Colistin-resistant Escherichia coli with mcr genes in the livestock of rural small-scale farms in Ecuador. - Related Documents




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195101.0000Colistin-resistant Escherichia coli with mcr genes in the livestock of rural small-scale farms in Ecuador. OBJECTIVE: Emergence and dissemination of colistin-resistant (Co-R) bacteria harboring mobile colistin resistance genes pose a threat for treatment of infections caused by multi-drug resistant bacteria. Although the worldwide spread of Co-R bacteria is known, the precise state of Co-R bacterial dissemination in livestock of Andean countries remains unclear. Therefore, we investigated mcr-containing Co-R Escherichia coli dissemination in livestock on small-scale farms in two socioecologically different regions of Ecuador: the Amazonian rain-forest and the Pacific Coast. RESULTS: Sixty-six rectal swab samples from 34 pigs and 32 chickens, from five farms in the two regions, were assessed for the dissemination of Co-R E. coli using the selective medium CHROMagar™ COL-APSE. mcr-containing Co-R E. coli were detected in the specimens at a high rate (47%; 31/66), but the detection rates of the two regions were not statistically different. Both chickens and pigs showed similar detection rates. All Co-R E. coli isolates harbored mcr-1. The minimum inhibitory concentrations of colistin were ≥ 8 mg/L, and 67.7% (21/31) of the Co-R isolates were multi-drug resistant. Pulsed-field gel electrophoresis revealed the limited relation between isolates. Thus, we revealed the high rate of widespread dissemination of Co-R bacteria in livestock regardless of the socioecological conditions in Ecuador.201930832731
194910.9999Multidrug Resistance Profiles and Resistance Mechanisms to β-Lactams and Fluoroquinolones in Bacterial Isolates from Hospital Wastewater in Bangladesh. Multidrug resistance (MDR) is one of the deadliest public health concerns of the 21st century, rendering many powerful antibiotics ineffective. The current study provides important insights into the prevalence and mechanisms of antibiotic resistance in hospital wastewater isolates. In this study, we determined the MDR profile of 68 bacterial isolates collected from five different hospitals in Dhaka, Bangladesh. Of them, 48 bacterial isolates were identified as Enterobacteriaceae. Additionally, we investigated the prevalence and distribution of five beta-lactam resistance genes, as well as quinolone resistance mechanisms among the isolates. The results of this study showed that 87% of the wastewater isolates were resistant to at least three different antibiotic classes, as revealed using the disc diffusion method. Resistance to β-lactams was the most common, with 88.24% of the isolates being resistant, closely followed by macrolides (80.88% resistant). Polymyxin was found to be the most effective against wastewater isolates, with 29.41% resistant isolates. The most common β-lactam resistance genes found in wastewater isolates were bla(TEM) (76.09%), bla(CTX-M1) (71.74%), and bla(NDM) (67.39%). Two missense mutations in the quinolone resistance-determining region (QRDR) of gyrA (S83L and D87N) and one in both parC (S80I) and parE (S458A) were identified in all isolates, and one in parE (I529L), which had not previously been identified in Bangladesh. These findings suggest that hospital wastewater acts as an important reservoir of antibiotic-resistant bacteria wherein resistance mechanisms to β-lactams and fluoroquinolones are obvious. Our data also emphasize the need for establishing a nationwide surveillance system for antibiotic resistance monitoring to ensure that hospitals sanitize their wastewater before disposal, and regulation to ensure hospital wastewater is kept away from community settings.202337623228
161920.9999Evidence of colistin resistance genes (mcr-1 and mcr-2) in wild birds and its public health implication in Egypt. BACKGROUND: Antimicrobial resistance has become one of the most severe global threats to human and veterinary Medicine. colistin is an effective therapeutic agent against multi-drug-resistant pathogens. However, the discovery of transferable plasmids that confer resistance to colistin (mcr-1) has led to challenges in medical science. This study describes the role of wild birds in the harbouring and environmental spread of colistin-resistant bacteria, which could pose a potential hazard to human and animal health. METHODS: In total, 140 faecal samples from wild birds (migratory and resident birds) were tested. Twenty surface water samples were collected from the area in which wild bird trapping was conducted, and 50 human stool samples were collected from individuals residing near the surface water sources and farm buildings. Isolation and identification of Enterobacteriaceae and Pseudomonas aeruginosa from the different