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135400.9967The prevalence, antibiotic resistance and multilocus sequence typing of colistin-resistant bacteria isolated from Penaeus vannamei farms in earthen ponds and HDPE film-lined ponds in China. The aquaculture environment, especially the culture ponds and aquaculture products, is considered to be an important reservoir of colistin resistance genes. However, systematic investigations of colistin resistance in Penaeus vannamei farming in different culture modes are scarce. In this study, a total of 93 non-duplicated samples were collected from P. vannamei farms in five cities in China from 2019 to 2021. The prevalence, antibiotic resistance and multilocus sequence typing (MLST) of colistin-resistant bacteria were measured and analysed. The results showed that among the 1601 isolates in P. vannamei and its environmental samples, the pollution of colistin-resistant bacteria was serious (the overall prevalence was 37.3% and 28.8%, respectively), regardless of the earthen pond or high-density polyethylene (HDPE) film-lined pond. Among 533 isolates, the prevalence of mobile colistin resistance (mcr) genes, mcr-1, was the highest (60%, 320/533), followed by mcr-4 (1.5%, 8/533), mcr-8 (0.9%, 5/533), mcr-10 (0.6%, 3/533) and mcr-7 (0.4%, 2/533). The prevalence of mcr-1 in earthen ponds was significantly higher than that in HDPE film-lined ponds (67.5% vs. 49.1%, p < .001). The dominant strain carrying mcr-1 was Bacillus spp. (54.1%, 173/320), followed by Enterobacter spp. (8.1%, 26/320), Staphylococcus spp. (6.3%, 20/320) and Aeromonas spp. (5.3%, 17/320). The antibiotic resistance profiles of 173 Bacillus spp. varied among different sampling locations and culture types. These isolates were highly resistant to cefepime, ceftriaxone, trimethoprim-sulfamethoxazole and ceftiofur (>45%), and multidrug-resistant isolates were common (62.4%, 108/173). Sequence type (ST) 26 (37/66, 56%) was found to be the most prevalent ST in mcr-1-positive Bacillus cereus isolated from the aquaculture environment. In summary, our study pointed out that it is necessary to continuously monitor antibiotic usage and its residues regardless of the pond types, especially with regard to critical drugs such as colistin.202235841601
129610.9966Prevalence and antimicrobial resistance of Salmonellaisolates from goose farms in Northeast China. BACKGROUND: Salmonella is one of the most important enteric pathogenic bacteria that threatened poultry health. AIMS: This study aimed to investigate the prevalence and antimicrobial resistance of Salmonella isolates in goose farms. METHODS: A total of 244 cloacal swabs were collected from goose farms to detect Salmonella in Northeast China. Antimicrobial susceptibility, and resistance gene distribution of Salmonella isolates were investigated. RESULTS: Twenty-one Salmonella isolates were identified. Overall prevalence of Salmonella in the present study was 8.6%. Among the Salmonella isolates, the highest resistance frequencies belonged to amoxicillin (AMX) (85.7%), tetracycline (TET) and trimethoprim/sulfamethoxazole (SXT) (81%), followed by chloramphenicol (CHL) (76.2%), florfenicol (FLO) (71.4%), kanamycin (KAN) (47.6%), and gentamycin (GEN) (38.1%). Meanwhile, only 4.8% of the isolates were resistant to ciprofloxacin (CIP) and cefotaxime (CTX). None of the isolates was resistant to cefoperazone (CFP) and colistin B (CLB). Twenty isolates (95%) were simultaneously resistant to at least two antimicrobials. Ten resistance genes were detected among which the bla (TEM-1), cmlA, aac(6')-Ib-cr, sul1, sul2, sul3, and mcr-1.1 were the most prevalent, and presented in all 21 isolates followed by tetB (20/21), qnrB (19/21), and floR (15/21). CONCLUSION: Results indicated that Salmonella isolates from goose farms in Northeast China exhibited multi-drug resistance (MDR), harboring multiple antimicrobial resistance genes. Our results will be useful to design prevention and therapeutic strategies against Salmonella infection in goose farms.202033584841
527420.9966Presence of heavy metal resistance genes in Escherichia coli and Salmonella isolates and analysis of resistance gene structure in E. coli E308. OBJECTIVES: With the wide use of heavy metals as feed additives in animal production, little attention has been paid to heavy metal resistance in pathogenic bacteria. This study was performed to investigate the presence of heavy metal resistance genes (HMRGs) in Escherichia coli and Salmonella isolates and its correlation with disinfectant resistance genes (DRGs) and antibiotic resistance genes (ARGs). METHODS: HMRGs of 178 E. coli and 294 Salmonella isolated from chicken broiler farms and retail meat were detected by PCR. Minimum inhibitory concentrations (MICs) of heavy metals were determined by the broth microdilution method. The complete genome of E. coli E308, which had indications of multidrug resistance, was recovered and assembled using