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124700.9977Antibiotic 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.201323688522
125110.9977Biofilm 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.202539561392
129520.9977Phenotypic 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
133530.9977Prevalence of virulence factor, antibiotic resistance, and serotype genes of Pasteurella multocida strains isolated from pigs in Vietnam. AIM: The study was conducted to determine the prevalence and characterization of the Pasteurella multocida isolates from suspected pigs in Vietnam. MATERIALS AND METHODS: A total of 83 P. multocida strains were isolated from lung samples and nasal swabs collected from pigs associated with pneumonia, progressive atrophic rhinitis, or reproductive and respiratory symptoms. Isolates were subjected to multiplex polymerase chain reaction (PCR) for capsular typing, detection of virulence-associated genes and antibiotic resistance genes by PCR. The antimicrobial sensitivity profiles of the isolates were tested by disk diffusion method. RESULTS: All the isolates 83/83 (100%) were identified as P. multocida by PCR: serogroup A was obtained from 40/83 (48.19%), serogroup D was detected from 24/83 strains (28.91%), and serogroup B was found in 19/83 (22.35%) isolates. The presence of 14 virulence genes was reported including adhesins group (ptfA - 93.97%, pfhA - 93.97%, and fimA - 90.36%), iron acquisition (exbB - 100%, and exbD - 85.54%), hyaluronidase (pmHAS - 84.33%), and protectins (ompA - 56.62%, ompH 68.67%, and oma87 - 100%). The dermonecrotoxin toxA had low prevalence (19.28%). The antimicrobial susceptibility testing revealed that cephalexin, cefotaxime, ceftriaxone, ofloxacin, pefloxacin, ciprofloxacin, and enrofloxacin were the drugs most likely active against P. multocida while amoxicillin and tetracycline were inactive. The usage of PCR revealed that 63/83 isolates were carrying at least one of the drug resistance genes. CONCLUSION: Unlike other parts of the word, serotype B was prevalent among Vietnamese porcine P. multocida strains. The high antibiotic resistance detected among these isolates gives us an alert about the current state of imprudent antibiotic usage in controlling the pathogenic bacteria.202032636585
110740.9976Prevalence of plasmid-mediated quinolone resistance genes among ciprofloxacin-nonsusceptible Escherichia coli and Klebsiella pneumoniae isolated from blood cultures in Korea. OBJECTIVES: To analyze the prevalence of plasmid-mediated quinolone resistance (PMQR) determinants in ciprofloxacin-nonsusceptible Escherichia coli and Klebsiella pneumoniae isolated from patients at a tertiary care hospital in Korea. METHODS: A total of 102 nonduplicate isolates of ciprofloxacin-intermediate or ciprofloxacin-resistant E coli (n=80) and K pneumoniae (n=22) from blood cultures were obtained. The qnr (qnrA, qnrB, qnrS), aac(6')-Ib-cr, qepA and oqxAB genes were detected using polymerase chain reaction (PCR) and confirmed using direct sequencing. To determine whether the PMQR-positive plasmid was horizontally transferable, conjugation experiments were performed. RESULTS: Of the 102 isolates, 81 (79.4%) had one or more PMQR genes; these consisted of 59 (73.8%) E coli and 22 (100%) K pneumoniae isolates. The qnr genes were present in 15 isolates (14.7%): qnrB4 was detected in 10.8% and qnrS1 was detected in 3.9%. The aac(6')-Ib-cr, qepA and oqxAB genes were detected in 77.5%, 3.9% and 10.8%, respectively. In conjugation experiments, PMQR genes were successfully transferred from seven (8.6%) isolates. The range of minimum inhibitory concentrations of ciprofloxacin for these seven transconjugants increased to 0.5 mg/L to 1 mg/L, which was 16- to 33-fold that of the recipient E coli J53 bacteria. CONCLUSIONS: PMQR genes were highly prevalent among ciprofloxacin-nonsusceptible E coli and K pneumoniae from blood cultures in the authors' hospital. Therefore, it is necessary to monitor for the spread of PMQR genes of clinical isolates and to ensure careful antibiotic use in a hospital setting.201425285114