samples were performed using conventional culture techniques and biochemical identification. PCR amplification of the mcr genes was performed in all positive isolates. Sequencing of mcr-1 genes from three randomly selected E. coli carrying mcr-1 isolates; wild birds, water and humans was performed. RESULT: The bacteriological examination of the samples showing isolates of Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca and P. aeruginosa. The results of multiplex PCR of the mcr genes revealed that E. coli was the most prevalent gram-negative bacterium harbouring the mcr genes, whereas a low prevalence was observed for K. pneumoniae. The prevalence of mcr-1 in resident birds, migratory birds, water sources and humans were 10.4, 20,16.6 and 9.6% while the prevalence of mcr-2 were 1.4, 3.6, 11.1 and 9.6%, respectively. Sequencing of the mcr-1 gene from the three E. coli carrying mcr-1 isolates indicated a possible correlation between the wild bird and surface water isolates. CONCLUSION: The detection of mcr-1-positive bacteria in wild birds in Egypt indicates the possible environmental dissemination of this gene through bird activity. The impact of the interaction between domestic and wild animals on public health cannot be overlooked.201931827778
194830.9999Identification and Characterization of Cefotaxime Resistant Bacteria in Beef Cattle. Third-generation cephalosporins are an important class of antibiotics that are widely used in treatment of serious Gram-negative bacterial infections. In this study, we report the isolation of bacteria resistant to the third-generation cephalosporin cefotaxime from cattle with no previous cefotaxime antibiotic exposure. The prevalence of cefotaxime-resistant bacteria was examined by a combination of culture based and molecular typing methods in beef cattle (n = 1341) from 8 herds located in North Central Florida. The overall prevalence of cefotaxime-resistant bacteria was 15.8% (95% CI: 13.9, 17.8), varied between farms, and ranged from 5.2% to 100%. A subset of isolates (n = 23) was further characterized for the cefotaxime minimum inhibitory concentration (MIC) and antibiotic susceptibility against 10 different antibiotics, sequencing of nine β- lactamase genes, and species identification by 16S rRNA sequencing. Most of the bacterial isolates were resistant to cefotaxime (concentrations, > 64 μg/mL) and showed high levels of multi-drug resistance. Full length 16S rRNA sequences (~1300 bp) revealed that most of the isolates were not primary human or animal pathogens; rather were more typical of commensal, soil, or other environmental origin. Six extended spectrum β-lactamase (ESBL) genes identical to those in clinical human isolates were identified. Our study highlights the potential for carriage of cefotaxime resistance (including "human" ESBL genes) by the bacterial flora of food animals with no history of cefotaxime antibiotic exposure. A better understanding of the origin and transmission of resistance genes in these pre-harvest settings will be critical to development of strategies to prevent the spread of antimicrobial resistant microorganisms to hospitals and communities.201627642751
195040.9999In treacherous waters: detection of colistin-resistant bacteria in water and plastic litter from a recreational estuary. Colistin resistance poses a major therapeutic challenge and resistant strains have now been reported worldwide. However, the occurrence of such bacteria in aquatic environments is considerably less understood. This study aimed to isolate and characterize colistin-resistant strains from water and plastic litter collected in an urban recreational estuary. Altogether, 64 strains with acquired colistin resistance were identified, mainly Acinetobacter spp. and Enterobacter spp. From these, 40.6% were positive for at least one mcr variant (1-9), 26.5% harbored, extended-spectrum beta-lactamases, 23.4% harbored, sulfonamide resistance genes, and 9.3% harbored, quinolone resistance genes. merA, encoding mercury resistance, was detected in 10.5% of these strains, most of which were also strong biofilm producers. The minimum inhibitory concentration toward colistin was determined for the mcr-positive strains and ranged from 2 to ≥512 µg ml-1. Our findings suggest that Gram-negative bacteria highly resistant to a last-resort antimicrobial can be found in recreational waters and plastic litter, thereby evidencing the urgency of the One Health approach to mitigate the antimicrobial resistance crisis.202439227173
