scholarly journals Evaluation of Antimicrobial Susceptibility Pattern Changes and Antibiotic Resistance Genes of Vibrio cholerae O1 Strains Isolated in 2012-2015 Outbreaks in Iran Referred to Reference Laboratory Using Phenotypic and Molecular Methods

2019 ◽  
Vol 19 (2) ◽  
pp. 172-190
Author(s):  
Roghieh Saboorian ◽  
Mohammad Rahbar ◽  
Marjan Rahnamaye Farzami ◽  
Parvaneh Saffarian ◽  
◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Vibrio Cholerae ◽  
Resistance Genes ◽  
Antimicrobial Susceptibility ◽  
Antibiotic Resistance Genes ◽  
Molecular Methods ◽  
Reference Laboratory ◽  
Susceptibility Pattern ◽  
Antimicrobial Susceptibility Pattern ◽  
Vibrio Cholerae O1

scholarly journals Invasive isolates of Streptococcus pneumoniae in Serbia: Antimicrobial susceptibility and serotypes

2013 ◽  
Vol 141 (1-2) ◽  
pp. 48-53 ◽  
Author(s):  
Ina Gajic ◽  
Vera Mijac ◽  
Lazar Ranin ◽  
Dragana Andjelkovic ◽  
Miroslava Radicevic ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Invasive Pneumococcal Disease ◽  
Antimicrobial Susceptibility ◽  
Pneumococcal Disease ◽  
Medical Problem ◽  
Resistance Rate ◽  
Reference Laboratory ◽  
Susceptibility Pattern ◽  
Antimicrobial Susceptibility Pattern ◽  
Resistance Rates

Introduction. Streptococcus pneumoniae is one of the leading causes of bacterial meningitis and sepsis. Invasive pneumococcal disease is a significant medical problem worldwide, particularly in children, due to a huge increase of pneumococcal resistance to antibiotics. Objective. The aim of the study was to investigate the antimicrobial susceptibility pattern of invasive pneumococcal isolates, as well as to determine whether decreased S. pneumoniae susceptibility to antibiotics was related to a particular serotype. Methods. Antimicrobial susceptibility to 19 antibiotics was determined in 58 invasive pneumococcal strains that were collected from seven regional centers during the period July 2009 to February 2011 in the National Reference Laboratory for streptococci and pneumococci. Results. The overall nonsusceptibility rate to penicillin was detected in 34% of pneumococcal isolates and to erythromycin in 36%. Higher resistance rates were observed among children than among adults. Penicillin resistance rate was 65% in children versus 22% in adults, while erythromycin nonsusceptibility rate was 47% in children versus 32% in adults. Co-resistance to penicillin and erythromycin was detected in 21% strains, mostly isolated from children. Multiresistance was found in one third of isolates. All strains were susceptible to vancomycin, linezolid, fluoroquinolones, telithromycin and rifampicin, while 23 (40%) isolates were susceptible to all tested antibiotics. The most common resistant serotypes were 19F and 14. Conclusion. The study has revealed that penicillin and macrolide resistance among invasive pneumococcal isolates is very high in Serbia. This emphasizes the need for continuous monitoring for invasive pneumococcal disease to document the serotype distribution and antimicrobial susceptibility pattern.

scholarly journals Genomic and Functional Analyses of SXT, an Integrating Antibiotic Resistance Gene Transfer Element Derived from Vibrio cholerae

2002 ◽  
Vol 184 (15) ◽  
pp. 4259-4269 ◽  
Author(s):  
John W. Beaber ◽  
Bianca Hochhut ◽  
Matthew K. Waldor
Keyword(s):  
Antibiotic Resistance ◽  
Vibrio Cholerae ◽  
Resistance Genes ◽  
Antibiotic Resistance Gene ◽  
Antibiotic Resistance Genes ◽  
Amino Acid Sequences ◽  
Conjugation System ◽  
Conjugative Transposons ◽  
The One ◽  
Functional Analyses

