Molecular Study of PER and VEB Genes is Multidrug Resistant Pseudomonas aeroginosa Isolated From Clinical Specimens in Isfahan/Iran and their Antibiotic Resistance Patterns

Abstract: Background & Aims: Duo to clinical use of antibiotics, pseudomonas aeruginosa strains with multiple drugs resistance have significantly increased throughout the world. Betalactamase production is one of the Mechanisms involved in resistance to pseudomonas aeruginosa resulting in many problems in the treatment of infections caused by this bacterium. The aim of this study was molecular analysis of PER and VEB genes in Pseudomonas with multiple resistance isolated from clinical samples in Isfahan/Iran. Methods: In whole, 98 isolates of Pseudomonas aeruginosa from various clinical specimens were identified by biochemical tests and the antibiotic susceptibility of the identified strains were determined using Kirby-Bauer method. PCR was performed on the samples to evaluate the presence or absence of PER and VEB genes. Results: Among 98 strains of Pseudomonas aeruginosa, 73 samples (73%) were multiple drugs resistant and all of them were cefotaxime, cefepime and ceftazidime resistant. Prevalence of PER and VEB genes were respectively 5 (6.84%) and 8 (10.9%). Conclusion: Considering high prevalence of multi-drug resistant Pseudomonas aeroginosa, it is essential to reduce these pathogens in hospitals through controlling PER and VEB genes transfer. Keywords: Beta-lactamase, Pseudomonas aeruginosa, PER, VE

Role of Tsukamurella species in human infections: first literature review

Tsukamurella is an aerobic, Gram-positive and nonmotile bacterium. It was first isolated in 1941 from the mycetoma and ovaries of the bedbug. The primary strains were named Corynebacterium paurometabolum and Gordona aurantiaca and are different from the Collins et al., 1988 classification of the new Tsukamurella genus. Human infections with Tsukamurella species are rare because the species is a kind of saprophyte bacterium; however, most information regarding this species comes from case reports. Molecular markers for the identification Tsukamurella include sequencing of 16S rRNA, groEL, rpoB, secA1 and ssrA genes. Given the lack of information on the treatment of Tsukamurella infections, a combination of various antibiotic agents is recommended. Keywords: Isolation, molecular identification, taxonomy, Tsukamurell

Antimicrobial Resistance Pattern of Escherichia coli Isolated from Chickens with Colibacillosis in Yazd, Iran

Background: The antibiotic resistance is considered as one of the biggest public health concerns in most countries. The aim of this study was to determine antibiotic resistance pattern of Escherichia coli isolated from chickens with colibacillosis in Yazd, Iran. Methods: A total of 200 carcasses of Ross chickens with colibacillosis were collected from farms located around Yazd, central Iran. After autopsy, specimens were collected from air bags of carcasses using sterile swaps and transferred immediately to the laboratory. After microbiological culture, the isolates were confirmed by the conventional Polymerase Chain Reaction (PCR) assay. Antimicrobial susceptibility of E. coli isolates were determined by disk diffusion method. Results: Out of 200 specimens, 100 (50%) E. coli isolates were identified and confirmed by PCR method. The results of antimicrobial susceptibility tests showed the highest resistance against nalidixic acid (100%), enrofloxacin (87%), ciprofloxacin (86%), and erythromycin (82%), respectively. Also, the highest susceptibility was seen for colistin (100%), meropenem (94%), and gentamicin (93%), respectively. Conclusion: In this study, multidrug resistance was observed in avian pathogenic E. coli isolates that represents the heavy usage of these drugs in poultry flocks in Yazd, central Iran. Improper or overuse of antibiotics usage for treatment of the poultry diseases could play an important role in spreading of the antimicrobial resistance genes among pathogenic bacteria from human and animals especially through food chain

Genetic diversity and antimicrobial susceptibility of Nocardia species among patients with nocardiosis

The aim of this multicenter study was to determine the genetic diversity and antibiotic susceptibility of clinically isolated Nocardia species. One hundred twenty-seven patients with nocardiosis were randomly selected from 5 provinces of Iran. Molecular diagnosis of Nocardia species was performed using multilocus sequence analysis of gyrase B of the β subunit of DNA topoisomerase (gyrB), and 16S rRNA and subunit A of SecA preproteintranslocase (secA1). Antimicrobial susceptibility testing was performed following the Clinical and Laboratory Standards Institute recommendations. Thirty-five N. cyriacigeorgica, 30 N. asteroides, 26 N. farcinica, 12 N. otitidiscaviarum, and 10 N. abscessus cultures were studied. All isolates were susceptible to linezolid. All isolates of N. cyriacigeorgica, N. asteroides, N. abscessus, and N. otitidiscaviarum were susceptible to trimethoprim-sulfamethoxazole, while 8% of N. farcinica isolates were resistant to this drug. All N. otitidiscaviarum isolates were highly resistant to imipenem, but N. cyriacigeorgica, N. asteroides, N. farcinica, and N. abscessus were only moderate resistant. The susceptibility patterns vary with different species of Nocardia. Resistance to trimethoprim-sulfamethoxazole in Iran is low and this drug should be first line therapy, unless drug susceptibility testing shows resistance. Linezolid also covers Nocardia well and could be a second line agent