3rd Generation of Cephalosporins and Monobactam Resistant Among Pathogenic Bacteria Collected from Ilam Hospitals During 2008 to 2015: A Systematic Review and Meta-Analysis.

BACKGROUND: Recently, increasing antibiotic resistance is causing serious publichealth concerns worldwide. This phenomenon increased patient's morbidity and mortality rate, particularly in immunocompromised individuals. METHODS: Considering that antimicrobial resistance can vary according to geographical location, we investigated the status of antibiotic resistance in Ilam province from 2008 to 2013. RESULTS: The results of our study showed that antibiotic resistance rates to aztreonam, cefotaxime, ceftazidime and ceftriaxone were 38%, 39%, 43% and 48% respectively. CONCLUSION: Antibiotic resistance had increased (except for aztreonam) during the period from 2008 to 2013.

Association between toxin-antitoxin systems and biofilm formation.

BACKGROUND: Toxin-antitoxin (TA) systems are found on the chromosomes and plasmids of many Bacteria such as Escherichia coli. The roles of TA systems in bacteria are enigmatic. Multiple biological functions of TA systems are proposed including growth modulation, persistence, and biofilm formation. Biofilms of E. coli are cause of urinary tract infections, as well as bacteraemia. OBJECTIVES: The current study aimed to find the association between biofilm formation and toxin-antitoxin systems in clinical isolates of E. coli. MATERIALS AND METHODS: A total of 150 E. coli isolates were evaluated for biofilm formation by Congo red agar medium (CRA) and microtiter plate assay and the presence of different TA systems including MazEF, RelBE, hipBA, ccdAB and MqsRA. RESULTS: The results of the analysis revealed that 107 E. coli isolates were potent for biofilm formation by CRA. The findings by microtiter plates showed that 102 E. coli isolates were biofilm producers. The results indicated that 80%, 85%, 70%, 91% and 82% of the isolates possessed MazEF, RelBE, hipBA, ccdAB and MqsRA TA loci, respectively. CONCLUSIONS: The analysis recommended that TA genes are prevalent in clinical isolates of E. coli strains. The analysis revealed that hipBA TA system is associated with biofilm formation.

The correlation between the presence of quorum sensing, toxin-antitoxin system genes and MIC values with ability of biofilm formation in clinical isolates of Pseudomonas aeruginosa.

INTRODUCTION: Pseudomonas aeruginosa is a Gram-negative bacterium that considered as important opportunistic human pathogen. One of the mechanisms that help bacteria to tolerate survival in adverse conditions and resistance to antibiotics is biofilm formation through quorum sensing (QS) signals and toxin-antitoxin (TA) systems. QS and TA are two systems that have important roles in biofilm formation. QS is a global regulatory mechanism that enable bacteria to communicate with each other by production of auto inducers (AI) molecules in population. Because of importance biofilm formation in P. aeruginosa infections, here, we studied frequency of QS and TA genes among clinical isolates of P. aeruginosa with ability of biofilm formation. MATERIALS AND METHODS: One hundred and forty clinical isolates of P. aeruginosa were collected from Tehran and Ilam hospitals. The isolates were identified by biochemical tests. Biofilm formation was evaluated by microplate method. After DNA extraction by boiling method, the frequency of QS genes (lasIR, rhlIR), and TA genes (mazEF, relBE, hipBA, ccdAB and mqsR) were analyzed by PCR. RESULTS: Our results showed that maximum resistance is related to aztreonam (72.85%) antibiotic. Most of isolates were able to produce biofilm (87.15%) and the majority of them formed strong biofilm (56.42%). PCR results showed that frequency of mazEF, relBE, hipBA, ccdAB, mqsR, lasIR and rhlIR genes were 85.71, 100, 1.42, 100, 57.14, 93.57 and 83.57 percent, respectively. CONCLUSION: Clinical isolates of P. aeruginosa had high ability to form biofilm, and QS and TA system genes among these isolates were very high (except hipBA genes). There are significaut correlation between biofilm for mation and present of QS and TA system genes.