The Antibiotic Resistance Pattern and Prevalence of blaTEM, blaSHV, blaCTX-M, blaPSE-1, sipB/C, and cmlA/tetR Genes in Salmonella typhimurium Isolated from Children with Diarrhea in Tabriz, Iran

2021 ◽  
Vol In Press (In Press) ◽  
Author(s):  
Abolfazl Jafari Sales ◽  
Sara Naebi ◽  
Rozita Nasiri ◽  
Hossein Bannazadeh-Baghi

Background: Salmonella gastroenteritis is a global health concern. Recently, increased resistance to Salmonella typhimurium has been reported in several countries. Objectives: The present study aimed to evaluate the prevalence of blaTEM, blaSHV, blaCTX-M, blaPSE-1, sipB/C, and cmlA/tetR genes in S. typhimurium isolates and determine their antibiotic resistance. Methods: This cross-sectional descriptive study was conducted on 110 fecal samples, which were collected from the patients referred to the hospitals and medical centers in Tabriz, Iran during eight months. After phenotypic identification, the antibiogram test and double-disc synergy test were performed on the isolates. Following that, the prevalence of resistance genes was evaluated using multiplex PCR and specific primers. Results: Out of 110 fecal samples, 26 samples (23.63%) were positive for S. typhimurium. The highest resistance of the isolates was against ceftazidime, cefotaxime, amikacin, and tetracycline (100%), and the lowest resistance was against imipenem (3.85%) and nalidixic acid (7.69%). In total, 15 S. typhimurium isolates (57.69%) were positive for the extended-spectrum beta-lactamases. In addition, the most common resistance genes in the isolates were cmlA/tetR (38.46%), blaTEM (34.61%), and blaCTX-M (26.92%). Four isolates (15.38%) carried sipB, three isolates (11.53%) contained blaSHV, and two isolates (7.69%) carried blaPSE-1. Conclusions: The obtained results indicated the high prevalence of antibiotic-resistant S. typhimurium. Therefore, the identification of resistance genes is an important strategy for identifying and counteracting antibiotic resistance.

2021 ◽  
Vol In Press (In Press) ◽  
Author(s):  
Abolfazl Jafari Sales ◽  
Sara Naebi ◽  
Hossein Bannazadeh-Baghi ◽  
Morteza Saki

Background: Nowadays, the resistance of pathogenic bacteria to antibiotics has become a global problem. Acinetobacter baumannii is an important opportunistic nosocomial pathogen. Acinetobacter baumannii plays a significant role in antibiotic resistance. Objectives: The purpose of this study was to investigate the prevalence of the blaOXA-51, blaNDM, blaVIM, blaPER, blaVEB, blaCTX-M, tetA and tetB genes and antibiotic resistance pattern of A. baumannii isolated from hospitals in Tabriz city, Iran. Methods: This study was descriptive cross-sectional research, performed on 129 isolates of Acinetobacter from different clinical specimens. The Isolates were identified using standard laboratory methods and culture in selective mediums. The antibiotic resistance pattern of isolates was also determined by the Kirby-Bauer disk diffusion susceptibility test. Phenotypic and genotypic detection of blaOXA-51, blaNDM, blaVIM, blaPER, blaVEB, blaCTX-M, tetA and tetB genes in the isolates was carried out by a combined disk test (CDT) and polymerase chain reaction (PCR), respectively. Results: The highest resistance of isolates was determined to cefotaxime (100%) and ceftazidime (100%). The results of CDT showed that 14 (12.96%) isolates could produce extended-spectrum Beta-lactamases (ESBLs). However, the PCR results blaOXA-51, blaNDM, blaVIM, blaPER, blaVEB, blaCTX-M, tetA and tetB genes showed that these genes were in 100%, 18.51%, 16.66%, 32.40%, 16.66%, 31.48%, 32.40% and 21.29% of isolates, respectively. Conclusions: Due to the high prevalence of antimicrobial resistance in strains, rapid and timely detection of antibiotic-resistant A. baumannii strains is necessary for the selection of an appropriate therapeutic approach and prevention of their prevalence.


Extended spectrum beta-lactamases (ESBL) in Klebsiella pneumoniae isolates have led to increased antibiotic resistance and mortality in patients. Therefore, the present study was performed to investigate the susceptibility and antibiotic resistance patterns of ESBL- producing K. pneumoniae strains isolated from patients referred to Zanjan hospitals.