161350.9999Research note: Occurrence of mcr-encoded colistin resistance in Escherichia coli from pigs and pig farm workers in Vietnam. WHO considers colistin as a highest priority critically important drug for human health, and occurrence of colistin-resistant bacteria in livestock is of health concern. The current study determined occurrence of colistin-resistant Escherichia coli in pigs and workers at pig farms in Vietnam, and investigated the genetic background for resistance. Colistin-resistant E. coli were detected from pigs in 53/116 (45.7%) farms, and from workers taking care of the pigs in 21/94 (22.3%) farms. Colistin-resistant isolates showed MIC to colistin between 4-16 mg/L, they were multidrug resistant (99%) and resistance was caused by the presence of mcr-1 genes in 97/102 (95.1%) E. coli from pigs and in 31/34 (91.1%) isolates from humans. mcr-1 is considered a plasmid-encoded gene, but this was not confirmed in the current investigation. In total, one pig isolate carried both mcr-1 and mcr-3 genes, whereas mcr-2, mcr-4 and mcr-5 genes were not detected. Shared resistance profiles between pig and human isolates on the same farm was only observed in four farms. The study showed that commensal E. coli from pigs in Vietnam constitute a reservoir for colistin-resitant E. coli, however, further studies are needed to confirm that mcr genes are associated with plasmids and their importance for human health.202037333956
273260.9999Biofilms in hospital effluents as a potential crossroads for carbapenemase-encoding strains. Bacterial resistance to carbapenem, which is mainly due to the successful dissemination of carbapenemase-encoding genes, has become a major health problem. Few studies have aimed to characterize the level of resistance in the environment, notably in hospital wastewater, which is a likely hotspot for exchange of antibiotic resistance genes. In this work, we looked for the presence of imipenem-resistant bacteria and imipenem in the effluent of the teaching hospital of Clermont-Ferrand, France. Selective growth of bacteria from 14-day old biofilms formed in the pipe sewer showed that 22.1% of the isolates were imipenem-resistant and identified as Aeromonas (n = 23), Pseudomonas (n = 10), Stenotrophomonas (n = 4) and Acinetobacter (n = 1). Fifteen of these strains harbored acquired carbapenemase-encoding genes bla(VIM) (n = 11), bla(OXA-48) (n = 2), bla(GES) (n = 1), bla(NDM) (n = 1). All isolates also harbored associated resistances to aminoglycosides, fluoroquinolones and/or tetracyclin. S1-nuclease pulsed-field gel electrophoresis analysis of eight selected isolates showed that four of them harbored one to two plasmids of molecular weight between 48.5 Kb and 194 Kb. In vitro transformation assays evidenced the presence of bla(VIM) and bla(NDM) on plasmids with the bla(VIM) harboring 80 Kb plasmid having conjugative capacity. The predicted environmental concentration of imipenem in the hospital effluent was 3.16 μg/L, suggesting that biofilm bacteria are subjected to sub-MICs of imipenem within the effluent. However, no imipenem molecule was detected in the hospital effluent, probably owing to its instability: in vitro assays indicated that imipenem's biological activity was no longer detectable after 45 h of storage. However, the predictive value of the hazard quotient relative to the development of resistance was >1.0 (HQr = 28.9 ± 1.9), which indicates a possible risk. The presence of carbapenemase-encoding genes in hospital effluent biofilm strains and their ability to transfer are therefore a potential hazard that should not be neglected and points to the need for monitoring antibiotic resistance in hospital wastewater.201930530220
274670.9998Antibiotic Resistance and Antibiotic Resistance Genes in Escherichia coli Isolates from Hospital Wastewater in Vietnam. The environmental spread of antibiotic-resistant bacteria has been recognised as a growing public health threat for which hospitals play a significant role. The aims of this study were to investigate the prevalence of antibiotic resistance and antibiotic resistance genes (ARGs) in Escherichia coli isolates from hospital wastewater in Vietnam. Wastewater samples before and after treatment were collected using continuous sampling every month over a year. Standard disk diffusion and E-test were used for antibiotic susceptibility testing. Extended-spectrum beta-lactamase (ESBL) production was tested using combined disk diffusion. ARGs were detected by polymerase chain reactions. Resistance to at least one antibiotic was detected in 83% of isolates; multidrug resistance was found in 32%. The highest resistance prevalence was found for co-trimoxazole (70%) and the lowest for imipenem (1%). Forty-three percent of isolates were ESBL-producing, with the bla(TEM) gene being more common than bla(CTX-M). Co-harbouring of the bla(CTX-M), bla(TEM) and qepA genes was found in 46% of isolates resistant to ciprofloxacin. The large presence of antibiotic-resistant E. coli isolates combined with ARGs in hospital wastewater, even post-treatment, poses a threat to public health. It highlights the need to develop effective processes for hospital wastewater treatment plants to eliminate antibiotic resistant bacteria and ARGs.201728661465
