# | Rank | Similarity | Title + Abs. | Year | PMID |
|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | 5 |
| 1226 | 0 | 0.9944 | 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 |
| 1233 | 1 | 0.9942 | 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 | 2 | 0.9939 | 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 |
| 1454 | 3 | 0.9936 | OCCURRENCE OF AMINOGLYCOSIDES RESISTANCE GENES ACC(6)-IB AND ACC(3)-II AMONG GRAM-NEGATIVE ISOLATES CAUSING URINARY TRACT INFECTION IN PEDIATRIC PATIENTS, NAJAF, IRAQ. OBJECTIVE: The aim: The aim of the study was to detect the antimicrobial susceptibility patterns and frequency of aminoglycosides resistance genes of Gram-negative bacteria isolated from pediatric patient with UTI. PATIENTS AND METHODS: Materials and methods: The study has been performed with a total of 500 urine specimens collected from pediatric patients under the age of 18 year suspected with UTI, admitted to hospitals in Al-Najaf province/Iraq during the period from November 2018 to March 2019. RESULTS: Results: A total of 500 urine specimens had been tested, 120 (24%) had signifficant bacteriuria, while there 380 (76%) had non-signi!cant bacteriuria. Escherichia coli represent about 70 (68.2%) followed by followed by 23 (22.5%) K. pneumoniae, 5 (4.9%) P. aeruginosa, 2 (1.9%) Proteus spp., 1 (0.9%) Enterobacter spp. and 1 (0.9%) Oligella uratolytic. The antimicrobial susceptibility profile of 102 Gram-negative isolates, revealed that 59 (58%) were multidrug resistant (MDR) and 38(37%) were extensive drug resistant (XDR). The PCR results of aminoglycosides resistance showing that 23 (74.1%) Gram-negative isolates had acc(6')-Ib gene and 12 (38.7%) Gram-negative isolates acc(3')-II gene. CONCLUSION: Conclusions: A high frequency of multi-drug resistance and extensive-drug resistance of isolates were recognized, and an alarming percentage of amino-glycosides resistance to acc(6')-Ib and acc(3')-II. | 2023 | 37010165 |
| 1252 | 4 | 0.9935 | Fluoroquinolone resistance in bacterial isolates from ocular infections: Trend in antibiotic susceptibility patterns between 2005-2020. PURPOSE: To assess the fluoroquinolone resistance pattern and trends among bacterial isolates from ocular infections over a 16-year period and explore alternative antibiotics in fluoroquinolone-resistant strains. METHODS: In this retrospective, longitudinal study, the microbiology laboratory records of patients with different ocular infections diagnosed at an eye institute in central India from 2005-2020 were reviewed to determine the pattern of fluoroquinolone (ciprofloxacin, ofloxacin, gatifloxacin, and moxifloxacin) resistance. Antibiotic susceptibility testing was done using the Kirby-Bauer disc diffusion method. RESULTS: In 725 Gram-positive bacteria, the resistance of ciprofloxacin, ofloxacin, gatifloxacin, and moxifloxacin was 55.9% (95% confidence interval [CI]: 52.2 - 59.6), 42.7% (95% CI: 39.0 - 46.4), 47.6% (95% CI: 43.9 - 51.3), and 45.6% (95% CI: 41.7-49.5), respectively. In 266 Gram-negative bacteria, the resistance of ciprofloxacin, ofloxacin, gatifloxacin, and moxifloxacin was 57.9% (95% CI: 51.9 - 63.9), 56.0% (95% CI: 49.7 - 62.1), 59.9% (95% CI: 53.8 - 66.0), and 74.3% (95% CI: 68.3 - 80.2), respectively. A declining trend in resistance to ciprofloxacin (P < 0.001), ofloxacin (P < 0.001), and moxifloxacin (P < 0.001) was seen in Gram-positive bacteria, whereas a reduction in resistance to only moxifloxacin (P = 0.04) was seen in Gram-negative bacteria. In fluoroquinolone-resistant Gram-positive bacteria, cefuroxime exhibited the highest susceptibility, whereas in fluoroquinolone-resistant Gram-negative bacteria, colistin exhibited the highest susceptibility. CONCLUSION: Fluoroquinolone resistance was high among bacteria from ocular infections in central India, but a declining trend in resistance to some of the fluoroquinolones was observed in recent times. Cefuroxime and colistin emerged as alternatives in fluoroquinolone-resistant Gram-positive and Gram-negative bacterial infections, respectively. | 2022 | 36453351 |
