# | Rank | Similarity | Title + Abs. | Year | PMID |
|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | 5 |
| 1233 | 0 | 0.9304 | Prevalence, Antibiogram, and Resistance Profile of Extended-Spectrum β-Lactamase-Producing Escherichia coli Isolates from Pig Farms in Luzon, Philippines. This cross-sectional study was conducted to determine the prevalence, antibiogram, and resistance profile of extended-spectrum β-lactamase-producing Escherichia coli (ESBL-EC) isolates from healthy pigs and pig farms in Luzon, Philippines. A total of 162 rectal samples from healthy finisher and breeder pigs and boot swab samples from pig houses were collected from 54 randomly selected pig farms. Bacteria were isolated and screened using MacConkey agar plate supplemented with 1 mg/L cefotaxime. Identification of bacteria and antimicrobial susceptibility test were carried out through Vitek(®) 2 and combined disk test. PCR amplifications were carried out in all isolates targeting bla(CTX-M) and its five major groupings, bla(TEM), and bla(SHV). The farm prevalence of ESBL-EC was 57.41% (95% confidence interval [CI] = 43.21-70.77). A total of 48 (29.63%) ESBL-EC isolates were isolated from samples that showed 14 different phenotypic multidrug resistance patterns. The prevalence of bla(CTX-M) gene was 91.67% (95% CI = 80.02-97.68). All major bla(CTX-M-groups) except bla(CTX-M-25group) were detected. The bla(CTX-M-1) was the most prevalent bla(CTX-M) gene, 75.0% (95% CI = 60.40-86.36). The prevalence of bla(TEM) and bla(SHV) genes was 91.67% (95% CI = 80.02-97.68) and 60.42% (95% CI = 45.27-74.23), respectively. Coexistence of different bla(CTX-M), bla(TEM), and bla(SHV) genes was observed in 44 isolates with 20 different genotypic patterns. High prevalence, diverse antibiogram profile, and genotypic resistance pattern of ESBL-EC isolates from healthy pigs and pig farms were observed in this study that could result in possible transmission to farm workers, susceptible bacteria, and the environment. | 2020 | 31532307 |
| 1232 | 1 | 0.9298 | Monitoring of Non-β-Lactam Antibiotic Resistance-Associated Genes in ESBL Producing Enterobacterales Isolates. Genetic context of extended spectrum β-Lactamase (ESBL) producing Enterobacterales and its association with plasmid mediated quinolone resistance (PMQR), aminoglycoside modifying enzymes (AME) and Trimethoprim/Sulfamethoxazole (TMP-SMX) resistance is little known from North India. Therefore, the current study was aimed to investigate the frequency of Non-β-Lactam antibiotic resistance associated genes in extended spectrum β-Lactamase producing Enterobacterales. For this study, Non-Duplicate phenotypically confirmed ESBL producing Enterobacterales isolates (N = 186) were analyzed for ESBLs, PMQRs, AMEs and TMP-SMX resistance genes using polymerase chain reaction (PCR). PCR detected presence of PMQR genes in 81.29% (N = 139) of ESBL isolates (N = 171), AME genes in 60.82% and TMP-SMX resistance genes in 63.74% of the isolates. Molecular characterization of ESBL producing Enterobacterales showed 84.79% bla(TEM) followed by 73.68% bla(CTX-M), 43.86% bla(SHV), 19.88% bla(PER) and 9.94% bla(VEB), respectively. Analysis of PMQR genes revealed 77.7% aac(6')-lb-cr the most commonly detected gene followed by 67.63% oqxB, 62.59% oqxA, 43.17% qnrB, 19.42% qnrD, 18.7% qnrS, 9.35% qnrA, 3.6% qepA and 2.88% qnrC, respectively. Analysis of AMEs gene profile demonstrated 81.73% aac(6')-Ib, the most frequently encountered gene followed by 46.15% aph(3')-Ia, 44.23% ant(3")-Ia, respectively. A 100% prevalence of sul1, followed by dfrA (54.63%) and sul2 (15.74%) was observed. In summary, prevalence of ESBL-Producing genes (particularly bla(TEM) and bla(CTX-M)) along with PMQR, AMEs, and TMP-SMX resistant genes may potentially aid in the transfer of antimicrobial resistance among these strains. | 2020 | 33317078 |
| 1235 | 2 | 0.9290 | Characterization of integrons and antimicrobial resistance genes in clinical isolates of Gram-negative bacteria from Palestinian hospitals. Sixty Gram-negative bacterial isolates were collected from Palestinian hospitals in 2006. Thirty-two (53.3%) isolates showed multidrug resistance phenotypes. PCR and DNA sequencing were used to characterize integrons and antimicrobial resistance genes. PCR screening showed that 19 (31.7%) and five (8.3%) isolates were positive for class 1 and class 2 integrons, respectively. DNA-sequencing results for the captured antimicrobial resistance gene cassettes within class 1 integrons identified the following genes: dihydrofolate reductases, dfrA1, dfrA5, dfrA7, dfrA12, dfrA17 and dfrA25; aminoglycoside adenyltransferases, aadA1, aadA2, aadA5, aadA12 and aadB; aminoglycoside acetyltransferase, aac(6')-Ib; and chloramphenicol resistance gene, cmlA1. ESBL were identified in 25 (41.7%) isolates. The identified ESBL were bla(CTX-M-15), bla(CTX-M-56), bla(OXA-1), bla(SHV-1), bla(SHV-12), bla(SHV-32) and bla(TEM-1) genes. Moreover, we characterized the plasmid-mediated quinolone resistance genes, aac(6')-Ib-cr and qnrB2, which were detected in seven (11.7%) and two (3.3%) isolates, respectively. In this study various types of antibiotic resistance genes have been identified in Gram-negative bacteria from Palestinian hospitals, many of which are reported in the Middle East area for the first time. | 2009 | 19903259 |
