Impact of biofilm production in methicillin resistant Staphylococcus aureus among diabetic foot patient

Background: Diabetic Foot Infection poses many problems in clinical practice. It is usually polymicrobial, and Staphylococcus aureus is the most common pathogen isolated

Objective: To determine the prevalence of methicillin resistant S. aureus [MRSA] and MRSA biofilm production among diabetic patients with chronic leg ulcers

Methodology: This study included 150 patients suffering from infected diabetic foot ulcers. We used VITEK 2 system to identify isolated bacteria. Colonies of S. aureus were screened for resis¬tance to methicillin on Mueller–Hinton agar supplemented with oxacillin at 4 µg/mL Antibiotic sensitivity test was investigated using Kirby Bauer Disc Diffusion method. Investigation of biofilm formation was performed by tissue culture plate method. Detection of icaA and icaD genes was investigated by PCR

Results:S. aureus was isolated from 70 [46.6%] patients. Among the 70 S. aureus, 34 [22.6%] were [MRSA], Pseudomonas aeruginosa 36[24.0%], Klebseilla pneumoniae 25[16.6%] and E.coli were 19[12.6%]. Twenty eight out of 34 tested MRSA [82.35%] were able to form biofilm.Twenty five isolates [73.3%] were strong biofilm former, 3 isolates [8.8%] were moderate biofilm producer and 6 isolates [17.6%] were non biofilm producers. Twenty two were positive for both icaA and icaD genes, On the other hand eight isolates were negative for both genes

Conclusion: A high prevalence of biofilm producing MRSA was detected in S. aureus isolated from patients with Diabetic foot

Conjunctival microbiota and antibiotic resistance pattern in patients submitted to cataract surgery and antibacterial activity of some plant essential oils

The objective of this study was to identify the conjunctival microbiota of patients undergoing cataract surgery and evaluate its antibiotic resistance pattern. Also to in-vitro evaluate the antimicrobial effects of some essential oils against multidrug resistant isolates. Ocular samples were collected using swabs and polymethyl-metaacrylate [PMMA] intraocular lenses from seventy patients submitted to cataract surgery. Isolation and identification of bacteria was performed using conventional microbiological methods. Antibiotic sensitivity was done by disc diffusion method. The sensitivity of 16 essential oils against isolated bacteria was tested using well diffusion method. Thirty six strains were isolated from patients submitted to cataract surgery. Gram positive microorganisms represent 75% of the isolates with coagulase-negative Staphylococci [CoNS] the most common isolate [47.2%] followed by S.aureus [19.4%], whereas gram negative occurred in 25% of cases, with Moraxella spp. the most frequent Gram negative isolate. Antibiotic sensitivity test revealed that the highest antibiotic resistance was exhibited against ceftazidime [100%] followed by clindamycin [86%], ampicillin [80.5%], erythromycin [72.2%] and tetracycline [69.4%]. Gentamycin displayed the best activity [55.5%] followed by chloramphenicol [44.4%] and vancomycin [38.88%]. Fifteen essential oils showed antibacterial effect against one or more bacterial strains. The most potent oils were peppermint oil, dill oil, cinnamon oil which showed promising inhibitory activity against most tested bacterial species, whereas cotton, ginger, chamomile, blue green, cod liver and parsley oil were the least active against tested strains. Olive oil failed to inhibit any of the tested strains. In general, St. pneumoniae was the most susceptible organism as it inhibited by ten oils. Our results indicate a promising antibacterial effect of peppermint oil, dill oil and cinnamon oil against conjunctival microorganisms

Physiological and biochemical studies on phytopathogenic bacteria isolated from cucumber in Egypt

Thirty phytopathogenic bacterial isolates were obtained from diseased cucumber plants [Cucumis sativus]. These isolates were highly pathogenic, capable of inducing angular leaf spots as well as wilting of cucumber seedlings within 3-6 days after inoculation. The diagnostic tests including colony morphology, pathogenicity trials and different physiological tests showed that they belonged to Pseudomonas syringae pv lachrymans. Inoculating three weeks old cucumber seedlings with the most virulent isolate resulted in a reduction in dry weight, water content and both shoot and root length to a level below that of the control

Rational approach towards improving the predictive effectiveness of official antimicrobial challenge tests

Comparative resistance of naturally occurring strains of Pseudomonas aeruginosa and E. coli and type cultures of the same species to the preservatives was assessed. Some of the factors affecting their responses were also examined. The results indicated that minimum bactericidal concentration value [MBC] of E. coli ATCC 8739 and Pseudomonas aeruginosa ATCC 9027 were much lower than those of the environmental strains. This suggested that type culture organisms should be cultivated in conditions relevant to actual environmental in the pharmaceutical and cosmetic production field where they are subjected to starvation and many other stresses. The comparison between the usual pharmacopoeial cultivation method and multinutrient starved in different dilutions of trypticase soy agar showed that starved organisms had much higher D-values. The D-values of starved organisms increased with increasing of TSB dilution up to 10[-3]. Most air conditioned area in production field are adjusted at 20-25°C. Growth of starved organisms at 23°C showed highest homogeneous antimicrobial response curve. Thus this study suggested usage of multinutrient starved organisms. The results showed that the starved type culture strains were more aggressive than strains isolated from contaminated batches of the above products or from their water for preparation. While the nutrient amended ATCC type strains showed the least aggressiveness ability. The significance of these findings may alter the present concept of preservation testing systems as well as routine control procedures in cosmetic and pharmaceutical preparations

Effect of sulphur pollutants on some enzymatic activities of streptomyces Rimosus

Some enzymatic activities of Streptomyces rimosus, grown in media containing different concentrations of inorganic sulphur compounds were examined. It seems that exopeptidases were very highly stimulated by sulphite or persulphate, followed equally by thiosulfate or sulphate whereas sulphide was inhibitory. Persulphate induced the maximum activity of endopeptidases, followed by sulphate whereas sulphite exerted no effect, while either thiosulfate or increased with state of oxidation of the sulphur source, though sulphite ion exerted the least effect and induced the maximum stimulation for alkaline phosphatase activity followed by thiosulfate and least by the other sources. Dithionates seemed to be more effective in stimulating GPT than monothionates especially at the higher state of oxidation. GOT activity was hardly affected by the lower concentrations of the sulphur source except sulphate ions that were remarkably stimulatory, followed by sulphite ions. Higher concentrations of the sulphur sources equally enhanced GOT activity