third-generation sequencing. RESULTS: The frequency of different HMRGs in E. coli and Salmonella ranged from 0.60-77.0% and 0.30-87.1%, respectively. MICs of heavy metals for E. coli and Salmonella ranged widely from ≤12.5 mg/L to 1600 mg/L. Moreover, HMRGs (zntA, arsB, merA, pcoR, pcoA, pcoC and chrA) were found to be significantly associated with one or more DRGs [sugE(c), emrE, mdfA, ydgE/ydgF, qacF, sugE(p) and qacEΔ1] and ARGs (sul1, sul2, sul3, tetA, tetB, tetC, bla(TEM), bla(SHV) and bla(CTX)) (P < 0.05). CONCLUSION: This study demonstrated that HMRGs are widely present in E. coli and Salmonella isolated from chicken farms and retail meat. The association between HMRGs with DRGs and ARGs may lead to co-resistance to heavy metals and other antimicrobial agents.202032006752
131930.9966Isolation and Identification of Aerobic Bacteria Carrying Tetracycline and Sulfonamide Resistance Genes Obtained from a Meat Processing Plant. Microbial contamination in food-processing plants can play a fundamental role in food quality and safety. The purpose of this study was to investigate aerobic bacteria carrying tetracycline and sulfonamide resistance genes from a meat processing plant as possible sources of meat contamination. One hundred swab samples from surfaces of conveyor belts, meat slicers, meat knives, benches, plastic trays, gloves, and aprons were analyzed. A total of 168 isolates belonging to 10 genera were obtained, including Pseudomonas sp. (n = 35), Acinetobacter sp. (n = 30), Aeromonas sp. (n = 20), Myroides sp. (n = 15), Serratia sp. (n = 15), Staphylococcus sp. (n = 14), Enterobacter sp. (n = 11), Escherichia coli (n = 10), Lactococcus sp. (n = 10), and Klebsiella sp. (n = 8). Of the 168 isolates investigated, 60.7% showed resistance to tetracycline and 57.7% to trimethoprim/sulfamethoxazole. The tetracycline resistance genes tetL, tetA, tetB, tetC, tetE, tetM, tetS, tetK, and tetX were found in the frequency of 7.7%, 6.0%, 4.8%, 4.8%, 3.6%, 3.6%, 3.6%, 1.2%, and 0.6%, respectively. Sulfonamide resistance genes sul1 and sul2 were observed in the frequency of 17.9% and 38.1%, respectively. The tetracycline resistance genes tetX was first found in Myroides sp. This investigation demonstrated that food contact surfaces in a meat processing plant may be sources of contamination of aerobic bacteria carrying tetracycline and sulfonamide antibiotic resistance genes.201627100915
129140.9965Occurrence of potentially zoonotic and cephalosporin resistant enteric bacteria among shelter dogs in the Central and South-Central Appalachia. BACKGROUND: Antimicrobial resistance and presence of zoonotic enteropathogens in shelter dogs pose a public health risk to shelter workers and potential adopters alike. In this study we investigated the prevalence of zoonotic bacterial pathogens and cephalosporin resistant (Cef(R)) enteric bacteria in the feces of apparently healthy shelter dogs in the Cumberland Gap Region (CGR) in the US states of Kentucky, Tennessee and Virginia. RESULTS: Fecal samples of 59 dogs from 10 shelters in the CGR of Central and South-Central Appalachia were screened for the presence of Campylobacter jejuni, Clostridium perfringens, Salmonella and Cef(R) enteric bacteria. C. jejuni, C. perfringens were detected by PCR based assays. Culture and PCR were used for Salmonella detection. Of 59 dogs, fecal samples from 14 (23.7%) and 8 (13.6%) dogs tested positive for cpa and hipO genes of C. perfringens and C. jejuni, respectively. Salmonella was not detected in any of the tested samples by PCR or culture. Cef(R) enteric bacteria were isolated on MacConkey agar supplemented with ceftiofur followed by identification using MALDI-TOF. Fecal samples from 16 dogs (27.1%) yielded a total of 18 Cef(R) enteric bacteria. Majority of Cef(R) isolates (14/18, 77.8%) were E. coli followed by, one isolate each of Enterococcus hirae, Acinetobacter baumannii, Acinetobacter pittii, and Pseudomonas aeruginosa. Cef(R) enteric bacteria were tested for resistance against 19- or 24-antibiotic panels using broth microdilution method. Seventeen (94.4%) Cef(R) bacteria were resistant to more than one antimicrobial agent, and 14 (77.8%) displayed multidrug resistance (MDR). CONCLUSIONS: This study shows that shelter dogs within the CGR not only carry zoonotic bacterial pathogens, but also shed multidrug resistant enteric bacteria in their feces that may pose public health risks.202134563197