| 1236 | 3 | 0.9289 | Molecular characterization of antimicrobial resistance in Gram-negative bacteria isolated from bovine mastitis in Egypt. The aim of this study was to characterize the genetic basis of multidrug resistance in Gram-negative bacteria isolated from bovine mastitis cases in Egypt. Multidrug resistance phenotypes were found in 34 of 112 (30.4%) Gram-negative bacterial isolates, which harbored at least one antimicrobial resistance gene. The most prevalent multidrug-resistant (MDR) species were Enterobacter cloacae (8 isolates, 7.1%), Klebsiella pneumoniae (7 isolates, 6.3%), Klebsiella oxytoca (7 isolates, 6.3%), Escherichia coli (5 isolates, 4.5%), and Citrobacter freundii (3 isolates, 2.7%). The most commonly observed resistance phenotypes were against ampicillin (97.0%), streptomycin (94.1%), tetracycline (91.2%), trimethoprim-sulfamethoxazole (88.2%), nalidixic acid (85.3%), and chloramphenicol (76.5%). Class 1 integrons were detected in 28 (25.0%) isolates. The gene cassettes within class 1 integrons included those encoding resistance to trimethoprim (dfrA1, dfrA5, dfrA7, dfrA12, dfrA15, dfrA17, and dfrA25), aminoglycosides (aadA1, aadA2, aadA5, aadA7, aadA12, aadA22, and aac(3)-Id), chloramphenicol (cmlA), erythromycin (ereA2), and rifampicin (arr-3). Class 2 integrons were identified in 6 isolates (5.4%) with three different profiles. Furthermore, the β-lactamase encoding genes, bla(TEM), bla(SHV), bla(CTX-M), and bla(OXA), the plasmid-mediated quinolone resistance genes, qnr and aac(6)-Ib-cr, and the florfenicol resistance gene, floR, were also identified. To the best of our knowledge, the results identified class 2 integrons, qnr and aac(6)-Ib-cr from cases of mastitis for the first time. This is the first report of molecular characterization for antimicrobial resistance in Gram-negative bacteria isolated from bovine mastitis in Africa. | 2011 | 21338385 |
| 1226 | 4 | 0.9289 | Multi-drug resistant gram-negative enteric bacteria isolated from flies at Chengdu Airport, China. We collected flies from Chengdu Shuangliu International Airport to examine for the presence of bacteria and to determine the sensitivity patterns of those bacteria. A total of 1,228 flies were collected from 6 sites around Chengdu Shuangliu International Airport from April to September 2011. The predominant species was Chrysomya megacephala (n=276, 22.5%). Antimicrobial-resistant gram-negative enteric bacteria (n=48) were isolated from flies using MacConkey agar supplemented with cephalothin (20 microg/ml). These were identified as Escherichia coli (n=37), Klebsiella pneumoniae (n=6), Pseudomonas aeruginosa (n=3) and Aeromonas hydrophila (n=2). All isolated bacteria were tested for resistance to 21 commonly used antimicrobials: amoxicillin (100%), ticarcillin (100%), cephalothin (100%), cefuroxime (100%), ceftazidime 1 (93.8%), piperacillin (93.8%), cefotaxime (89.6%), ticarcillin-clavulanate (81.3%), trimethoprim-sulfamethoxazole (62.5%), ciprofloxacin (54.2%), gentamicin (45.8%), cefepime (39.6%), tobramycin (39.6%), ceftazidime (22.9%), cefoxitin (16.7%), amikacin (16.7%), netilmicin (14.6%), amoxicillin-clavulanate (6.3%) and piperacillin-tazobactam (2.1%). No resistance to meropenem or imipenem was observed. Antibiotic resistance genes among the isolated bacteria were analyzed for by polymerase chain reaction. Thirty of the 48 bacteria with resistance (62.5%) possessed the blaTEM gene. | 2013 | 24450236 |
| 1413 | 5 | 0.9287 | Occurrence of Carbapenemases, Extended-Spectrum Beta-Lactamases and AmpCs among Beta-Lactamase-Producing Gram-Negative Bacteria from Clinical Sources in Accra, Ghana. Beta-lactamase (β-lactamase)-producing Gram-negative bacteria (GNB) are of public health concern due to their resistance to routine antimicrobials. We investigated the antimicrobial resistance and occurrence of carbapenemases, extended-spectrum β-lactamases (ESBLs) and AmpCs among GNB from clinical sources. GNB were identified using matrix-assisted laser desorption/ionization time of flight-mass spectrometry (MALDITOF-MS). Antimicrobial susceptibility testing was performed via Kirby-Bauer disk diffusion and a microscan autoSCAN system. β-lactamase genes were determined via multiplex polymerase chain reactions. Of the 181 archived GNB analyzed, Escherichia coli and Klebsiella pneumoniae constituted 46% (n = 83) and 17% (n = 30), respectively. Resistance to