194780.9998Search for carbapenem-resistant bacteria and carbapenem resistance genes along swine food chains in Central Italy. The presence of carbapenem-resistant bacteria and carbapenem resistance genes (CRGs) in livestock is increasing. To evaluate the presence of carbapenemase-producing Enterobacteriaceae (CPE) and the main CRGs along swine food chains of the Marche Region (Central Italy), samples of faeces, feed, and animal-food derived products were collected from seven small/medium, medium, and large-scale pig farms. A total of 191 samples were analysed using a culture-dependent method, with the aim of isolating CPE. Isolates were analysed for their resistance to carbapenems using a modified Hodge test and the microdilution method for the minimum inhibitory concentration (MIC) determination. Moreover, the extraction of microbial DNA from each sample was performed to directly detect selected CRGs via qPCR. Among the 164 presumptive resistant isolates, only one strain from a liver sample, identified as Aeromonas veronii, had an ertapenem MIC of 256 μg/mL and carried a carbapenemase- (cphA) and a β-lactamase- (blaOXA-12) encoding genes. A low incidence of CRGs was found; only nine and four faecal samples tested positive for blaNDM-1 and blaOXA-48, respectively. Overall, the importance of monitoring CPE and CRGs in livestock and their food chains should be stressed to control all potential non-human CPE and CRGs reservoirs and to determine safety levels for human health.202438181018
289390.9998Antibiotic-resistant bacteria associated with retail aquaculture products from Guangzhou, China. This study examined the prevalence of antibiotic-resistant (ART) bacteria and representative antibiotic resistance (AR)-encoding genes associated with several aquaculture products from retail markets in Guangzhou, China. ART commensal bacteria were found in 100% of the products examined. Among 505 multidrug-resistant isolates examined, close to one-fourth contained intI and sul1 genes: 15% contained sul2 and 5% contained tet (E). Incidences of β-lactamase-encoding genes bla(TEM), bla(CMY) and erythromycin resistance determinants ermB and ermC were 4.5, 1.7, 1.3, and 0.3%, respectively. Most of the ART isolates identified from the rinse water were Aeromonas spp.; those from intestines belonged to the Enterobacteriaceae. Plasmid-associated intI and AR-encoding genes were identified in several ART isolates by Southern hybridization. Three multidrug resistance-encoding plasmids were transferred into Escherichia coli DH5 a by chemical transformation and led to acquired AR in the transformants. In addition, the AR traits in many isolates were quite stable, even in the absence of selective pressure. Further studies are needed to reveal risk factors associated with the aquaculture production chain for targeted AR mitigation.201323433377
5314100.9998High prevalence of colistin resistance genes in German municipal wastewater. Bacterial resistance against the last-resort antibiotic colistin is of increasing concern on a global scale. Wastewater is suspected to be one of the pathways by which resistant bacteria and the respective genes are disseminated. We employed a metagenomics approach to detect and quantify colistin resistance genes in raw municipal wastewater sampled at 9 locations all over Germany (14 samples in total, collected in 2016/2017). Our data support the findings of earlier studies according to which the prevalence of the colistin resistance gene mcr-1 is still low. However, we were able to demonstrate that the total prevalence of colistin resistance genes is dramatically underestimated if the focus is put on that specific gene alone. In comparison to mcr-1, other gene variants like mcr-3 and mcr-7 proved to be 10 to 100 times more abundant in samples of untreated wastewater. The average relative abundances expressed as copies per 16S rRNA gene copies were 2.3×10(-3) for mcr-3, 2.2×10(-4) for mcr-4, 3.0×10(-4) for mcr-5, and 4.4×10(-4) for mcr-7. While these four gene variants were ubiquitous in all 14 samples, mcr-1 was detected only once at a relative abundance of 1.4×10(-5). Our results suggest a high risk of increasing incidence of colistin resistance as large amounts of mcr genes are continuously disseminated to diverse microbial communities via the wastewater path.201931398645
