جستجوی مقالات مرتبط با کلیدواژه « field gel electrophoresis » در نشریات گروه « پزشکی »

Production of extended-spectrum β-lactamase (ESBL) is one of the antibiotic resistance strategies in the bacteria. Extended spectrum β-lactamase producing Escherichia coli (E. coli) infections alarmingly increased in recent years in Turkey.
The current study aimed at determining antibiotic resistance and genotypic profiles of ESBL-positive E. coli isolates.
Forty-five ESBL-positive E. coli species were isolated from a variety of units both at the Mevlana University Foundation Hospital and the Mevlana University Medical Center at Konya province in Turkey from December 2013 to December 2014. Antibiotic resistance profile was determined by the Kirby-Bauer disk diffusion method. Genotypic profile was determined by pulsed-field gel electrophoresis (PFGE).
The rate of ESBL production in E. coli strains was 13.1%. The isolates were highly resistant to penicillins, cephalosporins, and monobactams, while very low resistant to carbapenems. Four PFGE profiles were identified: profile A (2%), profile B (2%), profile C (67%), and profile D (29%). Profile C, the most commonly identified profile, possessed 6 subprofiles (profiles C1 - C6) with more than 85% clonal similarity; Profile C2 was the commonest identified subprofile of profile C (27%).
Extended spectrum β-lactamase producing E. coli strains were highly resistant to β-lactam antibiotics.

Ralstonia mannitolilytica is an emerging opportunistic pathogen. Hospital outbreaks of Ralstonia spp. are mainly associated with contaminated treatment water or auxiliary instruments.
In this report, we summarize the clinical infection characteristics of R. mannitolilytica, the drug-susceptibility testing of the bacterial strains, and the results of related infection investigations.
Patients and We retrospectively analyzed the clinical information of 3 patients with R. mannitolilytica.
The patients’ primary-onset symptoms were chills and fever. The disease progressed rapidly and septic shock symptoms developed. Laboratory tests indicated progressively decreased white blood cells and platelets, as well as significant increases in certain inflammation indicators. The effect of treatment with Tazocin was good. The growth period of R. mannitolilytica in sterile distilled water was > 6 months. The pulsed-field gel electrophoresis (PFGE) results revealed that the infectious strains from these 3 patients were not the same clonal strain. This bacterium was not detected in the nosocomial infection samples.
Our results suggest that R. mannitolilytica-induced septicemia had an acute disease onset and rapid progression. The preferred empirical antibiotic was Tazocin. In these 3 cases, the R. mannitolilytica-induced septicemia was not due to clonal transmission.

Staphylococci are some of the most common causes of infections in birds. Worldwide, the dramatic increase in the prevalence of antimicrobial-resistant Staphylococcus aureus (S. aureus) is receiving widespread attention, due to multi-resistant strains, diminishing the usefulness of antibiotics in human medicine and, thereby limiting therapeutic options.. In this study, we characterized the distribution and antibiotic resistance patterns of methicillin resistant S. aureus (MRSA) strains, isolated from lying hen farms in Karaj, Iran. The pulsed field gel electrophoresis patterns and the staphylococcus cassette chromosome mec (SCCmec) types were also determined.. Over a period of 90 days (collected at days: 0, 45, 90) during 2013, nine samplings, consisting of swab samples and litter collection, were done from three poultry farms (three each) and a total of 55 MRSA isolates were isolated from chromogenic MRSA selective agar. The clonality of MRSA strains was determined using pulsed field gel electrophoresis (PFGE) and the diversity in the structure of SCCmec elements and also different ccr types was studied. Susceptibility to seventeen antibiotics was determined, using disc diffusion method, according to Clinical and Laboratory Standards Institute recommendation.. Out of the 55 MRSA strains, all isolates were at least resistant to penicillin, 58% showed resistance to erythromycin and 55% were resistant to ciprofloxacin. On the other hand, all isolates showed susceptibility to vancomycin, quinuprostin-dalfopristin, linezolid, fusidic acid, nitrofurantoin and minocycline. The results of PFGE showed diverse pulsotypes, consisting of 13 common types and 18 single types, with seven common PFGE types, which were found among the MRSA strains, isolated from different farms, suggestive of an epidemiological link. Moreover, 67% of MRSA isolates shared SCCmec type III and showed type 3 ccr, indicating the hospital origin of the strains.. The results of this study illustrated the persistence of resistant bacteria in the environment, and highlight the reservoir of resistance, associated with use of antibiotics, as feed additive in poultry production..