ampicillin (51%), third-generation cephalosporins (21%), and ertapenem (21%) was observed among the isolates, with 44% being multi-drug resistant (MDR). β-lactamase genes such as AmpCs ((bla(FOX-M) (64%) and bla(DHA-M) and bla(EDC-M) (27%)), ESBLs ((bla(CTX-M) (81%), other β-lactamase genes bla(TEM) (73%) and bla(SHV) (27%)) and carbapenemase ((bla(OXA-)(48) (60%) and bla(NDM) and bla(KPC) (40%)) were also detected. One K. pneumoniae co-harbored AmpC (bla(FOX-M) and bla(EBC-M)) and carbapenemase (bla(KPC) and bla(OXA-)(48)) genes. bla(OXA-)(48) gene was detected in one carbapenem-resistant Acinetobacter baumannii. Overall, isolates were resistant to a wide range of antimicrobials including last-line treatment options. This underpins the need for continuous surveillance for effective management of infections caused by these pathogens in our settings. | 2023 | 37370334 |
| 1411 | 6 | 0.9285 | Detection and characterization of carbapenem resistant Gram-negative bacilli isolates recovered from hospitalized patients at Soba University Hospital, Sudan. BACKGROUND: Antimicrobial resistance (AMR) poses a complex threat to global health security and universal health coverage. Recently, nosocomial infections with carbapenemase-producing Gram-negative bacilli (GNB) is increasing worldwide. We report the molecular characterization and detection of genes associated with carbapenemase producing Gram negative bacteria isolated from hospitalized patients at Soba University Hospital (SUH) in Khartoum State, Sudan. RESULTS: Between October 2016 and February 2017, a total of 206 GNB clinical specimens were collected from hospitalized patients in SUH. Of 206 carbapenem resistance isolates, 171 (83 %) were confirmed as phenotypically resistant and 121 (58.7 %) isolates harboured one or more carbapenemase genes. New Delhi metallo-β-lactamase (NDM) types were the most predominant genes, blaNDM 107(52 %), followed by blaIMP 7 (3.4 %), blaOXA-48 5(2.4 %) and blaVIM 2 (0.9 %). Co-resistance genes with NDM producing GNB were detected in 87 (81.3 %) of all blaNDM producing isolates. NDM-1 was the most frequent subtype observed in 75 (70 %) blaNDM producing isolates. The highest percentage of resistance was recorded in ampicillin (98 %), cephalexin (93.5 %) amoxicillin clavulanic acid (90 %), cefotaxime (89.7 %), ceftriaxone (88.4 %), ceftazidime (84.2 %), sulfamethoxazole-trimethoprim (78.4 %) and nitrofurantoin (75.2 %), aztreonam (66 %) and temocillin (64 %). A close correlation between phenotypic and carbapenemase genes detection in all GNB was observed. CONCLUSIONS: The frequency of carbapenemase producing bacilli was found to be high in SUH. NDM was found to be the most prevalent carbapenemase gene among clinical isolates. Close surveillance across all hospitals in Sudan is required. The relative distribution of carbapenemase genes among GNB in nosocomial infections in Africa needs to be defined. | 2021 | 33947325 |
| 1451 | 7 | 0.9278 | Molecular Epidemiology of Extensively Drug-Resistant mcr Encoded Colistin-Resistant Bacterial Strains Co-Expressing Multifarious β-Lactamases. Plasmid-mediated colistin resistance (Col-R) conferred by mcr genes endangers the last therapeutic option for multifarious β-lactamase-producing bacteria. The current study aimed to explore the mcr gene molecular epidemiology in extensively drug-resistant (XDR) bacteria. Col-R gram-negative bacterial strains were screened using a minimum inhibitory concentration (MIC) breakpoint ≥4 µg/mL. Resistant isolates were examined for mcr variants, extended-spectrum β-lactamase, AmpC, and carbapenemase genes using polymerase chain reaction (PCR). The MIC breakpoints for mcr-positive strains were determined using broth microdilution and E-test strips. Overall, 19/718 (2.6%) gram-negative rods (GNRs) harboring mcr were identified, particularly in pus (p = 0.01) and tracheal secretions (p = 0.03). Molecular epidemiology data confirmed 18/19 (95%) mcr-1 and 1/19 (5%) mcr-2 genes. Integron detection revealed 15/17 (88%) Int-1 and 2/17 (12%) Int-2. Common co-expressing drug-resistant β-lactamase genes included 8/16 (50%) bla(CTM-1), 3/16 (19%) bla(CTM-15), 3/3 (100%) bla(CMY-2), 2/8 (25%) bla(NDM-1), and 2/8 (25%) bla(NDM-5). The MIC(50) and MIC(90) values (µg/mL) were as follows: Escherichia coli, 12 and 24; Klebsiella pneumoniae, 12 and 32; Acinetobacter baumannii, 8 and 12; and Pseudomonas aeruginosa, 32 and 64, respectively. Treatment of XDR strains has become challenging owing to the co-expression of mcr-1, mcr-2, multifarious β-lactamase genes, and integrons. | 2021 | 33923991 |
