Phenotypic and genotypic evaluation of fluoroquinolone resistance in clinical isolates of Staphylococcus aureus in Tehran

Background: Fluoroquinolones are broad-spectrum antibiotics widely used in the treatment of bacterial infections such as Staphylococcus aureus isolates. Resistance to these antibiotics is increasing. Material/Methods: The occurrence of mutations in the grlA and gyrA loci were evaluated in 69 fluoroquinolone-resistant S. aureus isolates from 2 teaching hospitals of Tehran University of Medical Sciences. Results: Out of the 165 S. aureus isolates, 87 (52.7) were resistant to methicillin and 69 (41.8) were resistant to fluoroquinolone. Fluoroquinolone-resistant S. atoms isolates had a mutation at codon 80 in the grlA gene and different mutational combinations in the gyrA gene. These mutational combinations included 45 isolates at codons 84 and 86,23 isolates at codons 84,86 and 106 and 1 isolate at codons 84, 86 and 90. Fluoroquinolone-resistant S. aureus isolates were clustered into 33 PFGE types. Conclusions: The findings of this study show that the fluoroquinolone-resistant S. aureus strains isolated in the teaching hospitals in Tehran had multiple mutations in the QRDRs region of both grlA and gyrA genes

VIRULENCE FACTORS, ANTIMICROBIAL SUSCEPTIBILITY AND MOLECULAR CHARACTERIZATION OF STREPTOCOCCUS AGALACTIAE ISOLATED FROM PREGNANT WOMEN

Forty-one Streptococcus agalactiae isolates collected from pregnant women at 35-37 weeks of gestation were analysed for their capsular types, antimicrobial resistance determinants, distribution of virulence factors and genetic relatedness using PCR and multiplex PCR. Capsular type III was predominant (65.8), followed by capsular type II (14.6), Ib (7.3), and V(4.9). All isolates were susceptible to penicillin, vancomycin, linezolid and quinupristin-dalfopristin. Resistance to tetracycline, erythromycin and clindamycin were found in 97.6, 24.4, and 14.6 of isolates, respectively. The most common antimicrobial resistance gene was tetM found in 97.6 of the isolates followed by ermTR and ermB found in 12 and 7.3 of isolates, respectively. The most common virulence gene was hly (100), followed by scpB (97.6), bca (97.6), rib (53.65) and bac (4.9). The insertion sequence IS1548 was found in 63.4 of isolates. By multi locus variable number of tandem repeat analysis (MLVA) typing, 30 different allelic profiles or MLVA types (MTs) were identified. The most frequent was the MT1 (5/41, 12.2) and followed by MT2 (4/41, 9.75). Our data revealed that population structure of these isolates is highly diverse and indicates different MLVA types

Improvement of semen parameters after antibiotic therapy in asymptomatic infertile men infected with Mycoplasma genitalium

Objectives: To elucidate the association between asymptomatic infections caused by Mycoplasma genitalium and male infertility, and evaluate the role of antibiotic therapy in treatment of this failure. Methods: A total of 165 infertile males having abnormal semen parameters (study group) and 165 healthy fertile men (control group) were included. Semen samples were taken from all participants and after analyzing for semen parameters, undergone real-time PCR, microbial culture, and reactive oxygen species (ROS), as well as total antioxidant capacity (TAC) assays. Infected individuals of study group were treated with antibiotic. One month after the treatment completion, second semen samples were taken and subjected to all the tests mentioned. The data were analyzed using SPSS statistical software, version 22.0. Results: The frequency of M. genitalium was significantly higher in the infertile men compared with the fertile ones (9.7 vs. 1.2; p = 0.001). Mean cycle threshold (Ct) value was lower in infected infertile than infected fertile men (p < 0.001). All semen parameters, except volume, pH, and viscosity, were improved (p < 0.05), most of which reached their normal range; leukocytes in seminal fluid decreased (p = 0.02), the level of TAC was elevated (p = 0.002), and ROS level as well as ROS/TAC ratio reduced after antibiotic treatment (p = 0.03). Wives of seven infected infertile men (43.8) became pregnant 4 months after the treatment completion. Conclusions: Asymptomatic infection caused by M. genitalium is correlated with male infertility and antibiotic therapy can improve the semen quality and be used to treat male infertility. © 2017, Springer-Verlag GmbH Germany

Comparison of ELISA and histopathologic and bacteriologic findings in diagnosis of helicobacter pylori in gastro-intestinal disorders

Helicobacter pylori (H.Pylori) is the most common human infection in the world. This agent has a strong role in pathogenesis of chronic gastritis and peptic ulcer. Therefore introducing of simple and cost effective tests are important for diagnosis of H.Pylori infections. ELISA has been considered as an alternative test compare with biopsy, histological staining, culture and urease test in diagnosis of H.Pylori infection. In this investigation, 111 patients referred to GI endoscopy department of Imam Khomeini Hospitals for U.G.I problems which were evaluated for H.Pylori infection. Culture and histological staining (GIMSA and H & E) were used as a gold standard test compare with ELISA-IgG and urease test. Sensitivity and specificity for ELISA were 90%, 93% respectively. This report suggests that ELISA is a cost effect and valid test in diagnosis of H.Pylori infectio

Multiple-locus variable number of tandem repeats (VNTR) fingerprinting (MLVF) and antibacterial resistance profiles of extended spectrum beta lactamase (ESBL) producing Pseudomonas aeruginosa among burnt patients in Tehran