1709110.9998High prevalence of bla(VIM-1) gene in bacteria from Brazilian soil. This study investigated bacteria from soil samples to (i) determine the main bacterial genera and species having resistance to carbapenem and other β-lactams and (ii) establish if the mechanism of resistance was due to the production of metallo-β-lactamases. The isolates were characterized by PCR for metallo-β-lactamases and integrons, by antimicrobial susceptibility testing, and by sequencing. The antimicrobial profile of 40 imipenem-resistant Gram-positive soil isolates from all Brazilian regions demonstrated that 31 (77.5%) of them were multidrug resistant. Among the 40 isolates, 19 presented the bla(VIM) gene and class 1 integrons by PCR. Six of the 19 isolates were identified as Paenibacillus sp., 12 as Bacillus sp., and just 1 was classified as Staphylococcus sp., by sequencing of the 16S rRNA gene. These results suggest that bacteria from soil can act as a source of bla(VIM-1) genes, representing a threat to public health.201627392282
2043120.9998Antimicrobial Resistance Genotypes and Mobile Genetic Elements of Poultry-Derived Escherichia coli: A Retrospective Genomic Study from the United States. The presence of antibiotic resistance in commensal bacteria may be an influential factor in the persistence of resistance in pathogens. This is especially critical for Escherichia coli that consumers may be exposed to through the consumption of uncooked meat. In this study, E. coli isolates previously recovered from poultry in the US between 2001 and 2012 were whole-genome sequenced to identify their antibiotic resistance genes and mobile genetic elements. The genomes of 98 E. coli isolates from poultry carcass rinsates and 2 isolates from poultry diagnostic samples with multidrug resistance or potential extended-spectrum β-lactam (ESBL)-producing phenotypes as well as the genetic variabilities among the E. coli were assessed. All E. coli isolates were positive for at least one antibiotic resistance gene and plasmid replicon, with 37 resistance genes and 27 plasmid replicons detected among the isolates. While no ESBL genes were detected, bla(CMY-2) was the most common β-lactamase gene, and bla(TEM) and bla(CARB-2) were also identified. Most isolates (95%) harbored at least one intact phage, and as many as seven intact phages were identified in one isolate. These results show the occurrence of antibiotic resistance genes and mobile genetic elements in these 100 poultry-associated E. coli isolates, which may be responsible for the resistance phenotypes exhibited by the isolates. This retrospective study also enables comparisons of resistance genes and mobile genetic elements from more recent E. coli isolates associated with poultry to aid in understanding the trends of both antibiotic resistance phenotypes and genotypes in the poultry setting over time.202540872236
2731130.9998Prevalence of tetracycline resistance genes among multi-drug resistant bacteria from selected water distribution systems in southwestern Nigeria. BACKGROUND: Antibiotic resistance genes [ARGs] in aquatic systems have drawn increasing attention they could be transferred horizontally to pathogenic bacteria. Water treatment plants (WTPs) are intended to provide quality and widely available water to the local populace they serve. However, WTPs in developing countries may not be dependable for clean water and they could serve as points of dissemination for antibiotic resistant bacteria. Only a few studies have investigated the occurrence of ARGs among these bacteria including tetracycline resistance genes in water distribution systems in Nigeria. METHODOLOGY: Multi-drug resistant (MDR) bacteria, including resistance to tetracycline, were isolated from treated and untreated water distribution systems in southwest Nigeria. MDR bacteria were resistant to >3 classes of antibiotics based on break-point assays. Isolates were characterized using partial 16S rDNA sequencing and PCR assays for six tetracycline-resistance genes. Plasmid conjugation was evaluated using E. coli strain DH5α as the recipient strain. RESULTS: Out of the 105 bacteria, 85 (81 %) and 20 (19 %) were Gram- negative or Gram- positive, respectively. Twenty-nine isolates carried at least one of the targeted tetracycline resistance genes including strains of Aeromonas, Alcaligenes, Bacillus, Klebsiella, Leucobacter, Morganella, Proteus and a sequence matching a previously uncultured bacteria. Tet(A) was the most prevalent (16/29) followed by tet(E) (4/29) and tet30 (2/29). Tet(O) was not detected in any of the isolates. Tet(A) was mostly found with Alcaligenes strains (9/10) and a combination of more than one resistance gene was observed only amongst Alcaligenes strains [tet(A) + tet30 (2/10), tet(A) + tet(E) (3/10), tet(E) + tet(M) (1/10), tet(E) + tet30 (1/10)]. Tet(A) was transferred by conjugation for five Alcaligenes and two E. coli isolates. CONCLUSIONS: This study found a high prevalence of plasmid-encoded tet(A) among Alcaligenes isolates, raising the possibility that this strain could shuttle resistance plasmids to pathogenic bacteria.201526108344