2012 ◽  
Vol 75 (3) ◽  
pp. 428-436 ◽  
Author(s):  
C. A. HALEY ◽  
D. A. DARGATZ ◽  
E. J. BUSH ◽  
M. M. ERDMAN ◽  
P. J. FEDORKA-CRAY

Concern about Salmonella contamination of food is compounded by fear that antimicrobials traditionally used to combat the infection will become useless due to rising antibiotic resistance. Livestock, in particular swine, often are blamed for illnesses caused by Salmonella and for increasing antibiotic resistance due to use of antibiotics in pigs. As part of the National Animal Health Monitoring System Swine 2000 and 2006 studies, swine fecal samples were cultured for Salmonella. These samples were collected from 123 operations in 17 states in 2000 and from 135 operations in 17 states in 2006. At each operation, 50 and 60 fecal samples were collected from late finisher pig pens in 2000 and 2006, respectively. Salmonella isolates were characterized to determine serogroup and serotype and were tested for susceptibility to a panel of 17 and 15 antimicrobial drugs in 2000 and 2006, respectively. A total of 5,470 and 7,788 samples were cultured for Salmonella in 2000 and 2006, respectively. Overall, 6.2% of the samples and 34.2% of the farms were positive for Salmonella in 2000. In 2006, 7.2% of the samples and 52.6% of the farms were positive. Salmonella Derby, Salmonella Typhimurium var. 5− (formerly Salmonella Typhimurium var. Copenhagen), and Salmonella Agona were the three serotypes most often recovered in both study years. The most common antimicrobial resistance pattern for Salmonella Derby in the two study years was resistance to streptomycin, sulfisoxazole, and tetracycline. Most isolates were resistant to tetracycline, sulfisoxazole, and streptomycin in both study years. The proportion of Salmonella isolates that were susceptible to all antimicrobials (pansusceptible) was 38.1% in 2000 and 20.4% in 2006. The proportion of Salmonella isolates that were resistant to three or more antimicrobials (multidrug resistant) was similar in 2000 and in 2006 (52.8 and 57.7%, respectively).


Antibiotics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 447
Author(s):  
Barbara Kot ◽  
Agata Grużewska ◽  
Piotr Szweda ◽  
Jolanta Wicha ◽  
Urszula Parulska

The aim of this study was to determine antibiotic resistance patterns and the prevalence of uropathogenes causing urinary tract infections (UTIs) in patients hospitalized in January–June 2020 in central Poland. Antimicrobial susceptibility testing was performed using the disk-diffusion method. Escherichia coli (52.2%), Klebsiella pneumoniae (13.7%), Enterococcus faecalis (9.3%), E. faecium (6.2%), and Proteus mirabilis (4,3%) were most commonly isolated from urine samples. E. coli was significantly more frequent in women (58.6%) (p = 0.0089) and in the age group 0–18, while K. pneumoniae was more frequent in men (24.4%) (p = 0.0119) and in individuals aged 40–60 and >60. Gram-negative species showed resistance to ampicillin. K. pneumoniae were resistant to amoxicillin plus clavulanic acid (75.0%), piperacillin plus tazobactam (76.2%), cefotaxime (76.2%), cefuroxime (81.0%), ciprofloxacin (81.0%), and trimethoprim plus sulphamethoxazole (81.0%). Carbapenems were effective against all E. coli and P. mirabilis. Some K. pneumoniae (13.6%) produced metallo-β-lactamases (MBLs). E. coli (22.6%), K. pneumoniae (81.8%), and all E. faecium were multidrug-resistant (MDR). Some E. coli (26.2%), K. pneumoniae (63.6%), and P. mirabilis (14.3%) isolates produced extended-spectrum beta-lactamases (ESBL). Vancomycin-resistant E. faecium was also found. This study showed that the possibilities of UTIs therapy using available antibiotics become limited due to the increasing number of antibiotic-resistant uropathogens.


2021 ◽  
Vol 8 ◽  
Author(s):  
Ilona Stefańska ◽  
Ewelina Kwiecień ◽  
Katarzyna Jóźwiak-Piasecka ◽  
Monika Garbowska ◽  
Marian Binek ◽  
...  

