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Giuseppe A Botta

Publications and source records attributed to Giuseppe A Botta.

10 recordsLinked to original sources
PubMed2006

Clinical relevance of virulence genes in Campylobacter jejuni isolates in Bahrain.

There are no data describing the genetic make-up of Campylobacter strains (an important aetiological agent of diarrhoea) circulating in the Arabian Gulf region. Here, the molecular characterization of two virulence genes in Campylobacter jejuni from Bahrain and the relationship with clinical infection are reported. Molecular screening for cytolethal distending toxin (cdtB) and invasion-associated marker (iam) genes was carried out on C. jejuni stool isolates collected from January 2002 to January 2004 in Bahrain. The molecular characterization was correlated with the patients' socio-demographic and clinical parameters. Of the 96 C. jejuni strains tested, 50 (52 %) were cdtB+/iam+, 30 (31 %) were cdtB+/iam- and 16 (17 %) were cdtB-/iam-. Sixty-nine per cent (66/96) of patients were less than 3 years old, with significantly higher detection of cdtB+/iam+ and cdtB+/iam- strains (P < 0.001 and P < 0.01, respectively) in this age group. Seventy patients (73 %) were symptomatic. In the group that were less than 3 years old, 62 and 85 % of those with cdtB+/iam+ and cdtB+/iam- strains, respectively, were symptomatic compared with 100 % for those over 3 years of age. However, the presence of cdtB-/iam- strains still resulted in clinical infection in the children under 3 years but not in the older patients. This is the first report describing the molecular characterization of virulence genes in Campylobacter isolates from this region. The findings indicate that strains of different virulence genetic make-up are circulating in the population, with children under the age of 3 years being most vulnerable. Further work on the molecular characterization, gene expression and determination of the invasive phenotypes of C. jejuni strains circulating in different regions is needed.

Adolescent↗
PubMed2006

Neonatal sepsis 1991-2001: prevalent bacterial agents and antimicrobial susceptibilities in Bahrain.

OBJECTIVES: To investigate the organisms causing neonatal sepsis and their modifications over an extended period, to assess their changing sensitivities to antibiotics and to verify whether the policy for screening pregnant women for group B streptococci (GBS) carriage is desirable in our settings. SUBJECTS AND METHODS: Medical records of all infants with positive blood culture from the Neonatal Intensive Care Unit at Salmaniya Medical Complex between 1991 and 2001 and Bahrain Defense Force Hospital between 1999 and 2001 were reviewed. RESULTS: Of the 7,978 neonates in both hospitals 335 (4.19%) had culture-proven bacteremia. Gram-positive bacteria were isolated at constant rate over the 11-year period. The main agents isolated were coagulase-negative Staphylococcus (CoNS) in 138 cases (41%), Staphylococcus aureus in 28 newborns (8%) and GBS in 26 patients (7.8%, 0.2/1,000 live births). All of them were sensitive to penicillin G, erythromycin and clindamycin. Gram-negative bacteria were declining but Escherichia coli was isolated in 35 cases (10%). Of special concern is the increasing percentage (5.7%) of Candida isolation. No clear trend toward increasing resistance was observed, although a major difference among the two institutions was evident. Klebsiella and Enterobacter spp. showed resistance to many of the antibiotics tested, thereby posing difficult therapeutic choices. CONCLUSION: Good quality specimens are essential to evaluate the role of CoNS. The increasing threat of fungal infection must be carefully tackled. Specifically tailored policies for GBS prevention must be defined according to the local epidemiology.

Bahrain↗
PubMed2006

Human papillomavirus infection among women attending health facilities in the Kingdom of Bahrain.

OBJECTIVE: To investigate the occurrence of human papillomavirus (HPV) infection and the associated risk factors in Bahrain's female population. METHODS: This study was carried out between March to December 2004, which includes cervical scrapings for Pap smear and HPV-DNA testing using polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analysis, obtained from 100 women attending the Gynecology Clinic at Salmaniya Medical Center and Sheikh Sabah Health Center in the Kingdom of Bahrain. We distributed questionnaires that include the sociodemographic data as well as information on risk factors such as smoking, parity, and the contraceptive used. RESULTS: Eleven women (11%) with normal cytology were HPV-positive. The RFLP analysis detected HPV-types 16, 18, 45, 62 and 53. Positive women were significantly older (43.3 +/- 10.1 years) than negatives (36.5 +/- 9.9 years; p=0.04), however, there was no difference in age of first sexual contact (positive: 18.1 +/- 5.7 years versus negative: 20.6 +/- 4.4 years). Polygamy, smoking and hormonal contraception was not identified as risk factors, but positive women showed higher parity. CONCLUSION: In this study on HPV infection in Bahrain, the 11% positivity with high risk HPV types, in the presence of normal cytology suggests that in addition to the cervical cancer screening program, offer of HPV testing deserves consideration.