| 1421 | 8 | 0.9278 | Predominance of Acinetobacter spp., Harboring the bla(IMP) Gene, Contaminating the Hospital Environment in a Tertiary Hospital in Mwanza, Tanzania: A Cross-Sectional Laboratory-Based Study. Data on colonization and hospital contamination of carbapenem-resistant Gram-negative bacteria (CR-GNB) are limited in low- and middle-income countries. We designed this study to determine the prevalence and co-existence of carbapenemase genes among CR-GNB isolated from clinical, colonization, and hospital environmental samples at a tertiary hospital in Mwanza, Tanzania. The modified Hodge test (MHT), the combined disk test (CDT), and the double-disk synergy test (DDST) were used for the phenotypic detection of carbapenemases. A multiplex PCR assay was used to detect bla(IMP) and bla(KPC), and a singleplex PCR assay was used to detect bla(OXA-48). Data were analyzed by STATA version 13.0. Overall, 68.8% (44/64) of the CR-GNB had at least one phenotype by phenotypic methods, whereby 60.9% (39/64) were both CDT and DDST positive and 31.3% (20/64) were MHT positive. A total of 23/64 (35.9%) had at least one of the genes tested with the predominance of bla(IMP) (91.3%; 21/23). In addition, 47.7% (21/44) of the CR-GNB phenotypes had at least one gene. Around 47.8% (11/23) of the CR-GNB carried multiple genes encoding for carbapenem resistance, with the maximum co-existence of bla(IMP)/bla(KPC)/bla(OXA-48) (45.5%; 5/11). The majority of carbapenem-resistant genes were detected in Acinetobacter spp. (82.6%; 19/23) and isolated from bed swabs (69.6%; 16/23). Acinetobacter spp. carrying the bla(IMP) gene predominantly contaminated the hospital environment. Therefore, we recommend routine decontamination of inanimate hospital surfaces, including patient beds. | 2022 | 35056011 |
| 1240 | 9 | 0.9277 | Prevalence and characterization of quinolone resistance and integrons in clinical Gram-negative isolates from Gaza strip, Palestine. BACKGROUND: Gram-negative bacteria with quinolone resistance and extended-spectrum beta-lactamases (ESBLs) present significant treatment challenges. This study evaluated the prevalence and characteristics of quinolone resistance in Gram-negative strains, investigating the relationship between plasmid-mediated quinolone resistance (PMQR), ESBLs, and integrons. METHODS AND RESULTS: We collected 146 Gram-negative isolates from patients in three Palestinian hospitals. For quinolone resistance isolates, the presence and characterization of PMQR, β-lactamase genes and integrons were studied by PCR and sequencing. Out of 146 clinical isolates, 64 (43.8%) were resistant to quinolones, with 62 (97%) being multidrug-resistant (MDR) and 33 (51.5%) ESBL-producers. PMQR-encoding genes were present in 45 (70.3%) isolates, including aac(6')-Ib-cr (26.6%), qnrA (18.8%), qnrS1 (20.8%), and qnrB (6.4%). Bla(CTX-M) genes were detected in 50% (32/64) of isolates, with bla(CTX-M-15) being the most common. Bla(TEM-1), bla(SHV-1) and bla(VIM) genes were found in 13, 6, and 4 isolates, respectively. Class I integrons were found in 31/64 (48%) of isolates, with 14 containing gene cassettes conferring resistance to trimethoprim (dhfr17, dfrA12, dfrA1) and aminoglycosides resistance genes (aadA1, aadA2, aadA5, and aadA6). CONCLUSIONS: This study found a high rate of quinolone resistance, ESBL and integrons in clinical Gram-negative isolates from our hospitals. Urgent measures are crucial, including implementing an antimicrobial resistance surveillance system, to control and continuously monitor the development of antimicrobial resistance. | 2024 | 39066817 |
| 1409 | 10 | 0.9277 | Detection of diverse carbapenem and multidrug resistance genes and high-risk strain types among carbapenem non-susceptible clinical isolates of target gram-negative bacteria in Kenya. Carbapenem-resistant gram-negative bacteria are an increasingly significant clinical threat globally. This risk may be underestimated in Kenya as only four carbapenemase genes in three bacterial species have been described. The study aimed to understand the antibiotic resistance profiles, genes, sequence types, and distribution of carbapenem-resistant gram-negative bacteria from patients in six hospitals across five Kenyan counties by bacterial culture, antibiotic susceptibility testing, and whole-genome sequence analysis. Forty-eight, non-duplicate, carbapenem non-susceptible, clinical isolates were identified across the five counties (predominantly in Nairobi and Kisii): twenty-seven Acinetobacter baumannii, fourteen Pseudomonas aeruginosa, three Escherichia coli, two Enterobacter cloacae, and two Klebsiella pneumoniae. All isolates were non-susceptible to β-lactam drugs with variable susceptibility to tigecycline (66%), minocycline (52.9%), tetracycline (29.4%), and levofloxacin (22.9%). Thirteen P. aeruginosa isolates were resistant to all antibiotics tested. Eleven carbapenemase genes were identified: blaNDM-1, blaOXA-23, -58, -66, -69, and -91 in A. baumannii (STs 1, 2, 164 and a novel ST1475), blaNDM-1 in E. cloacae (STs 25,182), blaNDM-1, blaVIM-1and -6, blaOXA-50 in P. aeruginosa (STs 316, 357, 654, and1203), blaOXA-181, blaNDM-1 