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Aims This research focused on assessing the prevalence of plasmid-mediated quinolone resistance (PMQR) determinants and antimicrobial susceptibility in Salmonella strains isolated from Thai canal water. Methods and results From 2016 to 2020, 333 water samples were collected from six canals across Bangkok, Thailand. Salmonella spp. was isolated, PMQR genes were detected through polymerase chain reactions, and the antimicrobial susceptibility was examined using the disk diffusion method. The results indicated a 92.2% prevalence of Salmonella spp. in canal water, being serogroups B and C the most frequently detected. Overall, 35.3% of isolates harbored PMQR genes, being qnrS the most prevalent gene (97.2%, n  = 137/141). Other PMQR genes, including qnrB, qnrD, oqxAB , and aac(6′)-Ib-cr , were detected. Notably, six isolates harbored multiple PMQR genes. Furthermore, 9.3% and 3.8% of the overall isolates were resistant to nalidixic acid (NAL) and ciprofloxacin (CIP), respectively. PMQR-positive isolates showed higher rates of non-susceptibility to both NAL (48.2%, n  = 68/141) and CIP (92.2%, n  = 130/141) compared to PMQR-negative isolates (NAL: 8.9%, n  = 23/258; CIP: 11.2%, n  = 30/258). Conclusions The high prevalence of Salmonella spp. significant PMQR-positive, and reduced susceptibility isolates in canal water is of public health concern in Bangkok. [ABSTRACT FROM AUTHOR]

Background: Bacterial resistance to commonly-used antibiotics has been on the increase especially in the clinical settings. This study focused on the detection of plasmid-mediated quinolone resistance (PMQR) determinants in ciprofloxacin-resistant bacteria recovered from Urinary Tract Infection (UTI) samples. Results: Already characterized isolates from urine samples of UTI-diagnosed in- and out- patients were obtained from the culture pool of the Department of Medical Microbiology and Parasitology, University College Hospital (UCH), Ibadan, Nigeria. A total of seventy-three ciprofloxacin-resistant isolates were used in this study. Of the 73 UTI isolates, 43 carried at least one of the four PMQR genes targeted and they belonged to eight bacterial genera namely: Escherichia (25), Klebsiella (10), Pseudomonas (2), Proteus (2) and one isolate each belonging to Enterobacter, Acinetobacter, Citrobacter and Salmonella genera. qnrA was detected in 10.9% (8/73) of the isolates while the occurrence of qnrB and qnrS was 32.9% (24/73) and 20.5% (15/73), respectively. The quinolone efflux pump (qepA) was detected in 9/73 (12.3%) of the isolates. Thirty of the isolates carried only one PMQR gene, while thirteen carried two PMQR genes. There was no carriage of more than two PMQR genes in the forty-three isolates from which PMQR genes were detected. Conclusion: This study reports the carriage of PMQR determinants by eight of the nine Gram-negative bacterial genera from urinary sources in patients attending the University College Hospital, Ibadan over the four-month period of study. This is quite worrisome as it suggests a high contribution of UTI cases to the burden of quinolone resistance. There is a need for more studies of this nature in other hospitals in Nigeria, to develop a database on the contribution of UTI cases to quinolone resistance. [ABSTRACT FROM AUTHOR]

Development of antibiotic resistance in bacteria has challenged significantly in both veterinary and human medicine. In this study, we analyzed the potential risk of pet turtles harboring tribe Proteeae as a source of quinolone-resistant determinants, including plasmid-mediated quinolone resistance (PMQR) genes and target gene alterations in the quinolone resistance-determining region (QRDR). Antimicrobial susceptibility of 54 Proteeae isolates against ciprofloxacin, ofloxacin, levofloxacin, and nalidixic acid was examined. The PMQR genes and QRDR alterations were identified using conventional PCR assays and sequencing. Four isolates were resistant to all quinolones tested in this study. Nine isolates showed resistance to nalidixic acid and showed either intermediate resistance or susceptibility to other tested quinolones. All isolates resistant to one or more tested quinolones harbored mutations in gyrB and some also had gyrA and parC mutations. Of 54, 12 Proteeae isolates displayed the novel E466D, N440T, Q411S, and F417L mutations in gyrB. Among the PMQR genes, 41 (76%) isolates harbored the qnrD gene with the highest prevalence, whereas aac(6′)Ib-cr, qnrS, qnrA, and qnrB genes were detected in 28 (52%), 9 (17.0%), 7 (13.0%), and 1 (1.9%) study isolates, respectively. The QRDR analysis of selected mutants revealed that increasing quinolone selective pressure led to a predominance of gyrA mutants. All results indicate that a healthy pet turtle can play as a potential reservoir for quinolone-resistant Proteeae, which it might cause public health risk on pet owners. [ABSTRACT FROM AUTHOR]