2837140.9998Molecular evidence of the close relatedness of clinical, gull and wastewater isolates of quinolone-resistant Escherichia coli. Escherichia coli with reduced susceptibility to quinolones isolated from different environmental sources (urban wastewater treatment plants, n=61; hospital effluent, n=10; urban streams, n=9; gulls, n=18; birds of prey, n=17) and from hospitalised patients (n=28) were compared based on multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE). The habitats with the most diversified genotypes of quinolone-resistant E. coli, corresponding to the highest genetic diversity (H'), were wastewater and gulls. In addition, genetically distinct populations were observed in clinical samples and birds of prey, suggesting the influence of the habitat or selective pressures on quinolone-resistant E. coli. The close genetic relatedness between isolates of clinical origin and from gulls and wastewater suggests the existence of potential routes of propagation between these sources. The most common sequence types were ST131 and ST10, with ST131 being highly specific to patients, although distributed in all of the other habitats except birds of prey. The prevalence of antimicrobial resistance was significantly higher in isolates from patients and gulls than from other sources (P<0.01), suggesting that the effect of selective pressures met by isolates subjected to strong human impacts. The evidence presented suggests the potential circulation of bacteria between the environmental and clinical compartments, with gulls being a relevant vector of bacteria and resistance genes.201527842875
1965150.9998Phenotypic Investigation of Florfenicol Resistance and Molecular Detection of floR Gene in Canine and Feline MDR Enterobacterales. Florfenicol is a promising antibiotic for use in companion animals, especially as an alternative agent for infections caused by MDR bacteria. However, the emergence of resistant strains could hinder this potential. In this study, florfenicol resistance was investigated in a total of 246 MDR Enterobacterales obtained from canine and feline clinical samples in Greece over a two-year period (October 2020 to December 2022); a total of 44 (17,9%) florfenicol-resistant strains were recognized and further investigated. Most of these isolates originated from urine (41.9%) and soft tissue (37.2%) samples; E. coli (n = 14) and Enterobacter cloacae (n = 12) were the predominant species. The strains were examined for the presence of specific florfenicol-related resistance genes floR and cfr. In the majority of the isolates (31/44, 70.5%), the floR gene was detected, whereas none carried cfr. This finding creates concerns of co-acquisition of plasmid-mediated florfenicol-specific ARGs through horizontal transfer, along with several other resistance genes. The florfenicol resistance rates in MDR isolates seem relatively low but considerable for a second-line antibiotic; thus, in order to evaluate the potential of florfenicol to constitute an alternative antibiotic in companion animals, continuous monitoring of antibiotic resistance profiles is needed in order to investigate the distribution of florfenicol resistance under pressure of administration of commonly used agents.202438393089
2627160.9998High Prevalence of Drug Resistance and Class 1 Integrons in Escherichia coli Isolated From River Yamuna, India: A Serious Public Health Risk. Globally, urban water bodies have emerged as an environmental reservoir of antimicrobial resistance (AMR) genes because resistant bacteria residing here might easily disseminate these traits to other waterborne pathogens. In the present study, we have investigated the AMR phenotypes, prevalent plasmid-mediated AMR genes, and integrons in commensal strains of Escherichia coli, the predominant fecal indicator bacteria isolated from a major urban river of northern India Yamuna. The genetic environment of bla (CTX-M-15) was also investigated. Our results indicated that 57.5% of the E. coli strains were resistant to at least two antibiotic classes and 20% strains were multidrug resistant, i.e., resistant to three or more antibiotic classes. The multiple antibiotic resistance index of about one-third of the E. coli strains was quite high (>0.2), reflecting high contamination of river Yamuna with antibiotics. With regard to plasmid-mediated AMR genes, bla (TEM-1) was present in 95% of the strains, followed by qnrS1 and armA (17% each), bla (CTX-M-15) (15%), strA-strB (12%), and tetA (7%). Contrary to the earlier reports where bla (CTX-M-15) was mostly associated with pathogenic phylogroup B2, our study revealed that the CTX-M-15 type extended-spectrum β-lactamases (ESBLs) were present in the commensal phylogroups A and B1, also. The genetic organization of bla (CTX-M-15) was similar to that reported for E. coli, isolated from other parts of the world; and ISEcp1 was present upstream of bla (CTX-M-15). The integrons of classes 2 and 3 were absent, but class 1 integron gene intI1 was present in 75% of the isolates, denoting its high prevalence in E. coli of river Yamuna. These evidences indicate that due to high prevalence of plasmid-mediated AMR genes and intI1, commensal E. coli can become vehicles for widespread dissemination of AMR in the environment. Thus, regular surveillance and management of urban rivers is necessary to curtail the spread of AMR and associated health risks.202133633708
