Under high concentrations of antibiotics, a fraction of the bacterial population exhibits a phenomenon known as persistence. Toxin- system (TA system) has been reported to be involved in the formation of E. coli, Mycobacterium, and S. aureus persisters. In this study, the ability of thirty Iraqi isolates of MRSA to form in vitro persister cells after exposure to three different antibiotics (Ceftriaxone 30 µg, Mecillinam 10 µg, and Mupirocin 20 µg) was examined by TD test. Additionally, efflux pump inhibitor [Fluphenazine 0.25 mg/ml] was combined with the antibiotic that triggered persister formation. The distribution of mazEF and yefM-yoeB (Type II TA system) in the tested isolates was detected by PCR. 91% of Mupirocin susceptible isolates formed persister cells.42% of the persistent level was reduced when Mupirocin was combined with the Fluphenazine. Genes for homologs of the yefM-yoeB and mazEF TA system were present in 100% of the tested isolates. The prevalence of these genes in the tested isolates suggested a link between persistence and the TA system. Further investigation is required to study the expression of these genes under stress conditions.
Atotal of 75 different clinical samples were collected from different hospitals in Baghdad Biochemical and morphological characterization tests showed that forty isolates were identified as Staphylococcus aureus Antibiotic susceptibility tests of all isolates towards ten antibiotics were carried out and results showed that many isolates (97.5 %) were resistant to ?-lactam antibiotic , 70 % were resistant to Tetracyclinee , 62.5% were resistant to co-trimoxazole , 60 % were resistant to ciprofloxacin , 55% were resistant both of chloramphenicol and erythromycin , 52.5% were resistant to gentamicin , 35% were resistant to rifampicin , 10% were resistant to vancomycin . According to the above results the S.aureus I1 which is isolated
... Show MoreObjective: The present work was undertaken to investigate the impact of sub inhibitory concentration of gentamicin on hla gene expression in methicillin resistant Staphylococcus aureus isolates. Methods: The bacterial isolates used in this study represent 33 MRSA strains, previously isolated form patients visiting several hospitals in Baghdad. Gentamicin, vancomycin, and oxacillin MIC were determined using broth dilution method. Microtiter plate method was adopted to investigate the biofilm forming capacity. Alpha hemolysin was detected by culturing MRSA isolates on rabbit blood agar. Furthermore, hla gene was detected in MRSA isolates using conventional PCR technique; while, qRT-PCR method was performed to assay the hla expression in plank
... Show MoreIn accordance with epidemic COVID-19, the elevated infection rates, disinfectant overuse and antibiotic misuse what led to immune suppression in most of the population in addition to genotypic and phenotypic alterations in the microorganisms, so a great need to reevaluate the genetic determinants that responsible for bacterial community (biofilm) has been raised. A total of 250 clinical specimens were obtained from patients in Baghdad hospitals and streaked on Mannitol salt agar medium. The results revealed that 156 isolates appeared as round yellow colonies, indicating that they were mostly identified as Staphylococcus aureus from 250 specimens. The antibiotic resistance pattern of the isolates for methicillin 37.17% (n=58), Amoxic
... Show MoreThe photodynamic inactivation against Methicillin-resistant Staphylococcus aureus using two different lasers, 532 nm diode pumped solid state laser (DPSS) in combination with safranin O and 650 nm diode laser in combination with methylene blue was investigated in the present work. A hundred swab samples were collected from patients with burn and wound infections admitted to two hospitals in Baghdad (Specialized Burns Hospital in Medical City and Al Imamein Al Jwadein Medical City Hospital) from December 2015 to February 2016 Antimicrobial susceptibility was performed by using Kirby- Bauer method. The irradiation experiments included four groups; a control group, a photosensitizer only group, a laser irradiation only group and a laser irr
... Show MoreBackground: Globally, breast cancer is the second leading cause of death among women in Iraq. Several genetic and environmental factors are associated..
The isolates of Staphylococcus aureus were isolated from patients with various infections in hospitals, the isolates were identified and accurately diagnosed by phenotypic examination and biochemical tests, as well Vitek-2, and then genetic detection and diagnosis of many of the pathogenic factors associated with Staphylococcus aureus using conventional polymerase chain reaction (PCR) and testing for association by antibiotic resistance and production of some toxins by Staphylococcus aureus. After performing analysis of statistical, it was set up that the correlation coefficient of the PCR technique using virulence genes, sensitivity test to antibiotics and other virulence factors were significant at p < 0.05, but was insignificant with the
... Show MoreTo elucidate the anti- Methicillin resistance Staphylococcus aureus (MRSA) effect of pomegranate alone and in combination with moxifloxacin fluoroquinolone. A total of five clinical isolates of MRSA (ATCC 43300) were used in the study. Disc diffusion method was used to determine the anti-MRSA effect of pomegranate and/or moxifloxacin by using Mueller-Hinton agar. Minimal inhibitory concentration (MIC), fractional inhibitory concentration (FIC) of moxifloxacin and pomegranate were calculated, the dynamic picture of the bactericidal effect of pomegranate and/or moxifloxacin was determined. SPSS version 20.00 was used for data analysis. Zone of inhibition (ZOI) of moxifloxacin was 19.67±4.84mm which was not significant compared with pomegrana
... Show MoreStaphylococcus aureus, which includes the methicillin-resistant S. aureus (MRSA), is a significant human pathogen producing different toxins and results in many different infection types, which include bacteremia, soft-tissue infections, as well as staphylococcal food poisoning. S. aureus is an important food-borne pathogen of humans due to ingestion of food containing enterotoxigenic strains. Detecting S. aureus femA and mecA genes was evaluated with the use of a Loop-mediated Isothermal Amplification Method (LAMP). The accuracy of this approach was similar to that attained using the approach of the conventional polymerase chain (PCR). Those two methods characterized 43 isolates of MRSA which
... Show MoreThe pathogenicity resulting from Staphylococcus aureus infection has remarkable importance as one of the community-associated bacterial infections, due to the virulent ability of these bacteria to produce biofilms. This study was designed to detect biofilm production in clinical isolates from samples of wounds and urinary tract infections. The expression levels of the icaA gene that is responsible of slime layer production in biofilms was compared in isolates with different biofilm producing capabilities. Fifty seven samples that included 32 samples from urine and 25 samples from wounds were collected from Alwasti Hospital, Al-Kindi Teaching Hospital, and Alzahraa Clinic, Baghdad, Iraq. The bacteria was identified accor
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