Abstract: The spread of antimicrobial resistance from human activity derived sources to natural habitats implicates wildlife as potential vectors of antimicrobial resistance transfer. Wild birds, including corvid species can disseminate mobile genetic resistance determinants through faeces. This study aimed to determine the occurrence of plasmid‐mediated quinolone resistance (PMQR) genes in Escherichia coli and Klebsiella spp. isolates obtained from winter roosting sites of American crows (Corvus brachyrhynchos) and common ravens (Corvus corax) in Canada. Faecal swabs were collected at five roosting sites across Canada. Selective media isolation and multiplex PCR screening was utilized to identify PMQR genes followed by gene sequencing, pulse‐field gel electrophoresis and multilocus sequence typing to characterize isolates. Despite the low prevalence of E. coli containing PMQR (1·3%, 6/449), qnrS1, qnrB19, qnrC, oqxAB and aac(6′)‐Ib‐cr genes were found in five sequence types (ST), including E. coli ST 131. Conversely, one isolate of Klebsiella pneumoniae contained the plasmid‐mediated resistance gene qnrB19. Five different K. pneumoniae STs were identified, including two novel types. The occurrence of PMQR genes and STs of public health significance in E. coli and Klebsiella pneumoniae recovered from corvids gives further evidence of the anthropogenic derived dissemination of antimicrobial resistance determinants at the human activity‐wildlife‐environment interface. Significance and Impact of the Study: This study examined large corvids as possible vector species for the dissemination of antimicrobial resistance in indicator and pathogenic bacteria as a means to assess the anthropogenic dissemination of plasmid‐mediated quinolone resistance (PMQR) genes. Although rare, PMQR genes were found among corvid populations across Canada. The clinically important Escherichia coli strain ST131 containing aac(6′)‐Ib‐cr gene along with a four‐class phenotypic antimicrobial resistance (AMR) pattern as well as one Klebsiella pneumoniae strain containing a qnrB19 gene were identified in one geographical location. Corvids are a viable vector for the circulation of PMQR genes and clinically important clones in wide‐ranging environments. [ABSTRACT FROM AUTHOR]

Antimicrobial usage in aquaculture selects for antimicrobial-resistant microorganisms in the marine environment. The relevance of this selection to terrestrial animal and human health is unclear. Quinolone-resistance genes qnrA, qnrB, and qnrS were chromosomally located in four randomly chosen quinolone-resistant marine bacteria isolated from an aquacultural area with heavy quinolone usage. In quinolone-resistant uropathogenic clinical isolates of Escherichia coli from a coastal area bordering the same aquacultural region, qnrA was chromosomally located in two E. coli isolates, while qnrB and qnrS were located in small molecular weight plasmids in two other E. coli isolates. Three quinolone-resistant marine bacteria and three quinolone-resistant E. coli contained class 1 integrons but without physical association with PMQR genes. In both marine bacteria and uropathogenic E. coli, class 1 integrons had similar co-linear structures, identical gene cassettes, and similarities in their flanking regions. In a Marinobacter sp. marine isolate and in one E. coli clinical isolate, sequences immediately upstream of the qnrS gene were homologous to comparable sequences of numerous plasmid-located qnrS genes while downstream sequences were different. The observed commonality of quinolone resistance genes and integrons suggests that aquacultural use of antimicrobials might facilitate horizontal gene transfer between bacteria in diverse ecological locations. [ABSTRACT FROM AUTHOR]

Background: Inappropriate use of antibiotics in swine feed could cause accelerated emergence of antibiotic resistance genes, and agricultural application of swine waste could spread antibiotic resistance genes to the surrounding environment. Objectives: We investigated the distribution of plasmid-mediated quinolone resistance (PMQR) genes from swine feedlots and their surrounding environment. Methods: We used a culture-independent method to identify PMQR genes and estimate their levels in wastewater from seven swine feedlot operations and corresponding wastewater-irrigated farm fields. Concentrations of (fluoro)quinolones in wastewater and soil samples were determined by ultra-performance liquid chromatography-electrospray tandem mass spectrometry. Results: The predominant PMQR genes in both the wastewater and soil samples were qnrD, qepA, and oqxB, whereas qnrS and oqxA were present only in wastewater samples. Absolute concentrations of all PMQR genes combined ranged from 1.66 × 107 to 4.06 × 108 copies/mL in wastewater and 4.06 × 106 to 9.52 × 107 copies/g in soil. Concentrations of (fluoro)quinolones ranged from 4.57 to 321 ng/mL in wastewater and below detection limit to 23.4 ng/g in soil. Significant correlations were found between the relative abundance of PMQR genes and (fluoro)quinolone concentrations (r = 0.71, p = 0.005) and the relative abundance of PMQR genes in paired wastewater and agricultural soil samples (r = 0.91, p = 0.005). Conclusions: Swine feedlot wastewater may be a source of PMQR genes that could facilitate the spread of antibiotic resistance. To our knowledge, this is the first study to examine the occurrence of PMQR genes in animal husbandry environments using a culture-independent method. [ABSTRACT FROM AUTHOR]

