Silver nanoparticles have been considered a powerful antimicrobial agents recently especially after increasing incidence of diseases associated with biofilm and multi-drug resistant pathogens required to find a novel path to eradicate that challenge. The present study aims to evaluate the antibacterial activity of biosynthesized silver nanoparticles (AgNPs) using a cell-free extract of Enterobacter cloacae and chemo synthesis by sodium borohydride (NaBH 4 ) on biofilm-forming Pseudomonas oryzihabitans. Antimicrobial effect of silver nanoparticles in both types and in combination with imipenem were evaluated by agar well diffusion method. The results revealed a good response to inhibit biofilm-forming Pseudomonas oryzihabitans growth by silver nanoparticles antibacterial activity in both types (biological and chemical) and in combination with imipenem; the antimicrobial effect was increased and enhanced. In the present study, it was found that the biological and chemical silver nanoparticles were considered a novel and decisive solution against biofilm and multi-drug resistance bacteria with a preference of biological silver nanoparticles.

Neisseria gonorrhoeae is a member of the Neisseriaceae family. They are non-spore-forming, gram-negative, encapsulated, non-motile, non-acidic, and bean-shaped bacteria. This study included 40 men that presented chronic and recurrent infection with N. gonorrhoeae virus. The initial infection of this virus was detected using a rapid bacterial antigen immunoassay and confirmed using enzyme-linked immunosorbent assay (ELISA ). The mean age of the study group was 36.71±12 (mean±) years. Men between the age of 20-49 years were the most affected by N. gonorrhoeae infection, and displayed a significantly lower average sperm count than the healthy individuals upon semen examination. The percentage of sperms with slow motility, total number of dead sperms, and abnormal- shaped sperms were some significant phenotypes observed in the infected individuals as compared to that in the healthy controls. In this study, we found that the bacterium, N. gonorrhoeae could cause erosion of the mitochondrial DNA of sperms in the semen of the infected individuals. In addition, using the gap-PCR technique, it became evident that the infected individuals portraying altered sperm characteristics as mentioned above, showed increased number of common deletion (4, 977 base pairs) in the sperm mitochondrial (mt)-DNA. Hence, our results imply that N. gonorrhoeae infection can lead to a common deletion of 4,977 bp in sperm mt–DNA, which can in turn cause male sterility.

The current study was aimed to detect the existence of genes encode outer membrane proteins: transfer protein (traT) and increased serum survival (iss) which associated with resistance to complement bacterial lysis activity in different Enterobacteriaceae species isolates .Enterobacteriaceae isolates included in this study were (5) isolates of E. coli , K. pneumonia, Salmonella typhi and Shigella dysentery, (4) isolates of Proteus vulgaris and (2) isolates of Serratia marcescens which were isolated from different clinical infections. The traT and iss genes were revealed from whole DNA of 26 isolates of Enterobacteriaceae family, it was found that 21(80.7%) of Enterobacteriaceae isolates gave positive result for traT gene at 288bp while only 17(65.3%) of isolates gave positive result for iss gene at 258bp. It was observed that the traT gene was recognized among 100 % of Salmonella typhi and Serratia marcescens strains and the prevalence of a traT gene was showed among 80 % of K. pneumoniae and Shigella dysentery isolates whereas 75% of Proteus vulgaris and 60% of E. coli isolates contain the traT gene. The iss was found among 80% of both E. coli and Shigella dysentery isolates while it was observed in 60% of K. pneumonia and Salmonella typhi isolates and it was present only in 50% of Proteus vulgaris and Serratia marcescens isolates, as conclusion the study confirmed presence of traT and iss which linked to human complement resistance among local Enterobacteriaceae species and high rate of occurrence among extraintestinal isolates. .

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