Seroprevalence of occult hepatitis B among Egyptian paediatric hepatitis C cancer patients.

Occult hepatitis B infection is characterized by the presence of hepatitis B virus (HBV) DNA in the serum in the absence of hepatitis B surface antigen (HBsAg). Prevalence of hepatitis C virus (HCV) infections in Egypt is among the highest in the world. In this study, we aim at analysing the rates of occult HBV infections among HCV paediatric cancer patients in Egypt. The prevalence of occult HBV was assessed in two groups of paediatric cancer patients (HCV positive and HCV negative), in addition to a third group of paediatric noncancer patients, which was used as a general control. All groups were negative for HBsAg and positive for HCV antibody. HBV DNA was detected by nested PCR and real-time PCR. HCV was detected by real-time PCR. Sequencing was carried out in order to determine HBV genotypes to all HBV patients as well as to detect any mutation that might be responsible for the occult phenotype. Occult hepatitis B infection was observed in neither the non-HCV paediatric cancer patients nor the paediatric noncancer patients but was found in 31% of the HCV-positive paediatric cancer patients. All the detected HBV patients belonged to HBV genotype D, and mutations were found in the surface genome of HBV leading to occult HBV. Occult HBV infection seems to be relatively frequent in HCV-positive paediatric cancer patients, indicating that HBsAg negativity is not sufficient to completely exclude HBV infection. These findings emphasize the importance of considering occult HBV infection in HCV-positive paediatric cancer patients especially in endemic areas as Egypt.

Antimicrobial activities against biofilm formed by Proteus mirabilis isolates from wound and urinary tract infections.

BACKGROUND: Bacterial species are capable of living as biofilm and/or planktonic forms. There is increasing evidence for the role of bacterial biofilm in various wound and urinary tract infections (UTIs). The aim of the present study was to evaluate the ability of the bacteria, isolated from urinary tract infections (UTIs) and wound infections, to form biofilm and correlate the role of biofilm with their antimicrobial resistance. MATERIALS AND METHODS: All the isolated bacteria were screened for their ability to form biofilm using the microtitre plate method. RESULTS: Wound isolates of Staphylococcus aureus and Enterobacter sp. had more biofilm forming capacity than the UTI isolates. Proteus mirabilis isolates were among the strongest biofilm forming bacteria and were chosen for antimicrobial study. In sub-MIC concentrations of antimicrobial agents used, ciprofloxacin was found to be the most effective in decreasing biofilm formation. On the other hand, ceftriaxone and ciprofloxacin were effective in partial removal of preformed biofilm biomass. CONCLUSION: Ciprofloxacin was more effective in killing bacterial cells especially at high antimicrobial concentrations that could be reached in urine levels and can be used in impregenating catheters.

Amplification of Proteus mirabilis chromosomal DNA using the polymerase chain reaction.

A Proteus mirabilis-specific polymerase chain reaction (PCR) was developed and standardized. The origin of the primers was a recombinant clone that contained P. mirabilis-specific Hind III fragment DNA of 3.5-kilobase pairs. Based on the sequence data of P. mirabilis recombinant clone, two primers designated MMKAP 1 and MMKAP 2 were synthesized for use in the PCR. A P. mirabilis-specific 3.5-kb pair DNA product was amplified by the primers from 18 strains of P. mirabilis, but not from other Protease species and bacteria. The minimum amount of target DNA detected by P. mirabilis PCR was 10 fg using ethidium bromide/ultraviolet exposure of gels or Southern blot hybridization with a P. mirabilis recombinant DNA probe.

Effect of lipopolysaccharide on mitogen-activated protein kinases and cytosolic phospholipase A2.

The addition of platelet-activating factor (PAF) to human neutrophils increases phosphorylation on tyrosine residues and stimulates the activity of p42erk2 mitogen-activated protein kinase (MAP kinase). This action is rapid and transient. In contrast, p42erk2, p44erk1 and the p40hera MAP kinase isoforms are all not tyrosine phosphorylated or activated in human neutrophils stimulated with low concentrations of lipopolysaccharide (LPS) in combination with serum. In spite of this, the PAF-induced tyrosine phosphorylation and activation of the p42erk2 MAP kinase are greatly potentiated in cells pretreated with LPS. More interestingly, although low concentrations of LPS do not affect MAP kinase isoforms in these cells, they cause the phosphorylation of cytosolic phospholipase A2 (cPLA2), as evidenced by a decrease in the electrophoretic mobility of the enzyme. In addition, this stimulus-induced upward shift in the mobility of the enzyme is not inhibited by the tyrosine kinase inhibitor, genistein. Furthermore, LPS increases the release of arachidonic acid in control and PAF-stimulated human neutrophils. These observations clearly show that cPLA2 can be phosphorylated and activated by kinases other than the currently known MAP kinases. It is proposed that there are MAP kinase-dependent and -independent mechanisms for the phosphorylation of cPLA2.

Microbial contamination of cosmetics and personal care items in Egypt--body lotions and talcum powders.