97250.9965Prevalence of antimicrobial resistance and integron gene cassettes in Escherichia coli isolated from yaks (Poephagus grunniens) in Aba Tibetan Autonomous Prefecture, China. BACKGROUND: Escherichia coli (E. coli) is one of the most relevant opportunistic pathogenic bacteria as it may cause severe morbidity and mortality in yaks (poephagus grunniens). In recent years, several kinds of antibiotics have been widely used in Tibetan areas to treat the bacterial diseases, resulting in serious repercussions on the bacterial antibiotic resistance in yaks. This investigation was conducted in order to determine the prevalence of antimicrobial resistance and integron gene cassettes in E. coli isolated from yaks in Aba Tibetan Autonomous Prefecture (Aba TAP), China. METHODS: A total of 278 non-duplicated fresh samples were collected from the yaks in Aba TAP for the isolation and identification of E. coli isolates. Antimicrobial susceptibility testing is performed by using the disc diffusion method according to the Clinical and Laboratory Standards Institute guidelines (CLSI, 2013). Various antibiotic resistance genes and integron gene cassettes were detected by polymerase chain reaction (PCR) and sequencing. RESULTS: Overall, a total of 228 E. coli bacteria were isolated from the fresh faeces of yaks in four different geographical regions. 58% of those isolates showed multi-drug resistance capabilities (MDR) in our study. These isolated bacteria showed a high resistance rate to streptomycin (84%), cefotaxime (79%), amikacin (61%) and trimethoprim-sulfamethoxazole (54%). The most common antimicrobial resistance genes in the isolates were bla(CTX-M), sul1, aph (3')-IIa, aac (3)-IIa, aac (6')-Ib, tetB, with respective detection rates of 65%, 46%, 35%, 13%, 11%, and 10%. Furthermore, 66% and 6% of the strains carried Class 1 and 2 integrons, respectively. However, the class 3 integron was not detected. Gene cassette arrays in the class 1 integron included aadA1, aadA7, aadA5, aadA17, dfrA1, dfrA5, dfrA1-aadA1, dfrA12-aadA2 and dfrA17-aadA5. The most prevalent gene cassette was aadA1 (20%). For the class 2 integron, dfrA1-sat2-aadA1 (6%) and dfrA1-sat1-aadA1 (0.4%) were also detected as part of this research. CONCLUSION: High multi-drug resistance rates have been discovered, as well as a prevalence of antibiotic resistance genes and integron gene cassettes in the E. coli isolated from the faeces of yak. This might create a potential problem for treatment of the yaks' bacterial infections as well as food hygiene for humans. It is therefore urgently necessary to begin continuous surveillance and analysis of antibiotic resistance and integron cassettes in other bacteria from yaks.201728888884
115460.9965Migratory wild birds carrying multidrug-resistant Escherichia coli as potential transmitters of antimicrobial resistance in China. Migratory birds play an important role in the spread of multidrug-resistant (MDR) bacteria. To investigate the prevalence of MDR Escherichia coli in migratory birds in China and potential relationships with the environment, a total of 1387 samples (fecal samples, cloacal swabs, or throat swabs) were collected from migratory birds from three different river basins in China. The collected samples were processed and subjected to bacteriological examinations. Antimicrobial susceptibility testing of the recovered isolates was performed using the E-test for the detection of minimum inhibitory concentrations (MICs). Some antibiotic resistance genes were detected and the PCR products were confirmed by sequencing. In total, 478 (34.7%) E. coli isolates were recovered. The results showed that the drug-resistant E. coli isolates were highly resistant to β-lactams (43.7%) and tetracycline (22.6%), and 73 (15.3%) were MDR, including eight that were extended spectrum β-lactamase-positive. The retrieved strains harbored the blaCTX-M, blaTEM-1, tet(A), tet(B), tet(M), sul1, sul2, sul3, cmlA, floR, and intI1 genes with a prevalence of 5.9%, 36.4%, 80.5%, 11.9%, 6.8%, 6.8%, 47.5%, 12.7%, 50.8%, 37.3%, and 61.0%, respectively. The drug resistance rate of the isolates from southern China was higher than those from northern China. The E. coli samples collected for migratory birds in the Pearl River Basin had the highest proportion (46.7%) MDR isolates. Furthermore, MDR bacteria carried by migratory birds were closely related to the antibiotic content in the basin, which confirms that MDR bacteria carried by migratory birds are likely acquired from the environment. This study also confirmed that migratory birds are potential transmitters of MDR bacteria, demonstrating the need to reduce the use and emission of antibiotics and further in-depth studies on the mechanisms underlying drug resistance of bacteria.202134910771