| 1487 | 5 | 0.9933 | Potential impact of a microarray-based nucleic acid assay for rapid detection of Gram-negative bacteria and resistance markers in positive blood cultures. We evaluated the Verigene Gram-negative blood culture (BC-GN) test, a microarray that detects Gram-negative bacteria and several resistance genes. A total of 102 positive blood cultures were tested, and the BC-GN test correctly identified 97.9% of the isolates within its panel. Resistance genes (CTX-M, KPC, VIM, and OXA genes) were detected in 29.8% of the isolates, with positive predictive values of 95.8% (95% confidence interval [CI], 87.7% to 98.9%) in Enterobacteriaceae and 100% (95% CI, 75.9% to 100%) in Pseudomonas aeruginosa and negative predictive values of 100% (95% CI, 93.9% to 100%) and 78.6% (95% CI, 51.0% to 93.6%), respectively. | 2014 | 24478405 |
| 1421 | 6 | 0.9933 | 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 |
| 1411 | 7 | 0.9933 | 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 |
| 1412 | 8 | 0.9932 | 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 |
| 1247 | 9 | 0.9932 | Antibiotic resistance determinants of multidrug-resistant Acinetobacter baumannii clinical isolates in Algeria. Antibiotic susceptibility testing was performed on 71 Acinetobacter baumannii clinical isolates, and presence of antibiotic resistance genes was screened for by PCR amplification and sequencing. Resistance rates were very high for aminoglycosides (22-80%), fluoroquinolones (>90%), and cephalosporins (>90%) but remained low for rifampin (2.8%) or null for colistin. Antibiotic resistance encoding genes detected were as follows: blaTEM-128 gene (74.6%), aph(3')-VI (50.7 %), aadA (63.4%), ant(2″)-I (14.1%), aac(3)-Ia (91.1%), aac(6')-Ib (4.2%), mutation Ser83Leu in gyrA (94.4%), double mutations Ser83Leu and Ser80Leu (or Ser84Leu) in gyrA and parC (69.0%), and mutation I581N in RRDR of the rpoB gene. | 2013 | 23688522 |
| 1455 | 10 | 0.9931 | 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 |
| 1451 | 11 | 0.9931 | 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 |
| 1295 | 12 | 0.9931 | Phenotypic 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. | 2009 | 19168331 |
| 1417 | 13 | 0.9931 | 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 |
| 1251 | 14 | 0.9930 | Biofilm Formation and Plasmid-Mediated Quinolone Resistance Genes at Varying Quinolone Inhibitory Concentrations in Quinolone-Resistant Bacteria Superinfecting COVID-19 Inpatients. The likelihood of antimicrobial failure in COVID-19 patients with bacterial superinfection arises from both phenotypic (biofilms) and genotypic mechanisms. This cross-sectional study aimed to determine the inhibitory concentrations of quinolones-nalidixic acid, norfloxacin, ciprofloxacin, ofloxacin, and levofloxacin-in biofilm formers (minimum biofilm inhibitory concentration [MBIC]) and nonformers (minimum inhibitory concentration [MIC]) and correlate inhibitory concentrations with plasmid-mediated quinolone resistance (PMQR) genes in quinolone-resistant bacteria isolated from COVID-19 inpatients. Quinolone-resistant bacteria (n = 193), verified through disc diffusion, were tested for quinolone inhibitory concentrations using broth microdilution and biofilm formation using microtiter plate methods. The polymerase chain reaction was used to detect PMQR genes. Study variables were analyzed using SPSS v.17.0, with a significance level set at P <0.05. MIC-to-MBIC median fold increases for ciprofloxacin, ofloxacin, and levofloxacin were 128 (2-8,192), 64 (4-1,024), and 32 (4-512) in gram-positive cocci (GPC, n = 43), respectively, whereas they were 32 (4-8,192), 32 (4-2,048), and 16 (2-1,024) in fermentative gram-negative bacilli (F-GNB, n = 126) and 16 (4-4,096), 64 (2-64), and 16 (8-512) in nonfermentative gram-negative bacilli (NF-GNB, n = 24). In biofilm-forming F-GNB and NF-GNB, qnrB (10/32 versus 3/10), aac(6')-Ib-cr (10/32 versus 4/10), and qnrS (9/32 versus 0/10) genes were detected. A 32-fold median increase in the MIC-to-MBIC of ciprofloxacin was significantly (P <0.05) associated with qnrA in F-GNB and qnrS in NF-GNB. Biofilms formed by F-GNB and NF-GNB were significantly associated with the aac(6')-Ib-cr and qnrS genes, respectively. Nearly one-third of the superinfecting bacteria in COVID-19 patients formed biofilms and had at least one PMQR gene, thus increasing the need for quinolones at higher inhibitory concentrations. | 2025 | 39561392 |
| 1457 | 15 | 0.9930 | Detection of TEM and CTX-M Genes in Escherichia coli Isolated from Clinical Specimens at Tertiary Care Heart Hospital, Kathmandu, Nepal. BACKGROUND: Antimicrobial resistance (AMR) among Gram-negative pathogens, predominantly ESBL-producing clinical isolates, are increasing worldwide. The main aim of this study was to determine the prevalence of ESBL-producing clinical isolates, their antibiogram, and the frequency of ESBL genes (bla(TEM) and bla(CTX-M)) in the clinical samples from patients. METHODS: A total of 1065 clinical specimens from patients suspected of heart infections were collected between February and August 2019. Bacterial isolates were identified on colony morphology and biochemical properties. Thus, obtained clinical isolates were screened for antimicrobial susceptibility testing (AST) using modified Kirby-Bauer disk diffusion method, while ESBL producers were identified by using a combination disk diffusion method. ESBL positive isolates were further assessed using conventional polymerase chain reaction (PCR) to detect the ESBL genes bla(TEM) and bla(CTX-M). RESULTS: Out of 1065 clinical specimens, 17.8% (190/1065) showed bacterial growth. Among 190 bacterial isolates, 57.4% (109/190) were Gram-negative bacteria. Among 109 Gram-negative bacteria, 40.3% (44/109) were E. coli, and 30.2% (33/109) were K. pneumoniae. In AST, 57.7% (n = 63) Gram-negative bacterial isolates were resistant to ampicillin and 47.7% (n = 52) were resistant to nalidixic acid. Over half of the isolates (51.3%; 56/109) were multidrug resistant (MDR). Of 44 E. coli, 27.3% (12/44) were ESBL producers. Among ESBL producer E. coli isolates, 58.4% (7/12) tested positive for the bla(CTX-M) gene and 41.6% (5/12) tested positive for the bla(TEM) gene. CONCLUSION: Half of the Gram-negative bacteria in our study were MDR. Routine identification of an infectious agent followed by AST is critical to optimize the treatment and prevent antimicrobial resistance. | 2021 | 33562276 |
| 1236 | 16 | 0.9929 | 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 |
| 1456 | 17 | 0.9929 | Resistance and Co-Resistance of Metallo-Beta-Lactamase Genes in Diarrheal and Urinary-Tract Pathogens in Bangladesh. Carbapenems are the antibiotics of choice for treating multidrug-resistant bacterial infections. Metallo-β-lactamases (MBLs) are carbapenemases capable of hydrolyzing nearly all therapeutically available beta-lactam antibiotics. Consequently, this research assessed the distribution of two MBL genes and three β-lactamases and their associated phenotypic resistance in diarrheal and urinary-tract infections (UTIs) to guide future policies. Samples were collected through a cross-sectional study, and β-lactamase genes were detected via PCR. A total of 228 diarrheal bacteria were isolated from 240 samples. The most predominant pathogens were Escherichia coli (32%) and Klebsiella spp. (7%). Phenotypic resistance to amoxicillin-clavulanic acid, aztreonam, cefuroxime, cefixime, cefepime, imipenem, meropenem, gentamicin, netilmicin, and amikacin was 50.4%, 65.6%, 66.8%, 80.5%, 54.4%, 41.6%, 25.7%, 41.2%, 37.2%, and 42.9%, respectively. A total of 142 UTI pathogens were identified from 150 urine samples. Klebsiella