113350.9976High resistance to tetracycline and ciprofloxacin in bacteria isolated from poultry farms in Ibadan, Nigeria. INTRODUCTION: Resistance to ciprofloxacin and tetracycline is increasing in the food chain especially in E. coli strains and more worrisome will be occurrence of extended-spectrum beta-lactamase (ESBL) producers among ciprofloxacin- and tetracycline-resistant isolates. This study was undertaken to investigate the occurrence and mechanism of ciprofloxacin-, tetracycline- and ESBL-resistant bacteria in poultry in Ibadan, Nigeria. METHODOLOGY: Bacteria were isolated from poultry feces in two farms in Ibadan and identified by MALDI-TOF. Antibiotic susceptibility patterns of the isolates were determined by disc diffusion and Minimum Inhibitory Concentration (MIC) using Vitek-2 apparatus. Four tetracycline genes and six plasmids mediated quinolone resistance genes (PMQR) were investigated by PCR. Whole genome sequencing was done for strains that were ESBL producers. RESULTS: Bacterial strains (≥ 105 cfu/mL) were counted on ciprofloxacin and tetracycline supplemented plates. 106 bacteria from 14 different species were identified with high resistance to quinolones, tetracycline and trimethoprim. 49% of the strains were E. coli with 90% resistance for nalidixic acid, moxifloxacin (94%), ciprofloxacin (88%) levofloxacin (78%) and tetracycline (77%). The genes tetA, tetB, qnrB, qnrS and qepA were detected with 37%, 4%, 35%, 4% and 2% prevalence in E. coli respectively. Three ESBL-producing E. coli of the sequence type ST-6359 were found and harboured blaCTX-M-15 located in the chromosome, at the same insertion site. All the ESBL producers harboured mutations in gyrA (S83L/D87N/D678E) and parC (S80I). CONCLUSION: The observed high quinolones and tetracycline resistance with ESBL producers in this study calls for caution in the use of these antibiotics in poultry feeds.201831940298
129460.9975Isolation and detection of antibiotics resistance genes of Escherichia coli from broiler farms in Sukabumi, Indonesia. OBJECTIVE: This study aimed to isolate and identify Escherichia coli from broiler samples from Sukabumi, Indonesia. Also, antibiogram studies of the isolated bacteria were carried out considering the detection of the antibiotic resistance genes. MATERIALS AND METHODS: Cloaca swabs (n = 45) were collected from broilers in Sukabumi, Indonesia. Isolation and identification of E. coli were carried out according to standard bacteriological techniques and biochemical tests, followed by confirmation of the polymerase chain reaction targeting the uspA gene. Antibiotic sensitivity test, using several antibiotics [tetracycline (TE), oxytetracycline (OT), ampicillin (AMP), gentamicin (CN), nalidixic acid (NA), ciprofloxacin (CIP), enrofloxacin (ENR), chloramphenicol, and erythromycin] was carried out following the Kirby-Bauer disk diffusion method. Detection of antibiotic resistance coding genes was carried out by PCR using specific oligonucleotide primers. Statistical analysis was carried out with one-way analysis of variance. RESULTS: The results showed that 55.6% (25/45) of the samples were associated with the presence of E. coli. Antibiotic sensitivity test showed that the E. coli isolates were resistant to TE (88%; 22/25), OT (88%; 22/25), AMP (100%; 25/25), CN (64%; 16/25), NA (100%; 22/25), CIP (88%; 22/25), ENR (72%; 18/25), chloramphenicol (0%; 0/25), and erythromycin (92%; 23/25). On the other hand, the antibiotic resistance coding genes were tetA (86.4%; 19/22), blaTEM (100%; 25/25), aac(3)-IV (0%; 0/16), gyrA (100%; 25/25), and ermB (13%; 3/23). It was found that chloramphenicol is markedly different from other antibiotic treatment groups. CONCLUSION: Escherichia coli was successfully isolated from cloacal swabs of broiler in Sukabumi, Indonesia. The bacteria were resistant to TE, OT, AMP, CN, NA, CIP, ENR, and erythromycin. Chloramphenicol was more sensitive and effective than other antibiotics in inhibiting the growth of E. coli. The antibiotic resistance genes detected were tetA, blaTEM, gyrA, and ermB.202133860017