in K. pneumoniae (STs 147 and 219), and blaNDM-5 in E. coli (ST164). Five A. baumannii isolates had two carbapenemases, blaNDM-1, and either blaOXA-23 (4) or blaOXA-58 (1). AmpC genes were detected in A. baumannii (blaADC-25), E. cloacae (blaDHA-1 and blaACT-6, 16), and K. pneumoniae (blaCMY). Significant multiple-drug resistant genes were the pan-aminoglycoside resistance16srRNA methyltransferase armA, rmtB, rmtC, and rmtF genes. This study is the first to report blaOXA-420, -58, -181, VIM-6, and blaNDM-5 in Kenyan isolates. High-risk STs of A. baumannii (ST1475, ST2), E. cloacae ST182, K. pneumoniae ST147, P. aeruginosa (ST357, 654), and E. coli ST167, ST648 were identified which present considerable therapeutic danger. The study recommends urgent carbapenem use regulation and containment of high-risk carbapenem-resistant bacteria. | 2021 | 33617559 |
| 1412 | 11 | 0.9275 | A highly multiplexed melt-curve assay for detecting the most prevalent carbapenemase, ESBL, and AmpC genes. Resistance to third-generation cephalosporins and carbapenems in Gram-negative bacteria is chiefly mediated by beta-lactamases including extended-spectrum beta-lactamase (ESBL), AmpC, and carbapenemase enzymes. Routine phenotypic detection methods do not provide timely results, and there is a lack of comprehensive molecular panels covering all important markers. An ESBL/carbapenemase high-resolution melt analysis (HRM) assay (SHV, TEM, CTX-M ESBL families, and NDM, IMP, KPC, VIM and OXA-48-like carbapenemases) and an AmpC HRM assay (16S rDNA control, FOX, MOX, ACC, EBC, CIT, and DHA) were designed and evaluated on 111 Gram-negative isolates with mixed resistance patterns. The sensitivity for carbapenemase, ESBL, and AmpC genes was 96.7% (95% confidence interval [CI]: 82.8-99.9%), 93.6% (95% CI: 85.7-97.9%), and 93.8% (95% CI: 82.8-98.7%), respectively, with a specificity of 100% (95% CI: 95.6-100%), 93.9% (95% CI: 79.8-99.3%), and 93.7% (95% CI: 84.5-98.2%). The HRM assays enable the simultaneous detection of the 14 most important ESBL, carbapenemase, and AmpC genes and could be used as a molecular surveillance tool or to hasten detection of antimicrobial resistance for treatment management. | 2020 | 32521424 |
| 1417 | 12 | 0.9275 | Prevalence and Phenotypic and Molecular Characterization of Carbapenemase-Producing Gram-Negative Bacteria in Gabon. Data collection and monitoring of carbapenemase-producing (CP) Gram-negative bacteria (GNB) are often limited. This study determined CP-GNB prevalence in Gabon and the genetic origins of the resistance genes. From January 2016 to March 2018, 869 clinically significant GNB isolates from inpatients and outpatients, and 19 fecal samples (inpatients) were analyzed in the main hospitals of Gabon. Fecal samples were screened using ChromID® CARBA SMART selective chromogenic medium biplates. Species were identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry. Antibiotic susceptibility was tested using the disk diffusion method on Müller-Hinton agar, and resistance genes were assessed by multiplex polymerase chain reaction and sequencing. Overall, 1.61% of clinical isolates (14 of 869) and 5.26% of fecal samples (1 of 19) were CP-GNB. The CP-GNB rate was higher among inpatients (2.98%) than outpatients (0.33%), in intensive care units (28.57%, 4 of 14), and in urine samples (35.71%, 5 of 14). The most common CP-GNB were Klebsiella pneumoniae (53.33%) and Acinetobacter baumannii (26.67%). blaOXA-48 was the predominant carbapenemase-encoding gene (40%), followed by blaNDM-5 (33.33%). The A. baumannii multilocus sequence types ST2 and ST78, Enterobacter cloacae ST78, Escherichia coli ST2, and K. pneumonia ST48 and ST147 were found. These data indicate that CP bacteria are present in clinical and carriage samples. Preventive measures are needed to avoid the spread of resistance genes. | 2023 | 36535247 |
| 1229 | 13 | 0.9275 | Detection of multi-drug resistance and AmpC β-lactamase/extended-spectrum β-lactamase genes in bacterial isolates of loggerhead sea turtles (Caretta caretta) from the Mediterranean Sea. Sea turtles are useful sentinels to monitor the dissemination of antimicrobial resistance (AMR) in the marine coastal ecosystems. Forty Gram negative bacteria were isolated from wounds of 52 injured Caretta caretta, living in the Mediterranean Sea. Bacteria were identified using 16S rRNA gene sequencing and tested for susceptibility to 15 antibiotics. In addition, NGS amplicon sequencing was performed to detect the presence of AmpC β-lactamase genes (bla(AmpC)) and extended-spectrum β-lactamase (ESBL) genes (bla(CTX-M,)bla(SHV,)bla(TEM)). Seventy-five percent of the isolates (30/40 isolates) exhibited multidrug resistance (MDR) phenotypes and 32.5% (13/40 isolates) were confirmed to be positive for at least one gene. The variants of ESBLs genes were bla(CTX-M-3,)bla(TEM-236) and bla(SHV-12). Variants of the bla(AmpC)β-lactamase gene i.e., bla(ACT-24), bla(ACT-2), bla(ACT-17), bla(DHA-4) and bla(CMY-37), were also detected. In addition, 4 isolates were found simultaneously harboring CTX and AmpC genes while 2 strains harbored 3 genes (bla(ACT-2+TEM-236+SHV-12), and bla(CTX-M-3+ACT-24+TEM-236)). | 2021 | 33513540 |