spp. (39%) and Escherichia coli (24%) were the major pathogens isolated. Phenotypic resistance to amoxicillin-clavulanic acid, aztreonam, cefuroxime, cefixime, cefepime, imipenem, meropenem, gentamicin, netilmicin, and amikacin was 93.7%, 75.0%, 91.5%, 93.7%, 88.0%, 72.5%, 13.6%, 44.4%, 71.1%, and 43%, respectively. Twenty-four diarrheal isolates carried blaNDM-1 or blaVIM genes. The overall MBL gene prevalence was 10.5%. Thirty-six UTI pathogens carried either blaNDM-1 or blaVIM genes (25.4%). Seven isolates carried both blaNDM-1 and blaVIM genes. MBL genes were strongly associated with phenotypic carbapenem and other β-lactam antibiotic resistance. blaOXA imparted significantly higher phenotypic resistance to β-lactam antibiotics. Active surveillance and stewardship programs are urgently needed to reduce carbapenem resistance in Bangladesh. | 2024 | 39203431 |
| 1440 | 18 | 0.9929 | High prevalence of carbapenem-resistant Escherichia coli ST410 from clinical isolates in Weifang, China. The objective of our work is to identify antimicrobial-resistance genes and to analyze clonality of carbapenem-resistant Escherichia coli. A total of 75 carbapenem-resistant E. coli (CREco) strains were isolated in a Chinese hospital from January 2021 to May 2023. The antibiotic susceptibility testing was conducted by BD PhoenixTM M50 System and Kirby-Bauer disk diffusion method. Whole-genome sequencing was performed on Illumina NovaSeq 6000 platform. Antimicrobial resistance genes were identified based on NCBI with ABRicate 0.8. Multilocus sequence typing (MLST) analysis for CREco was performed. Among the 75 CREco strains in this study, the most of them were isolated from urine samples (n = 20, 26.67%) at the intensive care unit (n = 14, 18.67%). Among the detected carbapenem resistance genes, blaNDM-5 was the most prevalent (n = 57, 76.00%), followed by blaNDM-4 (n = 3, 4.00%), blaNDM-9 (n = 3, 4.00%), and blaNDM-1 (n = 2, 2.67%). In addition, the colistin resistance gene mcr-1.1 (n = 11, 14.67%) and the tigecycline resistance gene tetX4 (n = 2, 2.67%) were also detected. The results of MLST revealed 25 sequence types (STs), and ST410 (n = 17) was the dominant clone. Other major STs included ST167 (n = 12), ST156 (n = 10), ST361 (n = 5), and ST101 (n = 4). Overall, CREco strains exhibited a high-level resistance rate to commonly used antimicrobial agents, and the most of them carried various NDM-coding genes, with blaNDM-5 being the predominant type. In this study, we demonstrated the diversity of carbapenem-resistant E. coli; however, the major clone was ST410. These results also show the dissemination of different clones of carbapenem-resistant E. coli. | 2025 | 40531574 |
| 1224 | 19 | 0.9928 | Prevalence, antibiotic resistance patterns and molecular characterization of Escherichia coli from Austrian sandpits. The aim was to determine the prevalence of E. coli and coliform bacteria in playground sand of all public children's sandpits in Graz (n = 45), Austria, and to assess the frequency of antimicrobial resistance in E. coli. Molecular characterization included the discrimination of O-serotypes and H-antigens and the determination of virulence and resistance genes, using a microarray technology. E. coli isolates were tested for susceptibility to a set of antibiotics by VITEK2 system and disk diffusion method. In total, 22 (49%) and 44 (98%) sandpits were positive for E. coli and coliform bacteria. Median concentrations of E. coli and coliform bacteria in the sand samples were: 2.6 × 10(4) CFU/100 g and 3.0 × 10(5) CFU/100 g. Resistance rates were: ampicillin, 12.5%; piperacillin, 10.4%; amoxicillin/clavulanic acid, 9.4%; cotrimoxazole, 6.3%; tetracycline, 6.3%; piperacillin/tazobactam, 5.2%. No ESBL- or carbapenemase-producing isolates were found. The most prevalent serogroups were O15, O6 and O4. Isolates harbored 0 up to 16 different virulence genes. | 2014 | 25089889 |