145270.9975Characterization of carbapenem-resistant Gram-negative bacteria from Tamil Nadu. Carbapenem resistance is disseminating worldwide among Gram-negative bacteria. The aim of this study was to identify carbapenem-resistance level and to determine the mechanism of carbapenem resistance among clinical isolates from two centres in Tamil Nadu. In the present study, a total of 93 Gram-negative isolates, which is found to be resistant to carbapenem by disk diffusion test in two centres, were included. All isolates are identified at species level by 16S rRNA sequencing. Minimal inhibitory concentrations (MICs) of isolates for Meropenem were tested by agar dilution method. Presence of blaOXA, blaNDM, blaVIM, blaIMP and blaKPC genes was tested by PCR in all isolates. Amplicons were sequenced for confirmation of the genes. Among 93 isolates, 48 (%52) were Escherichia coli, 10 (%11) Klebsiella pneumoniae, nine (%10) Pseudomonas aeruginosa. Minimal inhibitory concentration results showed that of 93 suspected carbapenem-resistant isolates, 27 had meropenem MICs ≥ 2 μg/ml. The MIC range, MIC50 and MIC90 were < 0.06 to >128 μg/ml, 0.12 and 16 μg/ml, respectively. Fig. 1 . Among meropenem-resistant isolates, E. coli were the most common (9/48, 22%), followed by K. pneumoniae (7/9, 77%), P. aeruginosa (6/10, 60%), Acinetobacter baumannii (2/2, 100%), Enterobacter hormaechei (2/3, 67%) and one Providencia rettgeri (1/1, 100%). PCR results showed that 16 of 93 carried blaNDM, three oxa181, and one imp4. Among blaNDM carriers, nine were E. coli, four Klebsiella pneumoniae, two E. hormaechei and one P. rettgeri. Three K. pneumoniae were OXA-181 carriers. The only imp4 carrier was P. aeruginosa. A total of seven carbapenem-resistant isolates were negatives by PCR for the genes studied. All carbapenem-resistance gene-positive isolates had meropenem MICs >2 μg/ml. Our results confirm the dissemination of NDM and emergence of OXA-181 beta-lactamase among Gram-negative bacteria in South India. This study showed the emergence of NDM producer in clinical isolates of E. hormaechei and P. rettgeri in India.201626198414
145480.9975OCCURRENCE 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.202337010165
129390.9975Antibiotic resistance in faecal bacteria (Escherichia coli, Enterococcus spp.) in feral pigeons. AIMS: To determine the presence of antibiotic-resistant faecal Escherichia coli and Enterococcus spp. in feral pigeons (Columba livia forma domestica) in the Czech Republic. METHODS AND RESULTS: Cloacal swabs of feral pigeons collected in the city of Brno in 2006 were cultivated for antibiotic-resistant E. coli. Resistance genes, class 1 and 2 integrons, and gene cassettes were detected in resistant isolates by polymerase chain reaction (PCR). The samples were also cultivated for enterococci. Species status of enterococci isolates was determined using repetitive extragenic palindromic-PCR. Resistance genes were detected in resistant enterococci by PCR. E. coli isolates were found in 203 of 247 pigeon samples. Antibiotic resistance was recorded in three (1·5%, n(E. coli) =203) isolates. Using agar containing ciprofloxacin, 12 (5%, n(samples) =247) E. coli strains resistant to ciprofloxacin were isolated. No ESBL-producing E. coli isolates were detected. A total of 143 enterococci were isolated: Ent. faecalis (36 isolates), Ent. faecium (27), Ent. durans (19), Ent. hirae (17), Ent. mundtii (17), Ent. gallinarum (12), Ent. casseliflavus (12) and Ent. columbae (3). Resistance to one to four antibiotics was detected in 45 (31%) isolates. Resistances were determined by tetK, tetL, tetM, tetO, aac(6')aph(2''), ant(4')-Ia, aph(3')-IIIa, ermB, pbp5, vanA and vanC1 genes. CONCLUSIONS: Antibiotic-resistant E. coli and Enterococcus spp. occurred in feral pigeons in various prevalences. SIGNIFICANCE AND IMPACT OF THE STUDY: Feral pigeon should be considered a risk species for spreading in the environment antimicrobial resistant E. coli and enterococci.201020602656