| 1455 | 14 | 0.9274 | Resistance to bacterial infection, complication occurring after cardiac surgery. To analyze the occurrence of resistant bacterial infection in patients undergoing cardiac surgery hospitalized in the surgical specialty hospital, in Erbil city, Iraq. A prospective study was done on a total of 138 patients operated and hospitalized in an intensive care unit and surgical wards. Bacterial isolates identification was done according to cultural characteristics, microscopic examination, some biochemical tests, analytic Profile Index 20E& API Staph, confirmed with VITEK® 2 compact system (BioMérieux). Antimicrobial susceptibility for disc diffusion tested to 17 antimicrobial agents. Resistance isolates were confirmed phenotypically for carbapenemase by Rapidec Carba NP Test (bioMe´rieux SA, Marcy-l'E´toile, France) for ESBLs producers by ESBL screening test VITEK 2 system. Molecularly blaIMP blaTEM, blaKPC, AmpC and blaCTX-M were detected by PCR. In 134 patients, 28.3% of patients got infected post-operatively. The most frequent source of isolation was from ICU patients (75%). Isolated bacteria included gram-positive 29 (54.7%) and gram-negative bacteria 24 (45.3%). Most frequently: Staphylococcus aureus (24.4%), each of pseudomonas aeroginosa, Klebsiella pneumonia (15.1%), Streptococcus spp. (11.3%), Escherichia coli (9.4%). Whereas included Coagulase Negative Staphylococci species (CoNS) (13.2%) and Enterococci species (5.7) Statistical analysis showed significantly higher sensitive isolates as compared with resistance isolates. Resistance to Carbapenems calss was 18.9% and Cephalosporins class 41.5% of isolates. The antimicrobial resistance pattern indicated that MDR bacterial isolates (81.1%) were widespread. Of the 34 phenotypically ESBL positive isolates, the ESBL genes (AmpC, blaCTX-M, and blaTEM) were amplified in 7(20.6), 6(17.6) and 6(17.6) isolates respectively. Out of 8 K. pneumonia (37.5%) harboring both blaAmpC and bla-CTX-M genes, while 6(75%) carries blaTEM. The blaCTX-M gene was found in only 1 (12.5%) out of 8 isolates of P. aeruginosa. While blaAmpC genotyping revealed that 1(7.7%) out of 13 Staph. aureus isolates were harboring it. Finally, 3(60%) out of 5 E. coli isolates harboring both AmpC and bla-CTX-M genes. Cardiac surgery patients wound show increasingly emerging strains of ESBL-producing gram-negative bacteria K. pneumonia, P. aeruginosa and E. coli especially patients prolonged in the intensive care unit. | 2020 | 34174972 |
| 1410 | 15 | 0.9272 | A high prevalence of multi-drug resistant Gram-negative bacilli in a Nepali tertiary care hospital and associated widespread distribution of Extended-Spectrum Beta-Lactamase (ESBL) and carbapenemase-encoding genes. BACKGROUND: Multi-drug resistance (MDR) and extensive-drug resistance (XDR) associated with extended-spectrum beta-lactamases (ESBLs) and carbapenemases in Gram-negative bacteria are global public health concerns. Data on circulating antimicrobial resistance (AMR) genes in Gram-negative bacteria and their correlation with MDR and ESBL phenotypes from Nepal is scarce. METHODS: A retrospective study was performed investigating the distribution of ESBL and carbapenemase genes and their potential association with ESBL and MDR phenotypes in E. coli, Klebsiella spp., Enterobacter spp. and Acinetobacter spp. isolated in a major tertiary hospital in Kathmandu, Nepal, between 2012 and 2018. RESULTS: During this period, the hospital isolated 719 E. coli, 532 Klebsiella spp., 520 Enterobacter spp. and 382 Acinetobacter spp.; 1955/2153 (90.1%) of isolates were MDR and half (1080/2153) were ESBL producers. Upon PCR amplification, bla(TEM) (1281/1771; 72%), bla(CTXM-1) (930/1771; 53%) and bla(CTXM-8) (419/1771; 24%) were the most prevalent ESBL genes in the enteric bacilli. Bla(OXA) and bla(OXA-51) were the most common bla(OXA) family genes in the enteric bacilli (918/1771; 25%) and Acinetobacter spp. (218/382; 57%) respectively. Sixteen percent (342/2153) of all isolates and 20% (357/1771) of enteric bacilli harboured bla(NDM-1) and bla(KPC) carbapenemase genes respectively. Of enteric bacilli, Enterobacter spp. was the most frequently positive for bla(KPC) gene (201/337; 60%). The presence of each bla(CTX-M) and bla(OXA) were significantly associated with non-susceptibility to third generation cephalosporins (OR 14.7, p < 0.001 and OR 2.3, p < 0.05, respectively).The presence of each bla(TEM), bla(CTXM) and bla(OXA) family genes were significantly associated with ESBL positivity (OR 2.96, p < 0.001; OR 14.2, p < 0.001 and OR 1.3, p < 0.05 respectively) and being MDR (OR 1.96, p < 0.001; OR 5.9, p < 0.001 and OR 2.3, p < 0.001 respectively). CONCLUSIONS: This study documents an alarming level of AMR with high prevalence of MDR ESBL- and carbapenemase-positive ESKAPE microorganisms in our clinical setting. These data suggest a scenario where the clinical management of infected patients is increasingly difficult and requires the use of last-resort antimicrobials, which in turn is likely to intensify the magnitude of global AMR crisis. | 2020 | 33087115 |
