Crude cell extracts of 26 isolates of Salmonella serotype typhi (S. typhi) and 48 other Salmonella isolates representing 28 serotypes and seven DNA hybridization subgroups were analyzed for electrophoretic variants of 24 metabolic enzymes by starch gel electrophoresis. Ail strains of S. typhi had identical isoenzyme patterns, indicating that they were a single clone. All of the enzymes detected in the remaining strains were polymorphic, and the degree of genetic variation was quite high. The average number of alleles per enzyme locus was 4.7, and the mean genetic diversity per locus was 0.556. Thirty-two distinct allele profiles, or electrophoretic types (ETs), were found in these 48 strains of Salmonella serotypes other than S. typhi. Analysis of the genetic relationships of the ETs to each other showed that, with one exception, the ETs formed subgroups that were consistent with the subgroupings based on DNA hybridization studies. ET profiles were not always linked to specific serologic patterns. These data show that multilocus enzyme electrophoresis has a potential application in epidemiologic and taxonomic studies of salmonella, although it is not differential for S. typhi. We also propose a new species, Salmonella bongori comb. nov., a new combination based on the elevation of Salmonella choleraesuis subsp. bongori to the level of species.

Of 93 strains of Staphylococcus aureus isolated from inpatient wards of Ismailia General Hospital, 48 (51 %) were proven to be methicillin resistant (MR). Of these MR S. aureus strains, 44 were isolated from patients and 4 were isolated from healthy carriers, who were newly arrived interns working in the same wards. Bacteriophage patterns of MR S. aureus were identified by using routine test dilution (RTD) and 100-fold dilutions (100 RTD) of phages. Of these 48 strains, 37 (75%) (33 from patients and 4 from interns) were nontypeable when using RTD and 100 RTD of phages. Of the other 11 strains, 8 were nontypeable by RTD of phages, but 5 of them had the phage pattern D11/1136 when tested by 100 RTD. Three strains had the phage pattern 3A/3C/55/71, and three strains had different phage patterns, 29/81, 96, and 95/D11. The finding of colonization with virulent MR S. aureus strains in interns working on the wards in which these patients were located suggested that new strategies for control of MR S. aureus nosocomial infections must be considered and evaluated.

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There is growing interest in platelets concentrates contribution to antimicrobial host defense functions. Objective: This study aims to investigate the in vitro antimicrobial and antibiofilm properties of platelet rich plasma (PRP) and platelet gel (PG) against S. aureus isolates recovered from Surgical Site Infections (SSIs). Methodology: A total of 200 SSI specimens were collected. S. aureus isolates were identified and biofilm producers were detected by modified tissue culture plate method. The isolates were checked for antibiotic susceptibility by Kirby-Bauer disc-diffusion method. Alamar blue (AB) susceptibility assay was applied to test the killing effect against planktonic and biofilm cultures of S. aureus. Time kill assay was performed during 24 hours period. Results: Out of 40 S. aureus isolates, 80% were biofilm producers which show more resistance to antibiotics than non-biofilm producers. However, there was non-significant difference between the effect of platelet poor plasma (PPP), PRP and PG between biofilm and non-biofilm producing planktonic S. aureus. Using AB assay, the viability of S. aureus within biofilm was reduced by 28%, 29% and 46% after 24 hours of treatment with PPP, PRP, and PG respectively. In time kill assay, bacterial count was reduced after 2 and 4 hours and was increased again after 24 hours. PG and PRP had more significant antimicrobial effect than PPP. PG had more significant antimicrobial effect than PRP. Conclusion: Antimicrobial effect of PG is more potent than PRP against S. aureus and both components have similar antimicrobial effect on biofilm and non-biofilm producing S. aureus.

Health crisis of Multi-drug resistant gram negative bacilli (MDRGNB), including Enterobacteriaceae, seems overwhelming as its worldwide spread causes clinical failure in the therapeutic care of diseases by these pathogens and results in significant morbidity and mortality. Combination therapy, using two or more drugs, may be the last resort for treatment of these multi-drug resistant (MDR) organisms. Objective: to update the antibiotic policy to improve treatment of MDR Enterobacteriaceae infections and to reduce morbidity and mortality rates due to these infections. Methodology: Out of 219 of Enterobacteriaceae strains isolated from different types of infections in Suez Canal University Hospitals (SCUHs), 48 isolates (21.91%) were proved to be MDR, including resistance to imipenem. In vitro assessment of Imipenem-colistin combination on the MDR-Enterobacteriaceae strains was performed using the checkerboard technique. Results: The combination had a synergistic effect on 63.04% of the isolates and additive effect on 23.9%. Indifferent effect was shown in 10.8%, while antagonism was shown in 2.1% of the strains. At least, four-fold reduction in imipenem MIC was proved in 86.9% of the strains, 30.43% turned to be imipenem sensitive with drop of their MICs from ≥ 4 to ≤ 1μg/ml, 15.21% changed to intermediate resistance with MIC decrease from ≥ 4 to 2 μg/ml. Three of the 5 strains that showed indifference and the only strain which showed antagonism were colistin resistant strains. Conclusion: High rates of synergy, in addition to reversal of imipenem resistance, were reported by colistin -imipenem combination against MDR-Enterobacteriaceae, which may encourage clinical trials of combination therapy in treatment of Hospital acquired infections (HAI) by MDR pathogens. METHODOLOGY Study population:This is a quasi experimental study carried out during the period from December 2017 to November 2018. Forty eight carbapenem resistant Enterobacteriaceae were isolated from 272 patients admitted to different wards in SCUHs. Patients were of both sex, and from all