We examined a total of 54 samples, including 18 body lotions and 36 talcum powders, for their total aerobic bacterial, coliform and fungal counts. We also carried out anaerobic bacterial counts for talcum powder as well as tests to detect some potentially hazardous bacteria in all tested samples. Talcum powders were more heavily contaminated with bacteria and fungi than body lotions. More than 40% of the tested body lotions contained no viable bacteria or less than 100 c.f.u./g. while all the talcum powders tested contained more than 100 c.f.u./g. Thirty per cent of the talcum powders were contaminated with 10(4) c.f.u./g. and none of the body lotions were contaminated to that extent. No coliforms were recovered from any of the body lotions, while 17% of the talcum powder examined contained coliforms in the range of 230-500 c.f.u./g. Staphylococcus spp. were detected in 18 samples of both talcum powders and body lotions, three of these Staphylococci were of the aureus type. Three samples of talcum powder contained E. coli, two samples contained Enterobacter agglomerans and one sample contained Citrobacter freundii. Seventy per cent of the body lotions showed no fungal counts, while 83% of the talcum powders examined were contaminated with fungi and most of the contaminated talcum powders contained more than 100 fungal cells/g. With regard to the anaerobic bacterial counts for talcum powders, 50% of the samples showed no counts while the other 50% contained less than 100 c.f.u./g. Four samples were contaminated with Clostridium perfringens, although C. tetani was not recovered from any of the samples.

Microbial contamination of cosmetics and personal care items in Egypt--eye shadows, mascaras and face creams.

We examined a total of 150 samples, including 27 eye shadows, 27 mascaras and 96 face creams, for their microbial contents. Mascaras were generally more contaminated than eye shadows. More than 75% of the examined eye shadows contained fewer than 100 c.f.u./g aerobic bacterial count compared to 63% of the mascaras examined. Viable bacteria were not recovered from 61% and 48% of the eye shadows and mascaras respectively. While 4% of the eye shadows were heavily contaminated (contained more than 10(4) c.f.u./g), 15% of the mascaras were as heavily contaminated (with more than 10(4) c.f.u./ml of bacteria). Face creams were generally more heavily contaminated than eye shadows and mascaras. More than 70% of the examined creams contained more than 100 c.f.u./g of bacteria compared to 23% and 37% of eye shadows and mascaras respectively. Only 5% of the face creams were heavily contaminated. However, 27% of the creams were contaminated with more than 10(3)-10(4) c.f.u./g of bacteria compared to none in this range for both eye shadows and mascaras. Qualitative tests for detection of hazardous bacteria showed that none of the eye shadows were contaminated with any of those micro-organisms. Out of nine items of a specific brand of mascara, three isolates of Pseudomonas aeruginosa, one isolate of Citrobacter freundii and one isolate of Klebsiella pneumonia were detected. Among the creams, two brands showed the highest contamination levels with more than 85% of the tested samples containing more than 10(3) c.f.u./g fungi and at least 10(4) c.f.u./g bacteria.(ABSTRACT TRUNCATED AT 250 WORDS)

Microbial contamination of cosmetics and personal care items in Egypt--shaving creams and shampoos.

We examined a total of 192 samples, including eight different brands of shaving cream and eight brands of shampoo, for their total aerobic bacterial, coliforms and fungal counts. Shaving creams were more heavily contaminated with bacteria than shampoos. Viable bacterial were not recovered from 57% and 10% of shampoos and shaving creams, respectively. Only 3% of shaving creams were heavily contaminated with more than 10(4) c.f.u./g, while none of the shampoos contained such a high number of bacteria. With regard to the medium range contamination levels, 52% of shaving creams showed bacterial counts ranging from 10(2) to 10(3) c.f.u./g or ml, compared to 15% of shampoos which were contaminated to the same level. Fourteen per cent of shaving creams were contaminated with greater than 10(3)-10(4) c.f.u./g or ml, compared to 1% of the shampoos. No coliforms were recovered from either the shaving creams or the shampoos; however, Staphylococcus spp. were detected in six samples of both shampoos and shaving creams. Some of these Staphylococci, were aureus type. One isolate of Pseudomonas aeruginosa was also detected in a sample of shampoo. The incidence of fungal contamination was much less than the bacterial contamination. No viable fungi were recovered from 88% and 76% of the shaving creams and shampoos, respectively. The majority of the remaining samples, for both products, were contaminated with less than 100 fungal cell/g or ml. The pH of all the tested samples was alkaline (pH 7.2-9), which is well known to inhibit fungal contamination.

Microbial contamination of a hexetidine mouth wash.

Twenty different bottles of a mouth wash containing 0.05% hexetidine as an active ingredient were examined for their microbiral contents. The results showed that all the tested bottles were contaminated with bacteria. Nine out of the twenty bottles contained more than 10(4) CFU/ml. Staphylococcus aureus was detected in one bottle, while Pseudomonas species were found in four bottles. Fungi were detected in 10 bottles, a fungal count of more than 100 fungus/ml were found in 12 out of the 19. Yeasts were detected in 16 bottles, Candida species were the most predominant with a rate of 11 out of the 16, while Saccharomyces species were found in 5 out of the 16. C. albicans, a definite oral pathogen, was found in 3 bottles.

Effect of agar percentage, agar thickness, and medium constituents on antibiotics assay by disc diffusion method.

The factors affecting the sensitivity of nafcillin, vancomycin, oleandomycin, chloramphenicol, methacycline and novobiocin assay, using the paper disc diffusion method, were studied. Agar concentration and pour volume were found to influence the assay sensitivity of antibiotics. The type of assay medium was effective e.g. brain heart infusion agar was the best medium for nafcillin and methacycline; synthetic amino acid medium for oleandomycin; Muller Hinton agar for vancomycin and chloramphenicol; and G & R medium for novobiovicin. All additives, including inorganic ions, sugar, organic acids, complexing agents, surface active agents and blood, decreased the activities of the studied antibiotics. Higher activities of vancomycin, methacycline were observed at pH = 5, of nafcillin, chloramphenicol, and novobiocin at pH = 6, and of oleandomycin at pH = 7.