| 1239 | 16 | 0.9272 | Fluoroquinolone resistance among fecal extended spectrum βeta lactamases positive Enterobacterales isolates from children in Dar es Salaam, Tanzania. BACKGROUND: Fluoroquinolones have been, and continue to be, routinely used for treatment of many bacterial infections. In recent years, most parts of the world have reported an increasing trend of fluoroquinolone resistant (FQR) Gram-negative bacteria. METHODS: A cross-sectional study was conducted between March 2017 and July 2018 among children admitted due to fever to referral hospitals in Dar es Salaam, Tanzania. Rectal swabs were used to screen for carriage of extended-spectrum β-lactamase-producing Enterobacterales (ESBL-PE). ESBL-PE isolates were tested for quinolone resistance by disk diffusion method. Randomly selected fluroquinolone resistant isolates were characterized by using whole genome sequencing. RESULTS: A total of 142 ESBL-PE archived isolates were tested for fluoroquinolone resistance. Overall phenotypic resistance to ciprofloxacin, levofloxacin and moxifloxacin was found in 68% (97/142). The highest resistance rate was seen among Citrobacter spp. (100%, 5/5), followed by Klebsiella. pneumoniae (76.1%; 35/46), Escherichia coli (65.6%; 42/64) and Enterobacter spp. (31.9%; 15/47). Whole genome sequencing (WGS) was performed on 42 fluoroquinolone resistant-ESBL producing isolates and revealed that 38/42; or 90.5%, of the isolates carried one or more plasmid mediated quinolone resistance (PMQR) genes. The most frequent PMQR genes were aac(6')-lb-cr (74%; 31/42), followed by qnrB1 (40%; 17/42), oqx, qnrB6 and qnS1. Chromosomal mutations in gyrA, parC and parE were detected among 19/42 isolates, and all were in E. coli. Most of the E. coli isolates (17/20) had high MIC values of > 32 µg/ml for fluoroquinolones. In these strains, multiple chromosomal mutations were detected, and all except three strains had additional PMQR genes. Sequence types, ST131 and ST617 predominated among E. coli isolates, while ST607 was more common out of 12 sequence types detected among the K. pneumoniae. Fluoroquinolone resistance genes were mostly associated with the IncF plasmids. CONCLUSION: The ESBL-PE isolates showed high rates of phenotypic resistance towards fluoroquinolones likely mediated by both chromosomal mutations and PMQR genes. Chromosomal mutations with or without the presence of PMQR were associated with high MIC values in these bacteria strains. We also found a diversity of PMQR genes, sequence types, virulence genes, and plasmid located antimicrobial resistance (AMR) genes towards other antimicrobial agents. | 2023 | 36882712 |
| 1231 | 17 | 0.9271 | Prevalence and Molecular Characterization of Plasmid-mediated Extended-Spectrum β-Lactamase Genes (balaTEM, blaCTX and blASHV) Among Urinary Escherichia coli Clinical Isolates in Mashhad, Iran. OBJECTIVES: Extended-spectrum beta-lactamase (ESBL) producing bacteria have an important role in nosocomial infections. Due to the limited availability of information about the molecular epidemiology of ESBL producing bacteria in Mashhad, we decided to investigate about TEM, CTX and SHV ESBLs among urinary Escherichia coli isolates in Mashhad, a city in northeast Iran. MATERIALS AND METHODS: One hundred and eleven clinical isolates of E. coli were diagnosed from hospitalized patients in 2009. After performing antibiogram and phenotypic confirmation test, polymerase chain reaction (PCR) was performed by blaTEM, blaSHV and blaCTX primers and restriction digestion was carried out using PstI and TaqI (Fermentas-Lithuania) for confirmation. RESULTS: ESBL producers of E. coli isolates were 33.3%. Among 37 ESBL-producing isolates, 35 (94.6%), 21 (56.8%) and 5 (13.5%) were shown to have blaCTX, blaTEM and blaSHV, genes respectively. Co-resistance to non-beta lactam antibiotics was observed more with ESBL producers (P < 0.05). CONCLUSION: The results showed that the studied ESBL genes are found with high prevalence and among them blaCTX is more widespread in urine E. coli isolates in Mashhad. | 2012 | 23493415 |