83470.9965Molecular diversity of class 2 integrons in antibiotic-resistant gram-negative bacteria found in wastewater environments in China. The molecular architecture of class 2 integrons among gram-negative bacteria from wastewater environments was investigated in Jinan, China. Out of the 391 antibiotic-resistant bacteria found, 38 isolates harboring class 2 integrons encoding potentially transferrable genes that could confer antibiotic resistance were found. These isolates were classified into 19 REP-PCR types. These strains were identified using 16S rRNA gene sequencing and found to be as follows: Proteus mirabilis (16), Escherichia coli (7), Providencia spp. (7), Proteus spp. (2), P. vulgaris (3), Shigella sp. (1), Citrobacter freundii (1), and Acinetobacter sp. (1). Their class 2 integron cassette arrays were amplified and then either analyzed using PCR-RFLP or sequenced. The typical array dfrA1-sat2-aadA1 was detected in 27 isolates. Six atypical arrays were observed, including three kinds of novel arrangements (linF2(∆attC1)-dfrA1(∆attC2)-aadA1-orf441 or linF2(∆attC1)-dfrA1(∆attC2)-aadA1, dfrA1-catB2-sat2-aadA1, and estX(Vr)-sat2-aadA1) and a hybrid with the 3'CS of class 1 integrons (dfrA1-sat2-aadA1-qacH), and dfrA1-sat1. Twenty-four isolates were also found to carry class 1 integrons with 10 types of gene cassette arrays. Several non-integron-associated antibiotic resistance genes were found, and their transferability was investigated. Results showed that water sources in the Jinan region harbored a diverse community of both typical and atypical class 2 integrons, raising concerns about the overuse of antibiotics and their careless disposal into the environment.201323264021
117280.9965The prevalence and mechanism of fluoroquinolone resistance in Escherichia coli isolated from swine farms in China. BACKGROUND: It has been demonstrated that swine waste is an important reservoir for resistant genes. Moreover, the bacteria carrying resistant genes and originating from swine feces and wastewater could spread to the external environment. Fluoroquinolones (FQs) are widely used in livestock and poultry for the treatment of bacterial infection. However, resistance to FQs has increased markedly. RESULTS: In this study, swine feces and wastewater were sampled from 21 swine farms of seven provinces in China to investigate the prevalence of FQ resistance, including plasmid-mediated fluoroquinolone resistance (PMQR) genes and the occurrence of target mutations. All isolates showed moderate rate of resistance to norfloxacin (43.0%), ciprofloxacin (47.6%), ofloxacin (47.0%) and levofloxacin (38.8%). The percentage of strains resistant to the four FQs antimicrobials was positively correlated with the danofloxacin (DANO) MIC. Among the 74 FQ-resistant isolates, 39 (52.70%) had mutations in gyrA (S83L and D87 to N, Y, G, or H), 21 (28.38%) had mutations in parC (S80I and E84K), 2 (2.70%) had mutations in parE (I355T and L416F), 26 (35.14%) had mutations in marR (D67N and G103S), 1 (1.35%) had mutations in acrR (V29G). While, no mutation was found in gyrB. There were 7 (9.46%) strains carried the qnrS gene, 29 (39.19%) strains carried the oqxAB gene, and 9 (12.16%) strains carried the aac (6')-Ib-cr gene. In addition, the conjugation assays showed that qnrS, oqxAB and aac (6')-Ib-cr could be successfully transferred to E. coli J53 from 4 (57.1%), 20 (69.0%) and 5 (55.6%) donor strains, respectively. There were no qnrA, qnrB, qnrC, qnrD and qepA genes detected. CONCLUSION: The present study showed that DANO-resistant E. coli strains isolated from swine farms had significant cross-resistance to other four FQs antimicrobials. Further study revealed that the resistance mechanisms of swine-derived E. coli to FQs may be attributable to the occurrence of chromosomal mutations (gyrA, parC, parE, marR and acrR genes double-site or single-site mutation) and the presence of PMQR genes (qnrS, oqxAB and aac (6')-Ib-cr). To the best of our knowledge, one novel mutation marR-D67N was found to be associated with FQ resistance, two mutations parE-L416F and acrR-V29G have never been reported in China.202032723358
233090.9965Antimicrobial and disinfectant resistance of Escherichia coli isolated from giant pandas. AIMS: The study aims to demonstrate the antimicrobial and disinfectant resistance phenotypes and genotypes of Escherichia coli isolates obtained from giant pandas (Ailuropoda melanoleuca). METHODS AND RESULTS: Antimicrobial testing was performed according to the standard disk diffusion method. The minimal inhibitory concentrations (MICs) of disinfectants were determined using the agar dilution method. All isolates were screened for the presence of antimicrobial and disinfectant resistance genes and further analysed for genetic relatedness by pulse-field gel electrophoresis (PFGE). Results showed that 46·6% of the isolates were resistant to at least one antimicrobial. Escherichia coli isolates showed resistance to fewer antimicrobials as panda age increased. Among antimicrobial-resistant E. coli isolates, the antimicrobial resistance genes blaCTX-M (88·2%) and sul1 (92·3%) were most prevalent. The disinfectant resistance genes emrE, ydgE/ydgF, mdfA and sugE(c) were commonly present (68·2-98·9%), whereas qac and sugE(p) were relatively less prevalent (0-21·3%). The frequencies of resistance genes tended to be higher in E. coli isolated in December than in July, and PFGE profiles were also more diverse in isolates in December. The qacEΔ1 and sugE(p) genes were higher in adolescent pandas than in any other age groups. PFGE revealed that antimicrobial resistance correlated well with sampling time and habitat. CONCLUSIONS: This study demonstrated that antimicrobial and disinfectant resistance was common in giant panda-derived E. coli, and the antimicrobial resistance was associated with sampling time and habitat. Escherichia coli could serve as a critical vector in spreading disinfectant and antimicrobial resistance. