Project description:Vibrio cholerae resistance to third-generation cephalosporins is rarely reported. We detected a strain that was negative for extended-spectrum β-lactamase and positive for the AmpC disk test, modified Hodge test, and EDTA disk synergy test and harbored the blaDHA-1 and blaNDM-1 genes. The antimicrobial drug susceptibility profile of V. cholerae should be monitored.
Project description:We report the persistent circulation of third-generation cephalosporin resistant Salmonella Typhi in Mumbai, linked to the acquisition and maintenance of a previously characterized IncX3 plasmid carrying the ESBL gene blaSHV-12 and the fluoroquinolone resistance gene qnrB7 in the genetic context of a triple mutant also associated with fluoroquinolone resistance.
Project description:Third-generation cephalosporin-resistant (3GC-R) Enterobacteriaceae represent a major threat to human health. Here, we captured 288 3GC-R Enterobacteriaceae clinical isolates from 264 patients presenting at a regional Australian hospital over a 14-month period. In addition to routine mass spectrometry and antibiotic sensitivity testing, isolates were examined using rapid (∼40-min) real-time PCR assays targeting the most common extended-spectrum β-lactamases (ESBLs; blaCTX-M-1 and blaCTX-M-9 groups, plus blaTEM, blaSHV, and an internal 16S rRNA gene control). AmpC CMY β-lactamase (blaCMY) prevalence was also examined. Escherichia coli (80.2%) and Klebsiella pneumoniae (17.0%) were dominant, with Klebsiella oxytoca, Klebsiella aerogenes, and Enterobacter cloacae infrequently identified. Ceftriaxone and cefoxitin resistance were identified in 97.0% and 24.5% of E. coli and K. pneumoniae isolates, respectively. Consistent with global findings in Enterobacteriaceae, most (98.3%) isolates harbored at least one β-lactamase gene, with 144 (50%) harboring blaCTX-M-1 group, 92 (31.9%) harboring blaCTX-M-9 group, 48 (16.7%) harboring blaSHV, 133 (46.2%) harboring blaTEM, and 34 (11.8%) harboring blaCMY genes. A subset of isolates (n = 98) were subjected to whole-genome sequencing (WGS) to identify the presence of cryptic resistance determinants and to verify genotyping accuracy. WGS of β-lactamase-negative or carbapenem-resistant isolates identified uncommon ESBL and carbapenemase genes, including blaNDM and blaIMP, and confirmed all PCR-positive genotypes. We demonstrate that our PCR assays enable the rapid and cost-effective identification of ESBLs in the hospital setting, which has important infection control and therapeutic implications.
Project description:The production of extended-spectrum ?-lactamases (ESBLs) conferring resistance to new derivatives of ?-lactams is a major public health threat if present in pathogenic Gram-negative bacteria. The objective of this study was to characterize ceftiofur (TIO)- or cefotaxime (FOX)-resistant Escherichia coli isolated from dairy cow manure. Twenty-four manure samples were collected from four farms and incubated under anaerobic conditions for 20 weeks at 4 °C or at 25 °C. A total of 37 TIO- or FOX-resistant E. coli were isolated from two of the four farms to determine their susceptibility to 14 antibiotics. Among the 37 resistant E. coli, 10 different serotypes were identified, with O8:H1 being the predominant serotype (n = 17). Five isolates belonged to each of serotypes O9:NM and O153:H42, respectively. All 37 cephalosporin resistant isolates were multi-resistant with the most prevalent resistance spectrum being amoxicillin-clavulanic acid-ampicillin-cefoxitin-ceftiofur-ceftriaxone-chloramphenicol-streptomycin-sulfisoxazole-tetracycline-trimethoprim-sulfamethoxazole. The genomes of 18 selected isolates were then sequenced and compared to 14 selected human pathogenic E. coli reference genomes obtained from public repositories using different bioinformatics approaches. As expected, all 18 sequenced isolates carried at least one ?-lactamase bla gene: TEM-1, TEM-81, CTX-M115, CTX-M15, OXA-1, or CMY-2. Several other antibiotic resistance genes (ARGs) and virulence determinants were detected in the sequenced isolates and all of them harbored antimicrobial resistance plasmids belonging to classic Inc groups. Our results confirm the presence of diverse ESBL producing E. coli isolates in dairy cow manure stored for a short period of time. Such manure might constitute a reservoir of resistance and virulence genes for other bacteria that share the same environment.
Project description:Here, we report the complete genome sequence of Comamonas kerstersii 3132976, a strain isolated from a human rectal swab sample in Switzerland. The isolate was resistant to third- and fourth-generation cephalosporins and possessed a novel class A β-lactamase gene. The complete genome is 3,693,404 bp long with a GC content of 59.4%.