ABSTRACT SXT is representative of a family of conjugative-transposon-like mobile genetic elements that encode multiple antibiotic resistance genes. In recent years, SXT-related conjugative, self-transmissible integrating elements have become widespread in Asian Vibrio cholerae. We have determined the 100-kb DNA sequence of SXT. This element appears to be a chimera composed of transposon-associated antibiotic resistance genes linked to a variety of plasmid- and phage-related genes, as well as to many genes from unknown sources. We constructed a nearly comprehensive set of deletions through the use of the one-step chromosomal gene inactivation technique to identify SXT genes involved in conjugative transfer and chromosomal excision. SXT, unlike other conjugative transposons, utilizes a conjugation system related to that encoded by the F plasmid. More than half of the SXT genome, including the composite transposon-like structure that contains its antibiotic resistance genes, was not required for its mobility. Two SXT loci, designated setC and setD, whose predicted amino acid sequences were similar to those of the flagellar regulators FlhC and FlhD, were found to encode regulators that activate the transcription of genes required for SXT excision and transfer. Another locus, designated setR, whose gene product bears similarity to lambdoid phage CI repressors, also appears to regulate SXT gene expression.

scholarly journals Identification of Operators and Promoters That Control SXT Conjugative Transfer

2004 ◽  
Vol 186 (17) ◽  
pp. 5945-5949 ◽  
Author(s):  
John W. Beaber ◽  
Matthew K. Waldor
Keyword(s):  
Antibiotic Resistance ◽  
Vibrio Cholerae ◽  
Resistance Genes ◽  
Antibiotic Resistance Genes ◽  
Conjugative Transfer ◽  
Multiple Antibiotic Resistance ◽  
Divergent Promoters

ABSTRACT Transfer of SXT, a Vibrio cholerae-derived integrating conjugative element that encodes multiple antibiotic resistance genes, is repressed by SetR, a λ434 cI-related repressor. Here we identify divergent promoters between s086 and setR that drive expression of the regulators of SXT transfer. One transcript encodes the activators of transfer, setC and setD. The second transcript codes for SetR and, like the cI transcript of lambda, is leaderless. SetR binds to four operators located between setR and s086; the locations and relative affinities of these sites suggest a model for regulation of SXT transfer.

scholarly journals Molecular Analysis of Antibiotic Resistance Gene Clusters in Vibrio cholerae O139 and O1 SXT Constins

2001 ◽  
Vol 45 (11) ◽  
pp. 2991-3000 ◽  
Author(s):  
Bianca Hochhut ◽  
Yasmin Lotfi ◽  
Didier Mazel ◽  
Shah M. Faruque ◽  
Roger Woodgate ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Vibrio Cholerae ◽  
Resistance Gene ◽  
Resistance Genes ◽  
Dna Sequences ◽  
Antibiotic Resistance Gene ◽  
Antibiotic Resistance Genes ◽  
Gene Clusters ◽  
Vibrio Cholerae O139 ◽  
El Tor

ABSTRACT Many recent Asian clinical Vibrio cholerae E1 Tor O1 and O139 isolates are resistant to the antibiotics sulfamethoxazole (Su), trimethoprim (Tm), chloramphenicol (Cm), and streptomycin (Sm). The corresponding resistance genes are located on large conjugative elements (SXT constins) that are integrated into prfC on the V. cholerae chromosome. We determined the DNA sequences of the antibiotic resistance genes in the SXT constin in MO10, an O139 isolate. In SXTMO10, these genes are clustered within a composite transposon-like structure found near the element's 5′ end. The genes conferring resistance to Cm (floR), Su (sulII), and Sm (strA and strB) correspond to previously described genes, whereas the gene conferring resistance to Tm, designated dfr18, is novel. In some other O139 isolates the antibiotic resistance gene cluster was found to be deleted from the SXT-related constin. The El Tor O1 SXT constin, SXTET, does not contain the same resistance genes as SXTMO10. In this constin, the Tm resistance determinant was located nearly 70 kbp away from the other resistance genes and found in a novel type of integron that constitutes a fourth class of resistance integrons. These studies indicate that there is considerable flux in the antibiotic resistance genes found in the SXT family of constins and point to a model for the evolution of these related mobile elements.

scholarly journals Investigation of Some Antibiotic Resistance Genes of Indigenous Lactobacilli Isolated From Traditional Yogurt In Zanjan Province of Iran