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first study that demonstrated the phenotypic and genetic characterizations of antimicrobial and disinfectant resistance in E. coli isolates from more than 60 giant pandas. Frequent transfer of pandas to other cages may lead to the dissemination of antimicrobial resistance. The study highlights the need for regularly monitoring the antimicrobial and disinfectant resistance in bacteria from giant pandas.201525846200
2941100.9964Uncovering hidden threats: prevalence, antibiotic resistance and virulence gene profiles of Escherichia coli strains isolated from Testudines and their aquatic habitats. BACKGROUND: The gut microbiota of Testudines is fundamental to their digestion and overall health, yet remains a poorly investigated area in their biology, particularly in wild freshwater turtle (terrapins) and tortoise populations within South Africa. This study investigated the occurrence, diversity, virulence genes and antibiotic resistance of Escherichia coli isolated from Testudine gut microbiota and sediments at Timbavati Private Nature Reserve, South Africa. METHODS AND RESULTS: Cloacal swab samples were collected from 36 wild Testudines and 20 sediment samples from temporary and permanent water bodies. Presumed E. coli isolates were confirmed by polymerase chain reaction (PCR) targeting the β-D glucuronidase (uidA) gene and further validated through 16 S rRNA gene sequencing. Phenotypic antibiotic resistance was evaluated with the Kirby-Bauer method, whilst resistance and virulence genes were identified using PCR assays. E. coli was detected in 54 (62%) of 87 isolates (23 Testudines and 31 sediments), confirmed by uidA PCR assay. Detected virulence genes included eaeA (42%), virF (22%), stx1 (16%), and stx2 (3%), and isolates exhibited resistance to erythromycin (53%), cephalothin (48%), and spectinomycin (40%). Resistance genes such as mcr-4 (70%), bla(SHV) (46%), bla(TEM) (64%), mcr-1 (42%), qnrA (16%), mcr-2 (22%), qnrD (11%), and tetW (2%) were also detected. CONCLUSIONS: This study demonstrates that wild Testudines harbour E. coli in their gut and that it also occurs in their surrounding environment, with notable antibiotic resistance and virulence potential. The findings underscore the complexity of host-microbial interactions and the influence of environmental and host factors on microbial diversity, informing potential conservation and health management strategies for these reptilian species.202540751752
5432110.9964First large-scale study of antimicrobial susceptibility data, and genetic resistance determinants, in Fusobacterium necrophorum highlighting the importance of continuing focused susceptibility trend surveillance. OBJECTIVES: The objective of the study was to explore antimicrobial resistance gene determinant, and phenotypic antibiotic susceptibility, data for Fusobacterium necrophorum from a collection of UK strains. Antimicrobial resistance genes detected in publicly available assembled whole genome sequences were investigated for comparison. METHODS: Three hundred and eighty five F. necrophorum strains (1982-2019) were revived from cryovials (Prolab). Subsequent to sequencing (Illumina) and quality checking, 374 whole genomes were available for analysis. Genomes were interrogated, using BioNumerics (bioMérieux; v 8.1), for the presence of known antimicrobial resistance genes (ARGs). Agar dilution susceptibility results for 313 F. necrophorum isolates (2016-2021) were also examined. RESULTS: The phenotypic data for the 313 contemporary strains demonstrated potential resistance to penicillin in three isolates, using EUCAST v 11.0 breakpoints, and 73 (23%) strains using v 13.0 analysis. All strains were susceptible to multiple agents using v 11.0 guidance other than clindamycin (n = 2). Employing v 13.0 breakpoints, metronidazole (n = 3) and meropenem (n = 13) resistance were also detected. The tet(O), tet(M), tet(40), aph(3')-III, ant(6)-la and bla(OXA-85) ARGs were present in publicly available genomes. tet(M), tet(32), erm(A) and erm(B) were found within the UK strains, with correspondingly raised clindamycin and tetracycline minimum inhibitory concentrations. CONCLUSIONS: Susceptibility to antibiotics recommended for the treatment of F. necrophorum infections should not be assumed. With evidence of potential ARG transmission from oral bacteria, and the detection of a transposon-mediated beta-lactamase resistance determinant in F. necrophorum, surveillance of both phenotypic and genotypic antimicrobial susceptibility trends must continue, and increase.202336871786