1457100.9975Detection 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.202133562276
1309110.9975Phenotypic and genotypic antimicrobial resistance patterns of Escherichia coli isolated from dairy cows with mastitis. Pulsed field gel electrophoresis (PFGE) patterns, susceptibility to 26 antimicrobial agents used in veterinary and human medicine, and prevalence of antimicrobial resistance genes of Escherichia coli isolated from cows with mastitis were evaluated. Among 135 E. coli isolates, PFGE analysis revealed 85 different genetic patterns. All E. coli were resistant to two or more antimicrobials in different combinations. Most E. coli were resistant to antimicrobials used in veterinary medicine including ampicillin (98.4%, >or=32 microg/ml) and many E. coli were resistant to streptomycin (40.3%, >or=64 microg/ml), sulfisoxazole (34.1%, >or=512 microg/ml), and tetracycline (24.8%, >or=16 microg/ml). Most E. coli were resistant to antimicrobials used in human medicine including aztreonam (97.7%, >or=32 microg/ml) and cefaclor (89.9%, >or=32 microg/ml). Some E. coli were resistant to nitrofurantoin (38%, >or=128 microg/ml), cefuroxime (22.5%, >or=32 microg/ml), fosfomycin (17.8%, >or=256 microg/ml). All E. coli were susceptible to ciprofloxacin and cinoxacin. Almost 97% (123 of 127) of ampicillin-resistant isolates carried ampC. Eleven of 52 (21.2%) streptomycin-resistant isolates carried strA, strB and aadA together and 29 streptomycin-resistant isolates (55.8%) carried aadA alone. Among 44 sulfisoxazole-resistant E. coli, 1 isolate (2.3%) carried both sulI and sulII, 12 (27.3%) carried sulI and 10 (22.7%) isolates carried sulII. Among 32 tetracycline-resistant isolates, 14 (43.8%) carried both tetA and tetC and 14 (43.8%) carried tetC. Results of this study demonstrated that E. coli from cows with mastitis were genotypically different, multidrug resistant and carried multiple resistance genes. These bacteria can be a reservoir for antimicrobial resistance genes and can play a role in the dissemination of antimicrobial resistance genes to other pathogenic and commensal bacteria in the dairy farm environment.200717544234
1236120.9975Molecular 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.201121338385
1467130.9975Detection of bla (CTX-M15) and bla (OXA-48) genes in Gram-negative isolates from neonatal sepsis in central of Iran. BACKGROUND AND OBJECTIVES: The aim of this study was to determine the prevalence of neonatal sepsis with a focus on antibiotic resistance and the frequency of the bla (CTX-M-15) and bla (OXA-48) genes in Gram-negative isolates. MATERIALS AND METHODS: A total of 108 Umbilical Cord Blood (UCB) and 153 peripheral blood samples were cultured via BACTEC from May 2017 to June 2018. The bacterial isolates were identified using phenotypic and genotypic analyses. The antibiotic susceptibility profile of the isolates was determined by disk diffusion. PCR was used to determine the frequency of β-lactamase genes. RESULTS: Among the 153 infants, 21 (13.7%) proved positive for sepsis. Escherichia coli, Staphylococcus epidermidis and Klebsiella pneumoniae were the most frequent isolates in the peripheral blood cultures. E. coli and Stenotrophomonas maltophilia were isolated from two UCB cultures. The highest resistance among the Gram-positive strains was to cefixime, ceftriaxone, cefotaxime and clindamycin. In the Gram-negative bacteria the highest rates of resistance were to ampicillin (91.7%). The frequency of bla (OXA-48) and bla (CTX-M-15) genes was 25% and 50%, respectively. CONCLUSION: The high antibiotic resistance among the isolates reveals the importance of monitoring antibiotic consumption and improving control standards in the health care system, especially in neonatal wards.201931719958