Abstract: Escherichia coli is a common uropathogen causing community-acquired urinary tract infections (UTIs). Out of 4735 E. coli community-acquired UTIs, 10.2% were extended spectrum β-lactamases (ESBL)-producing. The identified ESBL types were CTX-M-15 (96.4%), SHV-2a (3%), and TLA-1 (1%). Of the isolates, 94.6% tested positive for plasmid-mediated quinolone resistance (PMQR) genes (aac(6′)-lb-cr [92.1%] and qepA1 [7%] and for qnr-determinants [3.5%]). E. coli O25b-ST131 was identified in 25% of the isolates that harbor a non-conjugative 160-kb plasmid (IncFIA) containing the CTX-M-15, and all of these isolates were found to contain PMQR genes. This work can be useful in modeling the potential impact that may have on community-acquired UTIs in Mexico. [Copyright &y& Elsevier]

Salmonella 4,[5],12:i:- is a monophasic variant of Salmonella Typhimurium, which is responsible for global foodborne disease outbreaks. Here, 255 S. 4,[5],12:i:- strains isolated from humans (11.0%) or food-borne animals (89.0%) between 2010 and 2018 were examined. Tests of susceptibility to 19 antimicrobial agents using the broth micro dilution method showed that 99.2% (n = 253) of the isolates were resistant to at least one compound. Antibiotic susceptibility analysis demonstrated that 91.8% of the isolates were multidrug-resistant (MDR) strains with predominant resistance to tetracycline (90.6%), followed by resistance to ampicillin (86.3%), streptomycin (63.5%), chloramphenicol (62.7%), and trimethoprim-sulfamethoxazole (55.3%). The 5 major distinct patterns of multi-resistance were identified as R-type AST, R-type ACTSxt, R-type ACSTSxt, R-type ACGSTSxt and R-type ASTSxt. Among the PMQR genes examined in this study, oqxAB and aac (6')-Ib-cr were the most prevalent resistance genes in the multi-resistant isolates. Our findings highlight the prevalence of the resistance of S. 4,[5],12:i:- in some regions of China, and several common types of multidrug resistance phenotypes, to provide valuable information for epidemiological studies, risk management, and public health strategies. • Salmonella 4,[5],12:i:- was isolated from pigs, chickens, humans, geese and cats. • Multidrug resistance was detected in >91.8% of the S. 4,[5],12:i:- isolates. • The MDR patterns is comprehensive. • oqxAB and aac(6′)-Ib-cr were the common plasmid-mediated quinolone resistance genes. [ABSTRACT FROM AUTHOR]

Vibrio parahaemolyticus is the leading cause of foodborne bacterial poisoning in China. The aim of this research is to conduct a study on the prevalence, virulence, and antimicrobial resistance of V. parahaemolyticus from different types of food samples in 12 different cities of China. Since fluoroquinolones are the major choice of treatment for V. parahaemolyticus infections, the genetic basis for fluoroquinolone resistance in V. parahaemolyticus were also investigated. V. parahaemolyticus was detected in 163 of the 784 food samples collected from 12 different cities in China, resulting in a prevalence of 20.79%. The prevalence of V. parahaemolyticus in ready-to-eat (RTE) food (4.96%) was much lower than those of shrimp (32.62%) and fish (22.00%). Virulence gene screening showed that 44 (27.00%) V. parahaemolyticus strains carried at least one virulence gene. Four isolates from shrimp and three isolates from fish contained both the virulence genes tdh and trh. In addition, the trh was firstly detected in one isolate collected from RTE food. All isolates exhibited relatively high resistance rates to ampicillin (82.21%), gentamicin (19.63%), and tetracycline (14.11%), while <10% of strains were resistant to ciprofloxacin (4.91%), levofloxacin (4.91%), and tetracycline (4.29%). Eight fluoroquinolone-resistant V. parahaemolyticus were selected to determine the molecular basis for fluoroquinolone resistance. These eight isolates belonged to three different types according to enterobacterial repetitive intergenic consensus sequence PCR (ERIC-PCR). A Ser83Ile substitution in GyrA was deteted in seven fluoroquinolone-resistant strains, except V209 which harbored a Ser83Phe substitution in GyrA. Moreover, A Ser85Leu substitution in ParC was found in five isolates (V52, V53, V61, V163, and V209). Plasmid-mediated quinolone resistance (PMQR) genes were detected in all eight fluoroquinolone-resistant V. parahaemolyticus strains. This is the first report of Ser83Phe substitution in GyrA, qnrD and qnrS1 in V. parahaemolyticus. The information generated in this study will provide valuable information for risk assessment of V. parahaemolyticus infections and future control of antibiotic-resistant V. parahaemolyticus species in China. • The prevalence of V. parahaemolyticus in RTE foods was lower than those of seafoods. • 44 (27.00%) V. parahaemolyticus strains carried at least one virulence gene. • The virulence gene trh was firstly detected in one isolate collected from RTE foods. • Ser83Phe mutation in GyrA was identified in V. parahaemolyticus for the first time. • PMQR genes qnrD and qnrS1 were detected in V. parahaemolyticus for the first time. [ABSTRACT FROM AUTHOR]