1295120.9964Phenotypic and genotypic characterisation of antimicrobial resistance in faecal bacteria from 30 Giant pandas. To study the prevalence of antimicrobial resistance in faecal bacteria from Giant pandas in China, 59 isolates were recovered from faecal pats of 30 Giant pandas. Antimicrobial susceptibility testing of the isolates was performed by the standardised disk diffusion method (Kirby-Bauer). Of the 59 study isolates, 32.20% were resistant to at least one antimicrobial and 16.95% showed multidrug-resistant phenotypes. Thirteen drug resistance genes [aph(3')-IIa, aac(6')-Ib, ant(3'')-Ia, aac(3)-IIa, sul1, sul2, sul3, tetA, tetC, tetM, cat1, floR and cmlA] were analysed using four primer sets by multiplex polymerase chain reaction (PCR). The detection frequency of the aph(3')-IIa gene was the highest (10.17%), followed by cmlA (8.47%). The genes aac(6')-Ib, sul2 and tetA were not detected. PCR products were confirmed by DNA sequence analysis. The results revealed that multidrug resistance was widely present in bacteria isolated from Giant pandas.200919168331
2182130.9964Antibiotic resistance and virulence profiles of Proteus mirabilis isolated from broiler chickens at abattoir in South Africa. BACKGROUND: Proteus mirabilis has been identified as an important zoonotic pathogen, causing several illnesses such as diarrhoea, keratitis and urinary tract infections. OBJECTIVE: This study assessed the prevalence of P. mirabilis in broiler chickens, its antibiotic resistance (AR) patterns, ESBL-producing P. mirabilis and the presence of virulence genes. METHODS: A total of 26 isolates were confirmed as P. mirabilis from 480 pooled broiler chicken faecal samples by polymerase chain reaction (PCR). The disk diffusion method was used to evaluate the antibacterial susceptibility test, while nine virulence genes and 26 AR genes were also screened by PCR. RESULTS: All 26 P. mirabilis isolates harboured the ireA (siderophore receptors), ptA, and zapA (proteases), ucaA, pmfA, atfA, and mrpA (fimbriae), hlyA and hpmA (haemolysins) virulence genes. The P. mirabilis isolates were resistant to ciprofloxacin (62%) and levofloxacin (54%), while 8 (30.7%) of the isolates were classified as multidrug resistant (MDR). PCR analysis identified the bla(CTX-M) gene (62%), bla(TEM) (58%) and bla(CTX-M-2) (38%). Further screening for AMR genes identified mcr-1, cat1, cat2, qnrA, qnrD and mecA, 12%, 19%, 12%, 54%, 27% and 8%, respectively for P. mirabilis isolates. The prevalence of the integron integrase intI1 and intI2 genes was 43% and 4%, respectively. CONCLUSIONS: The rise of ciprofloxacin and levofloxacin resistance, as well as MDR strains, is a public health threat that points to a challenge in the treatment of infections caused by these zoonotic bacteria. Furthermore, because ESBL-producing P. mirabilis has the potential to spread to humans, the presence of bla(CTX) (-M) -producing P. mirabilis in broilers should be kept under control. This is the first study undertaken to isolate P. mirabilis from chicken faecal samples and investigate its antibiotic resistance status as well as virulence profiles in South Africa.202438357843
2951140.9964The diversity in antimicrobial resistance of MDR Enterobacteriaceae among Chinese broiler and laying farms and two mcr-1 positive plasmids revealed their resistance-transmission risk. This research aimed to investigate the microbial composition and diversity of antimicrobial resistance genes (ARGs) found in Chinese broiler and layer family poultry farms. We focused on the differences in resistance phenotypes and genotypes of multidrug-resistant Enterobacteriaceae (MDRE) isolated from the two farming environments and the existence and transmissibility of colistin resistance gene mcr-1. Metagenomic analysis showed that Firmicutes and Bacteroides were the dominant bacteria in broiler and layer farms. Many aminoglycoside and tetracycline resistance genes were accumulated in these environments, and their absolute abundance was higher in broiler than in layer farms. A total of 526 MDRE were isolated with a similar distribution in both farms. The results of the K-B test showed that the resistance rate to seven antimicrobials including polymyxin B and meropenem in broiler poultry farms was significantly higher than that in layer poultry farms (P ≤ 0.05). PCR screening results revealed that the detection rates of mcr-1, aph(3')Ia, aadA2, bla (oxa-1) , bla (CTX-M) , fosB, qnrD, sul1, tetA, and catA1 in broiler source MDRE were significantly higher than those in layers (P ≤0.05). A chimeric plasmid p20432-mcr which carried the novel integron In1866 was isolated from broiler source MDRE. The high frequency of conjugation (10(-1) to 10(-3)) and a wide range of hosts made p20432-mcr likely to play an essential role in the high detection rate of mcr-1, aph(3')-Ia, and aadA2 in broiler farms. These findings will help optimize disinfection and improve antimicrobial-resistant bacteria surveillance programs in poultry farms, especially broilers.202235992687