1249140.9974High-Level Resistance to Aminoglycosides due to 16S rRNA Methylation in Enterobacteriaceae Isolates. Introduction: High-level aminoglycoside resistance due to methylase genes has been reported in several countries. The purpose of this study was to investigate the diversity of the genes encoding 16S rRNA methylase and their association with resistance phenotype in Enterobacteriacae isolates. Materials and Methods: Based on sampling size formula, from February to August 2014, a total of 307 clinical Enterobacteriaceae isolates were collected from five hospitals in northwest Iran. The disk diffusion method for amikacin, gentamicin, tobramycin, kanamycin, and streptomycin, as well as the minimum inhibitory concentration (MIC) for aminoglycosides (except streptomycin), was used. Six 16S rRNA methylase genes (armA, npmA, and rmtA-D) were screened by PCR and sequencing assays. Results: In this study, 220 (71.7%) of 307 isolates were aminoglycoside resistant and 40 isolates (18.2%, 40/220) were positive for methylase genes. The frequency of armA, rmtC, npmA, rmtB, and rmtA genes was 9.5%, 4.5%, 3.6%, 2.3%, and 1%, respectively. The rmtD gene was not detected in the tested bacteria. Sixty percent of positive methylase gene isolates displayed high-level resistance (MIC ≥512 μg/mL to amikacin and kanamycin; and MIC ≥128 μg/mL to gentamicin and tobramycin). Conclusions: The prevalence of resistance to aminoglycoside in Iran is high. Furthermore, there is a statistically significant association between amikacin and kanamycin resistance with the presence of rmtC and rmtB genes.201931211656
1311150.9974Prevalence and Molecular Characterization of Antimicrobial Resistance in Escherichia coli Isolated from Raw Milk and Raw Milk Cheese in Egypt. The goal of this study was to examine antimicrobial resistance and characterize the implicated genes in 222 isolates of Escherichia coli from 187 samples of raw milk and the two most popular cheeses in Egypt. E. coli isolates were tested for susceptibility to 12 antimicrobials by a disk diffusion method. Among the 222 E. coli isolates, 66 (29.7%) were resistant to one or more antimicrobials, and half of these resistant isolates showed a multidrug resistance phenotype (resistance to at least three different drug classes). The resistance traits were observed to tetracycline (27.5%), ampicillin (18.9%), streptomycin (18.5%), sulfamethoxazole-trimethoprim (11.3%), cefotaxime (4.5%), kanamycin (4.1%), ceftazidime (3.6%), chloramphenicol (2.3%), nalidixic acid (1.8%), and ciprofloxacin (1.4%). No resistance to fosfomycin and imipenem was observed. Tetracycline resistance genes tetA, tetB, and tetD were detected in 53 isolates, 9 isolates, and 1 isolate, respectively, but tetC was not detected. Aminoglycoside resistance genes strA, strB, aadA, and aphA1 were detected in 41, 41, 11, and 9 isolates, respectively. Sulfonamide resistance genes sul1, sul2, and sul3 were detected in 7, 25, and 3 isolates, respectively. Of 42 ampicillin-resistant isolates, bla(TEM), bla(CTX-M), and bla(SHV) were detected in 40, 9, and 3 isolates, respectively, and 10 (23.8%) ampicillin-resistant isolates were found to produce extended-spectrum β-lactamase. Each bla gene of extended-spectrum β-lactamase-producing E. coli was further subtyped to be bla(CTX-M-15), bla(CTX-M-104), bla(TEM-1), and bla(SHV-12). The class 1 integron was also detected in 28 resistant isolates, and three different patterns were obtained by PCR-restriction fragment length polymorphism. Sequencing analysis of the variable region revealed that four isolates had dfrA12/orfF/aadA2, two had aadA22, and one had dfrA1/aadA1. These data suggest that antimicrobial-resistant E. coli are widely distributed in the milk production and processing environment in Egypt and may play a role in dissemination of antimicrobial resistance to other pathogenic and commensal bacteria.201829323530