Adult↗
PubMed2004

Effect of antibiotic sub inhibitory concentration on cytolethal distending toxin production by Campylobacter jejuni.

OBJECTIVES: To investigate the effect of pre-exposure antibiotics on cytolethal distending toxin (CDT) production and toxigenic effect of C. jejuni. METHODS: Sonicates and filtrates were prepared from known cdt+ and cdt- isolates of C. jejuni which had been pre-exposed to varying concentrations (MIC, 1/2 MIC, 1/4 MIC, 1/8 MIC) of erythromycin and ciprofloxacin. The CDT toxigenic effect was examined using INT 407 and HeLa cells. RESULTS: A trend of increased toxigenic effect was observed with pre-exposure to antibiotics. This was more pronounced with erythromycin pre-exposure compared to ciprofloxacin. Although a trend of increasing toxigenic effect with decreasing antibiotic concentration was demonstrable, some differences were observed between isolates. In one isolate the increased toxigenic effect was statistically significant (P<0.05) at 1/4 MIC in INT 407 cells and at 1/8 MIC in HeLa cells. CONCLUSIONS: This study provides evidence of an association between CDT production by C. jejuni and pre-exposure to antibiotics. Pre-exposure to ciprofloxacin and erythromycin at concentrations below MICs could potentiate CDT activity. Further work is needed to elucidate the mechanism involved. We recommend that these antibiotics be used in the treatment of C. jejuni enteritis only when strongly indicated and with careful monitoring of patients.

Anti-Bacterial Agents↗
PubMed2004

Induction of alpha and beta chemokines by intestinal epithelial cells stimulated with Campylobacter jejuni.

OBJECTIVES: To investigate the production of dynamic alpha and beta chemokines represented by interleukin-8 (IL-8) as alpha chemokine and CCL2 (monocyte-chemoattractant protein-1, CCR2 ligand), CCL4 (macrophage-inflammatory protein-1beta, CCR5 ligand), CCL3 (macrophage-inflammatory protein-1alpha, CCR1/5 ligand), (CCL5, regulated upon activation, normal T-cell expressed and secreted (RANTES, CCR5 ligand) as beta chemokines by the human intestinal cell line INT407 stimulated with factors produced by living Campylobacter jejuni (C. jejuni) and those present within sonicated and filtrated bacteria. METHODS: We used immunohistochemical technique modified to detect intracellular production of cytokines protein and RT-PCR to read RNA messages for evaluation of de novo cytokine synthesis. RESULTS: Living bacteria induced increased numbers of IL-8, CCL4 and CCL2 but not CCL3 or CCL5 producing cells. Low numbers of IL-8, CCL4 and CCL2 producing cells were detected with filtrated supernatant compared to living and sonicated bacteria. A non-significant low number of chemokine producing cells was noted when comparing numbers of chemokine producing cells stimulated with living C. jejuni to those stimulated with sonicated bacteria, indicating that the triggering factors involved in stimulation with living bacteria were still active after sonication, but they were largely lost upon filtration. The mRNA signals for IL-8 were noted in conformity with its protein levels as increased IL-8 mRNA signals were registered after stimulation with living and sonicated bacteria but not with filtrated supernatant. CONCLUSIONS: Preferential production of chemokines probably induced by membrane associate factors of C. jejuni acting on intestinal epithelial cells is presented. These chemokines are suggested to be part of an inflammatory network affecting cell types that contribute to initiation and/or resolution of the infection.

Analysis of Variance↗
PubMed2003

Campylobacter-stimulated INT407 cells produce dissociated cytokine profiles.