1278150.9964Multidrug-resistant enterococci in the hospital environment: detection of novel vancomycin-resistant E. faecium clone ST910. INTRODUCTION: The role of the hospital environment as a reservoir of resistant bacteria in Tunisia has been poorly investigated; however, it could be responsible for the transmission of multidrug-resistant bacteria. The objective was to study the prevalence of Enterococcus in the environment of a Tunisian hospital and the antibiotic resistance phenotype/genotype in recovered isolates, with special reference to vancomycin resistance. METHODOLOGY: A total of 300 samples were taken (March-June, 2013) and inoculated in Slanetz-Bartley agar plates supplemented or not supplemented with 8 µg/mL of vancomycin. Antibiotic resistance genes were tested by polymerase chain reaction (PCR). The clonal relatedness of the vanA isolates was assessed using pulsed-field gel electrophoresis (PFGE) and multilocus sequence testing (MLST). RESULTS: Enterococci were recovered in 33.3% of tested samples inoculated in SB medium. E faecium was the most prevalent species, followed by E. faecalis and E. casseliflavus. Antimicrobial resistance genes detected were as follows (number of isolates): erm(B) (71), tet(M) (18), aph(3')-IIIa (27), ant(6)-Ia (15), cat(A) (4), and van(C2) (6). Vancomycin-resistant-enterococci (VRE) were recovered from 14 samples (4.7%), when tested in SB-VAN. The 14 VRE (one per positive sample) were identified as E. faecium and contained the van(A),erm(B), tet(M), ant(6)-Ia, and aph(3')-IIIa genes. Thirteen of the VRE strains were ascribed by PFGE and MLST to a novel clone (new ST910), and only one VRE strain was typed as ST80 included in CC17. CONCLUSIONS: The emergence and spread of new clones of VRE, especially in the hospital environment in this country, could become particularly problematic.201627580324
1328160.9964Analysis of Resistance to Macrolide-Lincosamide-Streptogramin B Among mecA-Positive Staphylococcus Aureus Isolates. OBJECTIVES: Genetic determinants conferring resistance to macrolide, lincosamide, and streptogramin B (MLS(B)) via ribosomal modification such as, erm, msrA/B and ereA/B genes are distributed in bacteria. The main goals of this work were to evaluate the dissemination of MLS(B) resistance phenotypes and genotypes in methicillin-resistant Staphylococcus aureus (MRSA) isolates collected from clinical samples. METHODS: A total of 106 MRSA isolates were studied. Isolates were recovered from 3 hospitals in Tehran between May 2016 to July 2017. The prevalence of MLS(B)-resistant strains were determined by D-test, and then M-PCR was performed to identify genes encoding resistance to macrolides, lincosamides, and streptogramins in the tested isolates. RESULTS: The frequency of constitutive resistance MLS(B), inducible resistance MLS(B) and MS(B) resistance were 56.2%, 22.9%, and 16.6%, respectively. Of 11 isolates with the inducible resistance MLS(B) phenotype, ermC, ermB, ermA and ereA were positive in 81.8%, 63.6%, 54.5% and 18.2% of these isolates, respectively. In isolates with the constitutive resistance MLS(B) phenotype, the prevalence of ermA, ermB, ermC, msrA, msrB, ereA and ereB were 25.9%, 18.5%, 44.4%, 0.0%, 0.0%, 11.1% and 0.0%, respectively. CONCLUSION: Clindamycin is commonly administered in severe MRSA infections depending upon the antimicrobial susceptibility findings. This study showed that the D-test should be used as an obligatory method in routine disk diffusion assay to detect inducible clindamycin resistance in MRSA so that effective antibiotic treatment can be provided.201930847268
1147170.9964Detection and Characterisation of Colistin-Resistant Escherichia coli in Broiler Meats. The irrational use of antimicrobials has led to the emergence of resistance, impacting not only pathogenic bacteria but also commensal bacteria. Resistance against colistin, a last-resort antibiotic, mediated by globally disseminated plasmid-borne mobile colistin resistance (mcr) genes, has raised significant global concerns. This cross-sectional study aimed to investigate the antimicrobial resistance patterns of colistin-resistant Escherichia coli (E. coli) and mobilised colistin resistance (mcr 1-5) genes from broiler meat. A total of 570 broiler samples (285 liver and 285 muscle) were collected from 7 supermarkets and 11 live bird markets (LBMs) in Chattogram metropolitan areas of Bangladesh. The isolation and identification of E. coli were carried out using standard bacteriological and molecular techniques. Antimicrobial susceptibility testing (AST) was performed using the Kirby-Bauer disc diffusion method, and colistin's minimum inhibitory concentration (MIC) was determined by the broth microdilution (BMD) method. Colistin-resistant isolates were further tested for the presence of mcr (1-5) genes using polymerase chain reaction (PCR). Out of the 570 samples, 311 (54.56%; 95% confidence interval: 