| 1237 | 18 | 0.9268 | Characterization of Gene Families Encoding Beta-Lactamases of Gram-Negative Rods Isolated from Ready-to-Eat Vegetables in Mexico City. Beta-lactam resistant bacteria, which are commonly resident in tertiary hospitals, have emerged as a worldwide health problem because of ready-to-eat vegetable intake. We aimed to characterize the genes that provide resistance to beta-lactam antibiotics in Enterobacteriaceae, isolated from five commercial salad brands for human consumption in Mexico City. In total, twenty-five samples were collected, grown in blood agar plates, and the bacteria were biochemistry identified and antimicrobial susceptibility testing was done. The carried family genes were identified by endpoint PCR and the specific genes were confirmed with whole genome sequencing (WGS) by Next Generation Sequencing (NGS). Twelve positive cultures were identified and their microbiological distribution was as follows: 8.3% for Enterobacter aerogene (n = 1), 8.3% for Serratia fonticola (n = 1), 16.7% for Serratia marcesens (n = 2), 16.7% for Klebsiella pneumoniae (n = 2), and 50% (n = 6) for Enterobacter cloacae. The endpoint PCR results showed 11 colonies positive for blaBIL (91.7%), 11 for blaSHV (91.7%), 11 for blaCTX (97.7%), 12 for blaDHA (100%), four for blaVIM (33.3%), two for blaOXA (16.7%), two for blaIMP (16.7%), one for blaKPC (8.3%), and one for blaTEM (8.3%) gen; all samples were negative for blaROB, blaCMY, blaP, blaCFX and blaLAP gene. The sequencing analysis revealed a specific genotype for Enterobacter cloacae (blaSHV-12, blaCTX-M-15, blaDHA-1, blaKPC-2); Serratia marcescens (blaSHV-1, blaCTX-M-3, blaDHA-1, blaVIM-2); Klebsiella pneumoniae (blaSHV-12, blaCTX-M-15, blaDHA-1); Serratia fonticola (blaSHV-12, blaVIM-1, blaDHA-1); and, Enterobacter aerogene (blaSHV-1, blaCTX-M-1, blaDHA-1, blaVIM-2, blaOXA-9). Our results indicate that beta-lactam-resistant bacteria have acquired integrons with a different number of genes that provide pan-resistance to beta-lactam antibiotics, including penicillins, oxacillins, cefalosporins, monobactams, carbapenems, and imipenems. | 2018 | 30477153 |
| 1215 | 19 | 0.9268 | The role of the plasmid-mediated fluoroquinolone resistance genes as resistance mechanisms in pediatric infections due to Enterobacterales. INTRODUCTION: Fluoroquinolones (FQs) are not commonly prescribed in children, yet the increasing incidence of multidrug-resistant (MDR) Enterobacterales (Ent) infections in this population often reveals FQ resistance. We sought to define the role of FQ resistance in the epidemiology of MDR Ent in children, with an overall goal to devise treatment and prevention strategies. METHODS: A case-control study of children (0-18 years) at three Chicago hospitals was performed. Cases had infections by FQ-susceptible, β-lactamase-producing (bla) Ent harboring a non- or low-level expression of PMFQR genes (PMFQS Ent). Controls had FQR infections due to bla Ent with expressed PMFQR genes (PMFQR Ent). We sought bla genes by PCR or DNA (BD Max Check-Points assay(®)) and PMFQR genes by PCR. We performed rep-PCR, MLST, and E. coli phylogenetic grouping. Whole genome sequencing was additionally performed on PMFQS Ent positive isolates. Demographics, comorbidities, and device, antibiotic, and healthcare exposures were evaluated. Predictors of infection were assessed. RESULTS: Of 170 β-lactamase-producing Ent isolates, 85 (50%) were FQS; 23 (27%) had PMFQR genes (PMFQS cases). Eighty-five (50%) were FQR; 53 (62%) had PMFQR genes (PMFQR controls). The median age for children with PMFQS Ent and PMFQR Ent was 4.3 and 6.2 years, respectively (p = NS). Of 23 PMFQS Ent, 56% were Klebsiella spp., and of 53 PMFQR Ent, 76% were E. coli. The most common bla and PMFQR genes detected in PMFQS Ent were bla (SHV ESBL) (44%) and oqxAB (57%), and the corresponding genes detected in PMFQR Ent were bla (CTX-M-1-group ESBL) (79%) and aac(6')-Ib-cr (83%). Whole genome sequencing of PMFQS Ent revealed the additional presence of mcr-9, a transferable polymyxin resistance gene, in 47% of isolates, along with multiple plasmids and mobile genetic elements propagating drug resistance. Multivariable regression analysis showed that children with PMFQS Ent infections were more likely to have hospital onset infection (OR 5.7, 95% CI 1.6-22) and isolates containing multiple bla genes (OR 3.8, 95% CI 1.1-14.5). The presence of invasive devices mediated the effects of healthcare setting in the final model. Differences in demographics, comorbidities, or antibiotic use were not found. CONCLUSIONS: Paradoxically, PMFQS Ent infections were often hospital onset and PMFQR Ent infections were community onset. PMFQS Ent commonly co-harbored multiple bla and PMFQR genes, and additional silent, yet transferrable antibiotic resistance genes such as mcr-9, affecting therapeutic options and suggesting the need to address infection prevention strategies to control spread. Control of PMFQS Ent infections will require validating community and healthcare-based sources and risk factors associated with acquisition. | 2023 | 37900312 |