2021 ◽  
Author(s):  
Bahare Moghimi ◽  
Maryam Ghobadi Dana ◽  
Reza Shapouri
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Food Chain ◽  
Starter Culture ◽  
Antibiotic Resistance Genes ◽  
Molecular Methods ◽  
Diffusion Method ◽  
Resistant Bacteria ◽  
Fermented Foods ◽  
Antibiotic Resistant

Abstract Purpose: Given the increasing use of antibiotics on humans and livestock for treatment or as a growth stimulant, antibiotic resistance has become a general concern. The food chain and specially fermented foods could be a source of antibiotic-resistant bacteria and resistance genes. Lactic Acid Bacteria (LAB) and Lactobacilli are considered safe to use as starter culture or probiotic strains. Recently, however, antibiotic-resistant genes isolated from LABs showed the necessity of setting international regulations to reduce the risk of antibiotic resistance genes transmission via the food chain. The current study aimed to investigate the antibiotic resistance of Lactobacilli isolated from traditional yogurt samples from Zanjan province in Iran.Methods: Lactobacilli characterization and identification were carried out through biochemical and molecular methods. The disk diffusion method was applied to determine phenotype resistance using 13 antibiotic disks resistance genes presence were investigated in the isolates to determine transferability risk, respectively.Results: Based on biochemical and molecular methods, 24 isolates have been identified as Lactobacilli with multiple antibiotic-resistant phenotypes. Vancomycin resistance was a typical phenotype and genotype among isolates. On investigated Lactobacilli chromosome, Tetracycline resistance genes Chloramphenicol (cat), beta-lactam, aminoglycosides (aph (3’)-III), and aadA resistance genes have been detected. While the examined resistance genes have not been detected on the plasmids, they were all on the bacterial chromosome.Conclusion: The results showed that the investigated isolates did not carry the resistance genes on their plasmids. It, therefore, would be a good point since they probably do not transfer resistance genes to other bacteria, and they would be proper candidates to do more investigation for introducing new safe starter culture or probiotic strain to food industries.

scholarly journals Antimicrobial Resistance Genes in Porcine Pasteurella multocida Are Not Associated with Its Antimicrobial Susceptibility Pattern

Antibiotics ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 614
Author(s):  
Máximo Petrocchi-Rilo ◽  
César-B. Gutiérrez-Martín ◽  
Esther Pérez-Fernández ◽  
Anna Vilaró ◽  
Lorenzo Fraile ◽  
...  
Keyword(s):  
Resistance Genes ◽  
Antimicrobial Susceptibility ◽  
Pasteurella Multocida ◽  
Antimicrobial Agents ◽  
Tetracycline Resistance ◽  
Susceptibility Pattern ◽  
Antimicrobial Susceptibility Pattern ◽  
Tetracycline Resistance Genes ◽  
Antimicrobial Resistance Genes ◽  
Western Spain

Forty-eight Pasteurella multocida isolates were recovered from porcine pneumonic lungs collected from farms in “Castilla y León” (north-western Spain) in 2017–2019. These isolates were characterized for their minimal inhibition concentrations to twelve antimicrobial agents and for the appearance of eight resistance genes: tetA, tetB, blaROB1, blaTEM, ermA, ermC, mphE and msrE. Relevant resistance percentages were shown against tetracyclines (52.1% for doxycycline, 68.7% for oxytetracycline), sulphamethoxazole/trimethoprim (43.7%) and tiamulin (25.0%), thus suggesting that P. multocida isolates were mostly susceptible to amoxicillin, ceftiofur, enrofloxacin, florfenicol, marbofloxacin and macrolides. Overall, 29.2% of isolates were resistant to more than two antimicrobials. The tetracycline resistance genes (tetA and tetB) were detected in 22.9% of the isolates, but none were positive to both simultaneously; blaROB1 and blaTEM genes were found in one third of isolates but both genes were detected simultaneously in only one isolate. The ermC gene was observed in 41.7% of isolates, a percentage that decreased to 22.9% for msrE; finally, ermA was harbored by 16.7% and mphE was not found in any of them. Six clusters were established based on hierarchical clustering analysis on antimicrobial susceptibility for the twelve antimicrobials. Generally, it was unable to foresee the antimicrobial susceptibility pattern for each family and the association of each particular isolate inside the clusters established from the presence or absence of the resistance genes analyzed.

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