50.46-58.60) were positive for E. coli. AST results showed the highest resistance to sulphamethoxazole-trimethoprim (89.39%), while the highest susceptibility was observed for cefalexin (62.70%). A total of 296 isolates (95.18%) were found to be multidrug-resistant (MDR), with the multiple antibiotic resistance (MAR) index ranging from 0.38 to 1. Additionally, 41 isolates (13.18%) exhibited resistance to five antimicrobial classes, with resistance patterns of CIP + SXT + AMP + DO + TE + CT. A total of 233 isolates (74.92%) were resistant to colistin (MIC > 2 mg/L). A strong correlation between colistin resistance and the presence of the mcr-1 gene was observed (r = 1). All phenotypic colistin-resistant E. coli isolates carried the mcr-1 gene, while no isolates were positive for mcr (2-5). The detection of mcr genes in E. coli strains from poultry sources poses a significant risk, as these resistance genes can be transferred to humans through the food chain. The prevalence of multidrug-resistant Escherichia coli and the mcr-1 gene in poultry products in Bangladesh presents a significant public health and food safety concern.202439770738
1358180.9964Dissemination of Trimethoprim-Sulfamethoxazole Drug Resistance Genes Associated with Class 1 and Class 2 Integrons Among Gram-Negative Bacteria from HIV Patients in South India. The antibiotic, trimethoprim-sulfamethoxazole (TMP-SMX), is generally used for prophylaxis in HIV individuals to protect them from Pneumocystis jiroveci infection. Long-term use of TMP-SMX develops drug resistance among bacteria in HIV patients. The study was aimed to detect the TMP-SMX resistance genes among gram-negative bacteria from HIV patients. TMP-SMX-resistant isolates were detected by the Kirby-Bauer disc diffusion method. While TMP resistance genes such as dfrA1, dfrA5, dfrA7, and dfrA17 and SMX resistance genes such as sul1 and sul2 were detected by multiplex PCR, class 1 and class 2 integrons were detected by standard monoplex PCR. Of the 151 TMP-SMX-resistant bacterial isolates, 3 were positive for sul1 alone, 48 for sul2 alone, 11 for dfrA7 alone, 21 for sul1 and sul2, 1 for sul1 and dfrA7, 23 for sul2 and dfrA7, 2 for sul2 and dfrA5, 41 for sul1, sul2, and dfrA7, and 1 for sul2, dfrA5, and dfrA7. Of 60 TMP-SMX-resistant isolates positive for integrons, 44 had class 1 and 16 had class 2 integrons. It was found that the prevalence of sul genes (n = 202; p < 0.001) was higher compared with dfr genes (n = 80; p < 0.001), and 87.4% (n = 132; p < 0.001) of TMP-SMX-resistant isolates also were positive for β-lactamase production. This type of study is reported for the first time from HIV patients in India. Therefore, this study indicates that dissemination of TMP-SMX resistance genes and class 1 and class 2 integrons along with β-lactamase production among gram-negative bacteria in HIV patients will certainly make their treatment to bacterial infections more complicated in clinical settings.201727854149
2773190.9963Genotypic Characterization of Aminoglycoside Resistance Genes from Bacteria Isolates in Selected Municipal Drinking Water Distribution Sources in Southwestern Nigeria. BACKGROUND: Multi-drug Resistant (MDR) bacteria could lead to treatment failure of infectious diseases and could be transferred by non-potable water. Few studies have investigated occurrence of Antibiotic Resistance Genes (ARGs) among bacteria including Aminoglycoside Modifying Genes (AMGs) from Drinking Water Distribution Systems (DWDS) in Nigeria. Here, we aimed at characterization of AMGs from DWDS from selected states in southwestern Nigeria. METHODS: One hundred and eighty one (181) MDR bacteria that had been previously characterized using 16S rDNA and showed resistance to at least one aminoglycoside antibiotic were selected from treated and untreated six water distribution systems in southwestern Nigeria. MDR bacteria were PCR genotyped for three AMGs:aph (3″)(c), ant (3″)(b) and aph(6)-1d(d). RESULTS: Out of 181 MDR bacteria genotyped, 69(38.12%) tested positive for at least one of the genotyped AMGs. Highest (50, 27.62%) detected gene was ant (3″)(c) followed by aph (3″)(c)(33, 18.23%). Combination of aph(3″)(c) and ant (3″)(b) in a single bacteria was observed as the highest (14, 7.73%) among the detected gene combination. Alcaligenes sp showed the highest (10/20) occurrence of ant (3″)(b) while aph(3″)(c) was the highest detected among Proteus sp (11/22). Other bacteria that showed the presence of AMGs include: Acinetobacter, Aeromonas, Bordetella, Brevundimonas, Chromobacterium, Klebsiella, Leucobacter, Morganella, Pantoae, Proteus, Providencia, Psychrobacter and Serratia. CONCLUSIONS: High occurrence of ant (3″)(c) and aph (3″)(c) among these bacteria call for urgent attention among public health workers, because these genes can be easily disseminated to consumers of these water samples if present on mobile genetic elements like plasmids, integrons and transposons.201931447500