There are 4 different genera (i.e. Vibrio, Aliivibrio, Photobacterium, and Shewanella) in the new classification of bioluminescent bacteria. The mechanism of bioluminescence has yet to be fully elucidated. Therefore, the determination of physiological and genetic characteristics of bioluminescent bacteria isolated from different sources is very important. Pulsed-Field Gel Electrophoresis (PFGE) has the highest discriminatory power among the different molecular typing methods for the investigation of the clonal relationships between bacteria. For the PFGE analysis of bioluminescent bacteria, the NotI-HF™ is the method of choice among the restriction enzymes. The present study aimed to determine genetic relatedness via PFGE in 41 bioluminescent bacteria (belonging to 10 different species) isolated and identified from various marine sources. Different bioluminescent bacteria (i.e. Vibrio gigantis, V. azureus, V. harveyi, V. lentus, V. crassostreae, V. orientalis, Aliivibrio logei, A. fischeri, Shewanella woodyi, and Photobacterium kishitanii) were analyzed by PFGE using the NotI-HF™ restriction enzyme. The whole DNA of the strains embedded into the agarose plugs was digested with enzyme at 37°C for 30 minutes. CHEF-Mapper PFGE system was used for electrophoresis and band profile of the strains for the NotI-HF™ restriction enzyme were analyzed by Bio-Profil-1D++ software (Vilber Lourmat) at 10% homology coefficient. Although all experiments were performed three times, four of forty-one bioluminescent strains (V. gigantis E-16, H-16 and S3W46 strains and A. fischeri E-4 strain) could not be typed by PFGE technique with NotI-HF™ enzyme. While only two strains (V. crassostreae H-12 and H-19 strains) were exhibiting same band pattern profiles (100% genome homology), thirty-six different PFGE band patterns were obtained. Pattern homologies changed between 66% - 92%, 73% - 83% and 49% - 100% for V. gigantis, V. harveyi and other strains, respectively. The obtained results revealed that there has been a high rate of genetic diversity in bioluminescent strains isolated from Gulf of Izmir and V. lentus and V. crassostreae strains could be also bioluminescent for the first report. At the same time, PFGE analysis of bioluminescent bacteria including four different genera and ten different species were shown for the first time by this study. It is considered that data acquired by this study will contribute evolution and mechanism of bioluminescence to further works to be done.

Acinetobacter baumannii is an aerobic non-motile Gram-negative bacterial pathogen that is resistant to most antibiotics. Carbapenems are the most common antibiotics for the treatment of infections caused by this pathogen. Mechanisms of antibiotic-resistance in A. baumannii are mainly mediated by efflux pumps-lactamases. The aim of this study was to determine antibiotic susceptibility, the possibility of existence of OXAs genes and fingerprinting by Pulsed-Field Gel Electrophoresis (PFGE) among clinical isolates of Acinetobacter collected from Kermanshah hospitals. One hundred and four isolates were collected from patients attending Imam Reza, Taleghani and Imam Khomeini hospitals of Kermanshah (Iran). Isolates were identified by biochemical tests and API 20NE kit. The susceptibility to different antibiotics was assessed with Kirby-Bauer disk diffusion method. PCR was performed for detection of blaOXA-23, blaOXA-24, blaOXA-51 and blaOXA-58 beta-lactamase genes. Clonal relatedness was estimated by PFGE (with the restriction enzyme Apa I) and DNA patterns were analyzed by Gel compare II 6.5 software. All isolates showed high-level of resistance to imipenem, meropenem as well as to other antimicrobial agents, while no resistance to polymyxin B, colistin, tigecylcine and minocycline was observed. The blaOXA-23like and blaOXA-24 like were found among 77.9% and 19.2% of the isolates, respectively. All isolates were positive for blaOXA-51, but none produced any amplicon for blaOXA-58. PFGE genotype analysis suggested the existence of eight clones among the 104 strains [A (n = 35), B (n = 29), C (n = 19), D (n = 10), E (n = 4), F (n = 3), G (n = 3), H (n = 1)]. Clone A was the dominant clone in hospital settings particularly infection wards so that the isolates in this group, compared to the other clones, showed higher levels of resistance to antibiotics. The blaOXA-51-like and blaOXA-23like were the predominant mechanisms of resistance to imipenem in A. baumannii. A high prevalence of clone A, B and C in different parts of the healthcare system showed that hospitalized patients should be safeguarded to prevent the spread of these clones. Early recognition of the presence of carbapenem-resistant A. baumannii clones is useful for preventing their spread within the hospital environment.