OBJECTIVES: To study the action of factors produced by living Campylobacter jejuni (C. jejuni) against those present within sonicated and filtrated bacteria on induction of potential cytokines by the human intestinal cell line INT407. METHODS: We used immunohistochemical technique modified to detect intracellular production of cytokines protein and RT-PCR to read RNA messages for evaluation of de novo cytokine synthesis. RESULTS: The data herein display dissociation of cytokine profiles induced on by living C. jejuni. Exposure of INT407 cells to 10(6) live bacteria showed the highest numbers of cytokine producing cells of all examined cytokines. IFN-gamma was the highest induced cytokine followed by IL-10, TNF-alpha and lastly IL-4. Also, abrogation of induction of the proinflammatory cytokines IFN-gamma and TNF-alpha but not the antiinflammatory cytokines IL-4 and IL-10 by sonicated and filtrated bacteria was depicted. At the mRNA level, TNF-alpha signals were noted in accordance with its protein levels since increased TNF-alpha mRNA signals were registered only after stimulation with living bacteria. Very low or no induction of TNF-alpha was registered with non-stimulated cells. CONCLUSIONS: These results illustrate for the first time a role for factors from living bacteria in directing the immune response towards Th1 type. Characterization of such factors may be essential for future immunotherapeutic interventions during severe bacterial infections.

Campylobacter jejuni↗
PubMed2002

Causative pathogens of severe diarrhea in children.

OBJECTIVES: To investigate the enteropathogens in children with diarrhea attending Salmaniya Medical Complex, Bahrain. METHODS: Fecal samples from 805 children up to 15 years were examined for parasites, ova and cysts by direct wet preparation, formol-ether concentration and modified Ziehl-Neelsen stain, during the period November 1998 through to June 2000. Samples were cultured for Salmonella, Shigella, Campylobacter and Enteropathogenic Escherichia coli. Antibiotic sensitivity tests were performed on the relevant clinical isolates by agar disk diffusion method. All stools from children below 3 years of age (653 samples) were processed for adenovirus and rotavirus using a commercially available latex agglutination test (Diarlex). In addition, reverse transcription-polymerase chain reaction was performed on 200 randomly selected samples using oligonucleotide primers for Rotavirus A, B and C. RESULTS: Four subjects were found positive for parasites. Eighty-three (10.3%) samples were found positive for Salmonella (46 isolates), Shigella (26 isolates), Campylobacter jejuni (7 isolates), and Enteropathogenic Escherichia coli (4 isolates). Rotavirus was found in 91 (13.9%) samples and 4 samples (0.6%) were found positive for adenovirus. Out of 200 samples examined by reverse transcription-polymerase chain reaction, 73 (36.5%) were positive for group A rotavirus. CONCLUSIONS: Rotavirus type A appeared to be the most common single agent in our pediatric population, followed by the classical bacterial pathogens. Adenovirus and parasites appeared to play a very minor role in diarrhea. Thus, we suggest the introduction of rotavirus diagnostic tests in microbiological examination of diarrheic stools of children below 3 years of age.

Adolescent↗
PubMedDate not supplied

Status of malaria in the Kingdom of Bahrain: a 10-year review.

BACKGROUND: Malaria was eradicated in Bahrain about 20 years ago. However, because of a large immigrant population, cases of imported malaria continued to be seen. This paper presents an evaluation of the data from 1992 to 2001 to assess the levels of indigenous and imported malaria cases and the potential for reemergence of malaria transmission in the country. METHODS: Epidemiologic and parasitologic data on confirmed malaria cases during the review period were analyzed. Data on vector breeding activity were also analyzed to determine the potential for reemergence of local transmission. RESULTS: From 1992 to 2001, 1,572 cases of malaria were reported. All were imported malaria cases. There was a consistent decline in the number of cases, from 282 (the peak level) in 1992 to 54 in 2001. Eighty-four percent (1,318/1,572) of infections were contracted as a result of travel to or previous domicile in five countries, namely India, Pakistan, Sri Lanka, Bangladesh and Sudan. Plasmodium vivax was the etiologic agent in 85.6% (1,346/1,572) of cases, with Plasmodium falciparum accounting for 14% (220/1,572). During this period, the percentage of examined breeding sites where Anopheles mosquito larvae were identified remained fairly constant, ranging between 0.05% and 0.1%. CONCLUSIONS: From 1992 to 2001, there was a consistent decline in the number of imported malaria cases in Bahrain. There were no cases of locally acquired malaria during this period. The low level of vector breeding spots with Anopheles mosquito larvae suggests that the potential for reemergence of local transmission remains low.

Animals↗