread availability, particularly where antibiotics can be obtained without prescription or regulation, has contributed significantly to the development of resistance. Over the past decade, azithromycin resistance has steadily increased in both high- and low-income countries, with marked geographic variability shaped by local treatment practices, surveillance infrastructure and antibiotic consumption patterns. Although azithromycin is no longer routinely recommended for gonorrhea in many settings, rising resistance limits its remaining utility and underscores why continued antimicrobial resistance surveillance matters.</p>
<p>The numbers tell a sobering story. A retrospective genomic surveillance study by Daniel Golparian and colleagues, published in The Lancet Microbe, examined N. gonorrhoeae isolates collected across 21 European Economic Area countries in 2020 through the European Gonococcal Antimicrobial Surveillance Programme. It found that azithromycin resistance, defined by the EUCAST epidemiological cut-off of MIC greater than 1 mg/L, had risen to 9.4 percent of isolates, up from 8.0 percent in 2018. In the United States, resistance climbed from 0.01 percent in 1992 to 0.4 percent by 2012, then surged fourfold from 0.6 percent in 2013 to 2.5 percent in 2014, reaching 4.6 percent in 2018 and 5.9 percent by 2019 among isolates with elevated MICs. Globally, the WHO Gonococcal Antimicrobial Surveillance Programme reported that 46 of 53 countries, or 87 percent, detected azithromycin-resistant isolates in 2022, and 36 countries reported resistance in at least 5 percent of isolates.</p>
<p>Regional heterogeneity is striking. In the WHO Western Pacific region, seven of eight reporting countries detected resistant isolates in 2022, with Brunei, Cambodia, China, Japan and Singapore each reporting resistance in at least 5 percent of isolates, while Australia and New Zealand recorded lower levels. China&#8217;s Gonococcal Resistance Surveillance Program documented azithromycin resistance reaching 16.9 percent in 2022, a substantial increase over the preceding five years, whereas all isolates reported from the Philippines remained susceptible. Surveillance itself faces structural challenges: while high-income countries maintain robust systems, reporting is inconsistent in low- and middle-income countries due to constraints in laboratory capacity, funding and infrastructure. Only 77 countries and territories reported gonococcal resistance data to WHO GASP during 2019 to 2022, and the absence of data from parts of Africa and Southeast Asia means the true global extent of resistance, and of dual-therapy treatment failures, may be significantly underreported.</p>
<p>Understanding the molecular machinery behind resistance clarifies why surveillance is difficult. Azithromycin inhibits bacterial protein synthesis by binding the peptidyltransferase region of domain V of the 23S rRNA in the 50S ribosomal subunit, blocking peptide exit. Resistance arises through several mechanisms: mutations in the 23S rRNA itself, particularly A2059G and C2611T, alter the drug-binding site; the A2059G transition in all four rRNA alleles produces extraordinarily high MICs of 256 to 4096 mg/L, while C2611T yields moderate resistance of 2 to 32 mg/L. Acquired erm genes encoding rRNA methylases can modify the target, though they have become rare in recent isolates. Mutations in rplD and rplV, encoding ribosomal proteins L4 and L22, moderately raise MICs, and efflux pump overexpression adds another layer of resistance.</p>
<p>Efflux is now central to the story. The MtrCDE pump, the best-characterized system, expels macrolides when its regulator MtrR is disabled by mutations such as G45D, or when promoter mutations, including a single-nucleotide deletion in a 13-base-pair inverted repeat, increase pump transcription. Mosaic mtr alleles, acquired through recombination with sequences from Neisseria meningitidis or Neisseria lactamica, substantially raise azithromycin MICs by altering both the pump and its regulation. The MacAB and mef-encoded efflux systems may also contribute, though they remain less studied in gonococci. Collectively, these mechanisms reveal a complex and geographically variable genetic architecture of resistance.</p>
<p>That variability is precisely what undermines molecular diagnostics. Historically, 23S rRNA mutations were the predominant, best-characterized determinants, and systematic reviews confirm that assays targeting A2059G accurately detect high-level resistance while C2611T assays identify moderate resistance. But the European genomic surveillance revealed a decisive shift: only 10.5 percent of azithromycin-resistant isolates in 2020 carried 23S rRNA mutations, down from 24.1 percent in 2018, while roughly 89 percent instead carried mtrD/mtrR promoter mosaic 2 or semi-mosaic mtrD variants. The authors attribute the resistance surge to the expansion of specific NG-STAR clonal complexes, notably CC63, CC168 and CC213 harboring the mosaic promoter, plus the emergence of novel CC1031 carrying a semi-mosaic mtrD variant. An assay built for the old targets would miss the dominant circulating resistance genotypes.</p>
<p>The implications for public health are clear. The WHO advocates molecular assays that detect resistance markers to guide therapy and support stewardship, but their validity, accuracy and specificity falter when marker distributions differ across regions; in areas dominated by mtrD mosaic variants, a 23S rRNA-focused assay would yield a very low positive predictive value. Tailoring molecular targets to local genetic epidemiology is therefore essential. In low- and middle-income countries where routine whole-genome sequencing is impractical, a pragmatic sentinel-site strategy, with representative laboratories performing susceptibility testing and periodically referring isolates to regional reference centers for genomic characterization, offers a feasible alternative. A standardized minimum dataset reported to WHO GASP, covering susceptibility results, specimen source, geography, collection year and resistance determinants, would enable continuous refinement of regionally calibrated assays. The shift from dual therapy toward ceftriaxone monotherapy may also reshape selection pressure on azithromycin resistance, though the magnitude and direction of that effect remain uncertain, since macrolide use for other infections, fitness effects and lineage dynamics all play a role. Sustained phenotypic and genomic surveillance, novel antimicrobials and combination therapies, and collaboration among researchers, clinicians and public health stakeholders will determine whether gonorrhea remains treatable in the decade ahead.</p>
<p><strong>Subject of Research:</strong> Heterogeneity of azithromycin resistance markers in Neisseria gonorrhoeae and the challenges of implementing molecular assays for routine antimicrobial resistance surveillance</p>
<p><strong>Article Title:</strong> Heterogeneity of azithromycin resistance markers in Neisseria gonorrhoeae and challenges in implementing molecular assays for routine surveillance</p>
<p><strong>Article References:</strong> Yuan, Q., Xiu, L., &amp; Peng, J. (2026). Heterogeneity of azithromycin resistance markers in Neisseria gonorrhoeae and challenges in implementing molecular assays for routine surveillance. <em>New Microbes and New Infections, 73</em>, Article 101838. <a href="https://doi.org/10.1016/j.nmni.2026.101838" rel="noopener noreferrer">https://doi.org/10.1016/j.nmni.2026.101838</a></p>
<p><strong>Image Credits:</strong> AI Generated</p>
<p><strong>DOI:</strong> <a href="https://doi.org/10.1016/j.nmni.2026.101838" rel="noopener noreferrer">10.1016/j.nmni.2026.101838</a></p>
<p><strong>Keywords:</strong> Neisseria gonorrhoeae, azithromycin resistance, antimicrobial resistance, molecular surveillance, 23S rRNA mutations, mtr mosaic variants, efflux pumps, WHO GASP, ceftriaxone, gonorrhea treatment, genomic epidemiology, molecular diagnostics</p>
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