The spread of resistance to antibiotics is a major health concern worldwide due to the increasing rate of isolation of multidrug resistant pathogens hampering the treatment of infections. The food chain has been recognized as one of the key routes of antibiotic resistant bacteria transmission between animals and humans. Considering that lactic acid bacteria (LAB) could act as a reservoir of transferable antibiotic resistance genes, LAB strains intended to be used as feed additives should be monitored for their safety. Sixty-five LAB strains which might be potentially used as probiotic feed additives or silage inoculants, were assessed for susceptibility to eight clinically relevant antimicrobials by a minimum inhibitory concentration determination. Among antimicrobial resistant strains, a prevalence of selected genes associated with the acquired resistance was investigated. Nineteen LAB strains displayed phenotypic resistance to one antibiotic, and 15 strains were resistant to more than one of the tested antibiotics. The resistance to aminoglycosides and tetracyclines were the most prevalent and were found in 37 and 26% of the studied strains, respectively. Phenotypic resistance to other antimicrobials was found in single strains. Determinants related to resistance phenotypes were detected in 15 strains as follows, the aph(3″)-IIIa gene in 9 strains, the lnu(A) gene in three strains, the str(A)-str(B), erm(B), msr(C), and tet(M) genes in two strains and the tet(K) gene in one strain. The nucleotide sequences of the detected genes revealed homology to the sequences of the transmissible resistance genes found in lactic acid bacteria as well as pathogenic bacteria. Our study highlights that LAB may be a reservoir of antimicrobial resistance determinants, thus, the first and key step in considering the usefulness of LAB strains as feed additives should be an assessment of their antibiotic resistance. This safety criterion should always precede more complex studies, such as an assessment of adaptability of a strain or its beneficial effect on a host. These results would help in the selection of the best LAB strains for use as feed additives. Importantly, presented data can be useful for revising the current microbiological cut-off values within the genus Lactobacillus and Pediococcus.


PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0254836
Author(s):  
Yi Wang ◽  
Pramod K. Pandey ◽  
Sundaram Kuppu ◽  
Richard Pereira ◽  
Sharif Aly ◽  
...  

Antibiotic resistance genes (ARGs) are emerging contaminants causing serious global health concern. Interventions to address this concern include improving our understanding of methods for treating waste material of human and animal origin that are known to harbor ARGs. Anaerobic digestion is a commonly used process for treating dairy manure, and although effective in reducing ARGs, its mechanism of action is not clear. In this study, we used three ARGs to conducted a longitudinal bench scale anaerobic digestion experiment with various temperatures (28, 36, 44, and 52°C) in triplicate using fresh dairy manure for 30 days to evaluate the reduction of gene abundance. Three ARGs and two mobile genetic elements (MGEs) were studied: sulfonamide resistance gene (sulII), tetracycline resistance genes (tetW), macrolide-lincosamide-streptogramin B (MLSB) superfamily resistance genes (ermF), class 1 integrase gene (intI1), and transposase gene (tnpA). Genes were quantified by real-time quantitative PCR. Results show that the thermophilic anaerobic digestion (52°C) significantly reduced (p < 0.05) the absolute abundance of sulII (95%), intI1 (95%), tnpA (77%) and 16S rRNA gene (76%) after 30 days of digestion. A modified Collins–Selleck model was used to fit the decay curve, and results suggest that the gene reduction during the startup phase of anaerobic digestion (first 5 days) was faster than the later stage, and reductions in the first five days were more than 50% for most genes.


2021 ◽  
Author(s):  
Namrata Kumari ◽  
Mukesh Kumar ◽  
Amit Katiyar ◽  
Abhay Kumar ◽  
Pallavi Priya ◽  
...  

Abstract Carbapenemase-producing clinical isolates are becoming more common over the world, posing a severe public health danger, particularly in developing nations like India. Carbapenem-resistant Gram-negative bacterial (CR-GNB) infection has become a fast-expending global threat with limited antibiotic choice and significant mortality. The aim of this study was to highlight the carbapenem-resistance among clinical isolates of hospital admitted patients in Bihar, India. A cross-sectional study was conducted with 101 clinical isolates of E. coli, K. pneumoniae, A. baumannii, and P. aeruginosa. All GNB isolates were tested for their antimicrobial susceptibility using double disc synergy test / modified hodge test (DDST/MHT) and subsequently confirmed carbapenemase-producing isolates were evaluated for carbapenem-resistance genes using whole-genome sequencing (genotypically) method. The overall percentage of carbapenem-resistance among GNB was (17/101) 16.83%. The AMR analysis demonstrates a significantly high prevalence of blaCTX−M followed by blaSHV, blaTEM, blaOXA and blaNDM β-lactams carbapenem-resistance genes among clinical isolates of GNB. Co-occurrence of carbapenemase-encoding genes with blaNDM was found in 70.6% of carbapenemase-producing isolates. Our study highlights the mechanism of carbapenem-resistance to curb the overwhelming threat posed by emergence of drug-resistance in India.


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