2734170.9998High Frequency of Antibiotic Resistance Genes (ARGs) in the Lerma River Basin, Mexico. The spread of beta-lactamase-producing bacteria is of great concern and the environment has been found to be a main source of contamination. Herein, it was proposed to determine the frequency of antimicrobial-resistant-Gram-negative bacteria throughout the Lerma River basin using phenotypic and molecular methods. Resistant bacteria were isolated with chromogenic media and antimicrobial susceptibility tests were used to characterize their resistance. ARGs for beta-lactams, aminoglycosides, and quinolones were detected by PCR. Species were identified by Sanger sequencing the 16S rRNA gene and the representative genomes of MDR strains were sequenced by NGS. A high variation in the number of isolates was observed in the 20 sampled sites, while observing a low diversity among the resistant bacteria. Of the 12 identified bacterial groups, C. freundii, E. coli, and S. marcescens were more predominant. A high frequency of resistance to beta-lactams, quinolones, and aminoglycosides was evidenced, where the bla(CTX,)qnrB, qnrS y, and aac(6')lb-cr genes were the most prevalent. C. freundii showed the highest frequency of MDR strains. Whole genome sequencing revealed that S. marcescens and K. pneumoniae showed a high number of shared virulence and antimicrobial resistance genes, while E. coli showed the highest number of unique genes. The contamination of the Lerma River with MDR strains carrying various ARGs should raise awareness among environmental authorities to assess the risks and regulations regarding the optimal hygienic and sanitary conditions for this important river that supports economic activities in the different communities in Mexico.202236360888
2622180.9998High rates of antimicrobial drug resistance gene acquisition after international travel, The Netherlands. We investigated the effect of international travel on the gut resistome of 122 healthy travelers from the Netherlands by using a targeted metagenomic approach. Our results confirm high acquisition rates of the extended-spectrum β-lactamase encoding gene blaCTX-M, documenting a rise in prevalence from 9.0% before travel to 33.6% after travel (p<0.001). The prevalence of quinolone resistance encoding genes qnrB and qnrS increased from 6.6% and 8.2% before travel to 36.9% and 55.7% after travel, respectively (both p<0.001). Travel to Southeast Asia and the Indian subcontinent was associated with the highest acquisition rates of qnrS and both blaCTX-M and qnrS, respectively. Investigation of the associations between the acquisitions of the blaCTX-M and qnr genes showed that acquisition of a blaCTX-M gene was not associated with that of a qnrB (p = 0.305) or qnrS (p = 0.080) gene. These findings support the increasing evidence that travelers contribute to the spread of antimicrobial drug resistance.201424655888
1900190.9998The dissemination of antimicrobial resistance determinants in surface water sources in Lebanon. The prevalence of antibiotic-resistant bacteria in surface water in Lebanon is a growing concern and understanding the mechanisms of the spread of resistance determinants is essential. We aimed at studying the occurrence of resistant bacteria and determinants in surface water sources in Lebanon and understanding their mobilization and transmission. Water samples were collected from five major rivers in Lebanon. A total of 91 isolates were recovered by incubating at 37°C on Blood and MacConkey agar out of which 25 were multi-drug resistant (MDR) and accordingly were further characterized. Escherichia coli and Klebsiella pneumoniae were the most common identified MDR isolates. Conjugation assays coupled with in silico plasmid analysis were performed and validated using PCR-based replicon typing (PBRT) to identify and confirm incompatibility groups and the localization of β-lactamase encoding genes. Escherichia coli EC23 carried a blaNDM-5 gene on a conjugative, multireplicon plasmid, while blaCTX-M-15 and blaTEM-1B were detected in the majority of the MDR isolates. Different sequence types (STs)were identified including the highly virulent E. coli ST131. Our results showed a common occurrence of bacterial contaminants in surface water and an increase in the risk for the dissemination of resistance determinants exacerbated with the ongoing intensified population mobility in Lebanon and the widespread lack of wastewater treatment.202134329434