1125160.9974Detection of emerging antibiotic resistance in bacteria isolated from subclinical mastitis in cattle in West Bengal. AIM: The aim of this work was to detect antibiotic resistance in Gram-negative bacteria isolated from subclinical mastitis in cattle in West Bengal. MATERIALS AND METHODS: The milk samples were collected from the cattle suffering with subclinical mastitis in West Bengal. The milk samples were inoculated into the nutrient broth and incubated at 37°C. On the next day, the growth was transferred into nutrient agar and MacConkey agar. All the pure cultures obtained from nutrient agar slant were subjected to Gram-staining and standard biochemical tests. All the bacterial isolates were tested in vitro for their sensitivity to different antibiotics commonly used in veterinary practices. All Gram-negative isolates including positive control were subjected to polymerase chain reaction (PCR) for detection of bla(CTX-M), bla(TEM), bla(SHV), bla(VIM), tetA, tetB, tetC, and tetM genes considered for extended-spectrum β-lactamase (ESBL), metallo-β-lactamase, and tetracycline resistance. RESULTS: In total, 50 Gram-negative organisms (Escherichia coli, Proteus, Pseudomonas, Klebsiella, and Enterobacter) were isolated from milk samples of subclinical mastitis infected cattle. Among these Gram-negative isolates, 48% (24/50) were found either ESBL producing or tetracycline resistant. Out of total 50 Gram-negative isolates, bla(CTX-M) was detected in 18 (36%) isolates, and 6 (12%) harbored bla(TEM) genes in PCR. None of the isolates carried bla(SHV) genes. Further, in this study, 5 (10%) isolates harbored tet(A) gene, and 8 (16%) isolates carried tet(B) gene. No tet(C) gene was detected from the isolates. CONCLUSION: This study showed emerging trend of antibiotic-resistant Gram-negative bacteria associated with subclinical mastitis in cattle in West Bengal, India.201728620255
1233170.9974Prevalence, 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.202031532307
2185180.9974Isolation of multidrug-resistant Escherichia coli, Staphylococcus spp., and Streptococcus spp. from dogs in Chattogram Metropolitan Area, Bangladesh. OBJECTIVES: Antibacterial resistance is a great concern in human and food animal medicine, and it poses a significant concern in pet animals like dogs. This cross-sectional study was conducted to evaluate the antimicrobial resistance pattern of Escherichia coli, Staphylococcus spp., and Streptococcus spp. along with the carryover of some resistance genes in E. coli from dogs in the Chattogram metropolitan area, Bangladesh. MATERIALS AND METHODS: Rectal swab (n = 50), nasal swab (n = 50), and skin swab (n = 50) samples were collected from dogs having respiratory infections, skin infections, and/or enteritis, respectively. Three types of bacteria were identified and isolated by conventional bacteriological techniques and biochemical tests. Antimicrobial susceptibility testing was carried out against 12 antimicrobials by disk diffusion methods. Six resistance genes, namely bla (TEM), bla (CTX-M), tetA, tetB, Sul-I, and Sul-II, were screened for phenotypically resistant E. coli isolates by the polymerase chain reaction. RESULTS: A total of 39 (78%) E. coli, 25 (50%) Staphylococcus spp., and 24 (48%) Streptococcus spp. isolates were isolated from the rectal swab, nasal swab, and skin swab samples, respectively. In the cultural sensitivity test, the E. coli isolates showed resistance to ceftriaxone (79%) and sulfamethoxazole/trimethoprim (64%). Doxycycline (80%) demonstrated the highest resistance among Staphylococcus isolates, followed by sulfamethoxazole/trimethoprim (60%). Streptococcus isolates showed the highest resistance to penicillin (63%), followed by ceftriaxone (54%), while no isolate showed resistance to gentamycin. The prevalence of bla (TEM), bla (CTX-M), tetA, tetB, Sul-I, and Sul-II genes in phenotypically resistant E. coli isolates were 100%, 61.29%, 100%, 8.33%, 56%, and 72%, respectively. CONCLUSIONS: Spillover of such multidrug-resistant bacteria and resistance genes from pet dogs pose a serious public health risk.202033409311
1252190.9974Fluoroquinolone 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.202236453351