Swarming is one of the most important virulence factors used by bacteria to invade new sites. This study aimed to test the effects of gentamicin on swarming motility of Pseudomonas aeruginosa, both phenotypically and molecularly. The present results revealed that 11/25 isolates had gentamicin MIC of 1024 µg/ml. However, gentamicin at sub-minimal inhibitory concentration significantly (P< 0.05) reduced the diameter of swarming in all P. aeruginosa isolates. Noticeably the mean and median swarming diameter before treatment with gentamicin 5.557 and 5.816 cm respectively had significantly (P < 0.001) reduced to 0.871 and 0.766 cm respectively. At the molecular level, amrZ (a global regulator of multiple genes) and rhl (responsible for rhamnolipid production) were variably affected by gentamicin. More likely it can be concluded that amrZ and rhl are not fully responsible for swarming in P. aeruginosa isolates.
Objective: 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 MorePseudomonas aeruginosa is an opportunistic pathogen that causes a number of infections in immunocompromised patients. This organism appears to improve resistance to many antimicrobial agents and a high percentage of clinical isolates of P. aeruginosa exhibit multidrug resistance (MDR) phenotype . The purpose of this study is to screen the antibiotic susceptibility patterns and the prevalence of qacE delta1 gene among bacterial isolates. Accordingly, 145 samples were collected from different clinical sources from patients who admitted to different hospitals in Baghdad city in a period ranged 23/8/2018-1/1/2019. The isolates were diagnosed as P. aeruginosa based on routine b
... Show MoreObjectives: The current work aimed to reveal the impact of gentamicin on the fibronectin binding proteins (fnbp) gene expression and its relation to biofilm and agr type in Staphylococcus aureus. Materials and Methods: A total of 25 S. aureus isolates were enrolled in this study previously isolated from different specimens. Identification confirmation and methicillin resistance were achieved by amplification of 16SrRNA and mecA. Multiplex polymerase chain reaction (PCR) based assay was employed to evaluate the agr typing. The gene expression of fnbA and fnbB genes was tested by real-time PCR technique. Minimum inhibitory concentration was estimated by micro broth dilution methodology. Microtiter plate method was performed to determine the a
... Show MoreP. aeruginosa is a famous bacterium that causes several diseases and has a high ability to be a multidrug resistant organism that is linked with the formation of biofilm. This study aimed to investigate tssC1 gene role in the resistance of different antibiotics in the presence of biofilm. We constructed biofilm for the isolates under the study and showed the effect of different antibiotics on biofilm formation and maturation. The presence of the gene was detected through achieving PCR reaction. Finally, tssC1 gene variation was determined through sequencing and aligning the sequencing products. The results showed that most of the isolates (80%) formed biofilm that played a role in the resistance of different antibiotics which could be du
... Show MoreAccording to the prevalence of multidrug resistance bacteria, especially Pseudomonas aeruginosa, in which the essential mechanism of drug resistance is the ability to possess an efflux pump by which extrusion of antimicrobial agents usually occurs, this study aims to detect the presence of mexB multidrug efflux gene in some local isolates of this bacteria that show resistance towards three antibiotics, out of five. Sensitivity test to antibiotics was performed on all isolates by using meropenem (10µg/disc), imipenem (10µg/disc), amikacin (30 μg/disc), ciprofloxacin (5µg/disc) and ceftazidime (30 µg/disc). Conventional PCR results showed the presence of mexB gene (244bp) in four isolates out of t
... Show MoreOut of 120 isolates from different clinical cases, only 75 were found and confirmed that they belong to the Pseudomonas aeruginosa bacteria. The result revealed that the LasB virulent gene was present in 63 isolates with 63% percentage. The gel electrophoresis showed that the molecular weight of LasB gene was 300 bp. DNA sequences of LasB gene was done, and the results showed the presence of some gene mutations like substitution, addition and deletion with 97% identity with the Refseq gene. From the other side, the results of identities of translated nucleotides sequence with the original sequence of amino acids revealed that there are no effects of gene mutations on translation of the product protein.
PvcABCD are cluster of genes found in Pseudomonas aeruginosa. The research was designed to examine the relationship between the pvc genes expression and cupB gene, which plays a crucial role in the development of biofilm, and rhlR, which regulates the expression of biofilm-related genes, and to investigate whether the pvc genes form one or two operons. The aims were achieved by employing qRT-PCR technique to measure the gene expression of genes of interest. It was found that out of 25 clinical isolates, 21 isolates were qualified as P.aeruginosa. Amongst, 18(85.7%) were evaluated as biofilm producers, 10 (47.6%), 5 (23.8%), and 3 (14.2%) were evaluated as strong, moderate and weak producers respectively, while, 3 (14.2%) were considered
... Show MoreOne of the most causative agents for many opportunistic diseases is the Pseudomonas aeruginosa which has a high percentage of multidrug resistance disease through construction of biofilm. The current study aimed for evaluating the correlation between quorum sensing genes (which is lasI gene) and biofilm formation. The biofilm construction and antibiotics susceptibility test were achieved for all the isolates under the study. The PCR and sequencing techniques were also carried out to detect the type of variation in lasI gene for each scheme of biofilm formation (weak, strong, and moderate). High antibiotic resistance was recorded among biofilm producing isolates. The genic pattern for the weak biof
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