Project description:Molecular ecology and risk factors for third-generation cephalosporin-resistant Escherichia coli carriage by dogs living in urban and nearby rural settings
Project description:The emergence of antimicrobial resistant (AMR) strains of Morganella morganii is increasingly being recognized. Recently, we reported a fatal M. morganii infection in a captive bottlenose dolphin (Tursiops truncatus) bred at a dolphinarium in South Korea. According to our subsequent investigations, the isolated M. morganii strain KC-Tt-01 exhibited extensive resistance to third-generation cephalosporins which have not been reported in animals. Therefore, in the present study, the genome of strain KC-Tt-01 was sequenced, and putative virulence and AMR genes were investigated. The strain had virulence and AMR genes similar to those of other M. morganii strains, including a strain that causes human sepsis. An amino-acid substitution detected at the 86th residue (Arg to Cys) of the protein encoded by ampR might explain the extended resistance to third-generation cephalosporins. These results indicate that the AMR M. morganii strain isolated from the captive dolphin has the potential to cause fatal zoonotic infections with antibiotic treatment failure due to extended drug resistance, and therefore, the management of antibiotic use and monitoring of the emergence of AMR bacteria are urgently needed in captive cetaceans for their health and conservation.
Project description:In human medicine, infections caused by third-generation cephalosporin-resistant Enterobacterales (3GCRE) are associated with detrimental outcomes. In veterinary medicine, controlled epidemiological analyses are lacking. A matched case-case-control investigation (1:1:1 ratio) was conducted in a large veterinary hospital (2017-2019). In total, 29 infected horses and donkeys were matched to 29 animals with third-generation cephalosporin-susceptible Enterobacterales (3GCSE) infections, and 29 uninfected controls (overall n = 87). Despite multiple significant associations per bivariable analyses, the only independent predictor for 3GCRE infection was recent exposure to antibiotics (adjusted odds ratio (aOR) = 104, p < 0.001), but this was also an independent predictor for 3GCSE infection (aOR = 22, p < 0.001), though the correlation with 3GCRE was significantly stronger (aOR = 9.3, p = 0.04). In separated multivariable outcome models, 3GCRE infections were independently associated with reduced clinical cure rates (aOR = 6.84, p = 0.003) and with 90 days mortality (aOR = 3.6, p = 0.003). Klebsiella spp. were the most common 3GCRE (36%), and blaCTX-M-1 was the major β-lactamase (79%). Polyclonality and multiple sequence types were evident among all Enterobacterales (e.g., Klebsiella pneumoniae, Escherichia coli, Enterobacter cloacae). The study substantiates the significance of 3GCRE infections in equine medicine, and their independent detrimental impact on cure rates and mortality. Multiple Enterobacterales genera, subtypes, clones and mechanisms of resistance are prevalent among horses and donkeys with 3GCRE infections.
Project description:ObjectivesEnterobacteriaceae are common pathogens causing bloodstream infection (BSI) in sub-Saharan Africa and frequently express third-generation cephalosporin (3GC) resistance; however, the impact of 3GC resistance on clinical outcomes is rarely studied.MethodsWe conducted a single-site prospective cohort study at Tygerberg Hospital, Cape Town, South Africa to examine the feasibility of measuring impacts of 3GC resistance in Enterobacteriaceae BSI. We included patients with 3GC-susceptible and 3GC-resistant BSIs and matched each BSI patient to two uninfected patients. We determined the concordance of initial antibiotic treatment with the corresponding isolate's susceptibility profile. We performed exploratory impact analysis using multivariable regression models.ResultsBetween 1 June 2017 and 31 January 2018, we matched 177 Enterobacteriaceae BSI patients to 347 uninfected patients. Among these BSIs, 35% were phenotypically 3GC resistant. Parameters describing clinical comorbidity showed strong associations with mortality. We found that 18% of 3GC-R and 3% of 3GC-S BSI patient received non-concordant initial therapy. In multivariable Cox regression, we found a mortality impact over their matched patients for both 3GC-R (cause-specific hazard ratio 23.77; 95% CI 5.12-110.3) and 3GC-S (HR 7.49; 95%CI 3.08-18.19) BSI. There was a nonsignificant ratio of these ratios (HR 3.18; 95% CI 0.54-18.70), limited by the small sample size.ConclusionThis form of impact estimation was feasible in one hospital in South Africa where 3GC-R status was associated with non-concordant initial antibiotic treatment. There was a possible increase in mortality among individuals with 3GC-resistant Enterobacteriaceae, but with broad confidence intervals. These analytical approaches could be applied to larger datasets to improve precision of estimates.
Project description:Antibiotic resistance (AR) remains one of the greatest threats to global health, and Aeromonas species have the potential to spread AR in the aquatic environment. The spread of resistance to antibiotics important to human health, such as third-generation cephalosporins (3GCs) and carbapenems, is of great concern. We isolated and identified 15 cefotaxime (3GC)- and 51 carbapenem-resistant Aeromonas spp. from untreated hospital and treated municipal wastewater in January 2020. The most common species were Aeromonas caviae (58%), A. hydrophila (17%), A. media (11%), and A. veronii (11%). Almost all isolates exhibited a multidrug-resistant phenotype and harboured a diverse plasmidome, with the plasmid replicons ColE, IncU, and IncR being the most frequently detected. The most prevalent carbapenemase gene was the plasmid-associated blaKPC-2 and, for the first time, the blaVIM-2, blaOXA-48, and blaIMP-13 genes were identified in Aeromonas spp. Among the 3GC-resistant isolates, the blaGES-5 and blaMOX genes were the most prevalent. Of the 10 isolates examined, three were capable of transferring carbapenem resistance to susceptible recipient E. coli. Our results suggest that conventionally treated municipal and untreated hospital wastewater is a reservoir for 3GC- and carbapenem-resistant, potentially harmful Aeromonas spp. that can be introduced into aquatic systems and pose a threat to both the environment and public health.