Extended spectrum p-lactamase (ESBL)-producing trait was present in 48 out of the 112 (42.8) Pseudomonas aeruginosa isolates collected from burn wound infections during a 12-month period. The presence of oxa-10, per-1, veb-1 and ges genes and the multiple-locus variable number of tandem repeats (VNTR) fingerprinting (MLVF) of 112 P. aeruginosa strains were determined by PCR and multiplex PCR. Disk diffusion methods were used to determine the susceptibility of the isolates to antimicrobial agents as instructed by CLSI. All ESBL isolates were resistant to aztreonam, cefepime, cefotaxime, cefpodoxime, ceftazidime, ceftriaxone and ofloxacin. Fewer than 60 of ESBL isolates were resistant to imipenem, meropenem, and piperacillin-tazobactam but more than 90 were resistant to amikacin, ciprofloxacin, levofloxacin, ticarcillin and tobramycin. The most prevalent ESBL genes included oxa-10 (70) and per-1 (50) followed by veb-1 (31.3). The gene encodes GES enzyme did not detect in any isolates. A total of 100 P. aeruginosa strains were typed by MLVF typing method. MLVF produced 42 different DNA banding patterns. These data indicate that different MLVF types infect burn wounds in patients at a hospital in Tehran and also suggest an alarming rate of ESBL-producing isolates in this test location. (C) 2011 Elsevier Ltd and ISBI. All rights reserved

Improvement of semen parameters after antibiotic therapy in asymptomatic infertile men infected with Mycoplasma genitalium

Objectives: To elucidate the association between asymptomatic infections caused by Mycoplasma genitalium and male infertility, and evaluate the role of antibiotic therapy in treatment of this failure. Methods: A total of 165 infertile males having abnormal semen parameters (study group) and 165 healthy fertile men (control group) were included. Semen samples were taken from all participants and after analyzing for semen parameters, undergone real-time PCR, microbial culture, and reactive oxygen species (ROS), as well as total antioxidant capacity (TAC) assays. Infected individuals of study group were treated with antibiotic. One month after the treatment completion, second semen samples were taken and subjected to all the tests mentioned. The data were analyzed using SPSS statistical software, version 22.0. Results: The frequency of M. genitalium was significantly higher in the infertile men compared with the fertile ones (9.7 vs. 1.2; p = 0.001). Mean cycle threshold (Ct) value was lower in infected infertile than infected fertile men (p < 0.001). All semen parameters, except volume, pH, and viscosity, were improved (p < 0.05), most of which reached their normal range; leukocytes in seminal fluid decreased (p = 0.02), the level of TAC was elevated (p = 0.002), and ROS level as well as ROS/TAC ratio reduced after antibiotic treatment (p = 0.03). Wives of seven infected infertile men (43.8) became pregnant 4 months after the treatment completion. Conclusions: Asymptomatic infection caused by M. genitalium is correlated with male infertility and antibiotic therapy can improve the semen quality and be used to treat male infertility. © 2017, Springer-Verlag GmbH Germany

ISPpu22, a novel insertion sequence in the oprD porin gene of a carbapenem-resistant Pseudomonas aeruginosa isolate from a burn patient in Tehran, Iran

BACKGROUND AND OBJECTIVES: The oprD mutation and AmpC overproduction are the main mechanisms of intrinsic resistance to carbapenems such as imipenem and meropenem in Pseudomonas aeruginosa. MATERIALS AND METHODS: In this study, we investigated intrinsic resistance to carbapenems including mutation of oprD and AmpC overproduction in a carbapenem-resistant P. aeruginosa isolated from a burn patient by phenotypic and molecular methods. RESULTS: In our study, the carbapenem-resistant P. aeruginosa isolate was resistant to imipenem, meropenem, cefepime, gentamicin, ceftriaxone, carbenicillin, aztreonam and ciprofloxacin but was susceptible to ceftazidime and polymyxin B. The minimum inhibitory concentrations (MICs) against imipenem, meropenem and ceftazidime were 64 μg/ml, 16 μg/ml and 2μg/ml, respectively. The isolate was ESBLs and AmpC overproducer. No carbapenemase activity was detected by Modified Hodge test (MHT). This isolate was carrying only bla OXA-10 . PCR amplification and sequencing of oprD performed on isolate resulted in PCR product of 2647bp. Sequence analysis of the 2647bp product revealed insertion of a sequence of 1232 bp at position 8 in coding region of oprD. CONCLUSION: According to the results of this study, oprD mutation and AmpC overproduction can cause the main mechanism of resistance of P. aeruginosa to carbapenems

Genetic similarity between adenoid tissue and middle ear fluid isolates of Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis from Iranian children with otitis media with effusion

Background: Otitis media with effusion (OME) is a common disease among children, in the pathogenesis of which bacterial infections play a critical role. It was suggested that adenoid tissue could serve as a reservoir for bacterial infection, the eustachian tubes being the migration routes of bacteria into the middle ear cavity. The aim of this study was to investigate the genetic similarity between isolates of Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis, obtained from adenoid tissue and middle ear fluid. Methods: A total of 60 specimens of middle ear fluids (MEFs) and 45 specimens of adenoid tissue were obtained from 45 children with OME. All the samples were inoculated on culture media for bacterial isolation and identification. The genetic similarity between bacterial isolates was determined by pulsed-field gel electrophoresis (PFGE). Results: The same bacterial species were simultaneously isolated from adenoid tissue and MEFs of 14 patients, among which, 6 pairs of M. catarrhalis, 5 pairs of S. pneumoniae and 3 pairs of H. influenzae were identified. Conclusions: Based on the genetic similarities between isolate pairs, found by PFGE analysis, this study suggested that M. catarrhalis, S. pneumoniae and H. influenzae colonize the adenoid tissue, then migrate to the middle ear cavity and, hence, contribute to the total pathogenesis of OME. (C) 2013 Elsevier Ireland Ltd. All rights reserved