Giuseppe Botta | Università degli Studi di Udine / University of Udine (original) (raw)

Papers by Giuseppe Botta

Research paper thumbnail of Human papillomavirus infection among women attending family planning clinic in Nigeria: prevalence, correlates, and co-infection withChlamydia trachomatis

Journal of Immunoassay and Immunochemistry, 2018

Infection with high-risk genotypes of human papillomavirus (HPV) is considered the main cause of ... more Infection with high-risk genotypes of human papillomavirus (HPV) is considered the main cause of invasive cervical. A number of epidemiologic studies have suggested that HPV and Chlamydia trachomatis (CT) play a synergistic role in the etiology of cervical intraepithelial neoplasia and subsequent cervical cancer. The current study aimed to evaluate the HPV prevalence and the risk factors for co-infection with CT among women attending family planning clinic in Nigeria. Following enrolment, 90 patients were screened for IgG antibodies to virus-like proteins of HPV types 6, 8, 16, and 18. CT seropositivity was tested by enzyme-linked immunosorbent assay for the detection of IgG and IgM antibodies. The prevalence of HPV IgG was 20%. Seropositivity for CT IgM was 77.8% while the IgG was 0%. A total of 10 women (11.1%) were seropositive for both CT IgM and HPV IgG antibodies. Seropositivity for HPV IgG was significantly associated with age at marriage (P < 0.001), current Chlamydia infection (P < 0.011), and number of children (P < 0.025), while seropositivty for HPV IgG and Chlamydia trahomatis IgM was significantly associated with age at coitarche (P < 0.028), number of life sex partners (P < 0.033), and history of multiple sexual partners (P < 0.002).

Research paper thumbnail of Trend of antibiotic resistance in 1316 Shigella strains isolated in Bahrain

Saudi Medical Journal, May 1, 2003

... Trend of antibiotic resistance in 1316 Shigella strains isolated in Bahrain. Jamsheer AE,Bind... more ... Trend of antibiotic resistance in 1316 Shigella strains isolated in Bahrain. Jamsheer AE,Bindayna KM, Al-Balooshi NA, Botta GA. Department of Microbiology, Ministry of Health, Salmaniya Medical Complex, Arabian Gulf University, Manama, Bahrain. ...

Research paper thumbnail of Bacterial Adherence TQ Plastics: A Role in Endoscope-Transmitted Infections

Research paper thumbnail of Gas-liquid chromatography of the gingival fluid as an aid in periodontal diagnosis

Journal of Periodontal Research, 1985

... Acknowledgements The authors wish to acknowledge the valu-able cooperation of the dental stud... more ... Acknowledgements The authors wish to acknowledge the valu-able cooperation of the dental students Maurizio Tonetti and Salvatore Atanasio. We also thank Angela Dagnino and Zito Luisa for typing the manuscript. References ...

Research paper thumbnail of Evaluation of an automated system for identification of anaerobic bacteria

European Journal of Clinical Microbiology & Infectious Diseases, 1994

A fully automated computer-assisted system (ATB system, bioMérieux, France) which uses disposable... more A fully automated computer-assisted system (ATB system, bioMérieux, France) which uses disposable microenzymatic panels was evaluated for its ability to identify 215 strains of anaerobic bacteria (clinical isolates and reference strains). All strains were examined using conventional identification protocols and by gas chromatographic analysis of short-chain fatty acids. Automated reading of Rapid ID32A test kits (bio-Mérieux, France) by the ATB

Research paper thumbnail of The Matter of Mind

Research paper thumbnail of Severity of intestinal disease following Campylobacter jejuni infection correlates with level of TNF-{alpha} production and macrophage apoptosis

The Journal of Immunology, Apr 1, 2010

Research paper thumbnail of Campylobacter jejuni induces diverse kinetics and profiles of cytokine genes in INT-407 cells

Saudi medical journal, 2008

To examine the kinetic ability of embryonic human epithelial INT-407 cells to express messenger r... more To examine the kinetic ability of embryonic human epithelial INT-407 cells to express messenger ribonucleic acid mRNA for various cytokines and chemokines in response to Campylobacter jejuni C. jejuni stimulation. In an experimental single-blind study, cultured embryonic human epithelial INT-407 cells were treated with different concentrations of viable C. jejuni, its sonicated, and filtered supernatant. A modified non-radioactive in situ hybridization using probe cocktails was used to measure mRNA levels for the pro-inflammatory cytokines interleukin IL-1beta, IL-6, interferon-gamma IFN-gamma, tumour necrosis factor TNF-alpha, transforming growth factor TGF-beta1, and IL-8, and the anti-inflammatory cytokines, IL-4 and IL-10. The study was carried out from September 2005 to March 2007 at the Department of Microbiology, Immunology, and Infectious Diseases, College of Medicine, Arabian Gulf University, Bahrain. Viable C. jejuni, sonicated bacteria and filtered supernatant induced hig...

Research paper thumbnail of Malignancy Chronic Hepatitis C Virus Infection After Treatment for Pediatric

Research paper thumbnail of Porcine endogenous retrovirus does not infect human cells using a bioartificial liver model system

Transplantation Proceedings, 2001

Research paper thumbnail of Development of a PCR microplate-capture hybridization method for simple, fast and sensitive detection ofSalmonellaserovars in food

Molecular and Cellular Probes, 1998

The authors have developed an easy and rapid detection and identification system for Salmonella s... more The authors have developed an easy and rapid detection and identification system for Salmonella spp. in food. The gene inv A was selected as the target sequence. Oligonucleotides derived from conserved regions of this gene were able to exclusively prime the amplification of a 389 bp fragment when Salmonella spp. DNA was used as the template. An internal Salmonella spp. specific DNA probe was used for confirmation of the amplified polymerase chain reaction(PCR)product, by Southern blot or microplate-capture hybridization assay. In this fashion the sensitivity of the method was increased 100-fold (4.5 fg total DNA). To validate the method, a total of 75 food samples were tested. The PCR-microplate capture hybridization assay is easy to perform and much faster than traditional detection methods for Salmonella spp. in food. Hybridization in microtitre plates is more readily observed than in Southern blot and is more sensitive than conventional agarose gel electrophoresis.

Research paper thumbnail of Status of Malaria in the Kingdom of Bahrain: a 10-year Review

Journal of Travel Medicine, 2006

Background: Malaria was eradicated in Bahrain about 20 years ago. However, because of a large imm... more 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.

Research paper thumbnail of Induction of α and β chemokines by intestinal epithelial cells stimulated with Campylobacter jejuni

Journal of Infection, 2004

Objectives. To investigate the production of dynamic a and b chemokines represented by interleuki... more Objectives. To investigate the production of dynamic a and b chemokines represented by interleukin-8 (IL-8) as a chemokine and CCL2 (monocyte-chemoattractant protein-1, CCR2 ligand), CCL4 (macrophage-inflammatory protein-1b, CCR5 ligand), CCL3 (macrophage-inflammatory protein-1a, CCR1/5 ligand), (CCL5, regulated upon activation, normal T-cell expressed and secreted (RANTES, CCR5 ligand) as b 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.

Research paper thumbnail of Effect of antibiotic sub inhibitory concentration on cytolethal distending toxin production by

Journal of Infection, 2005

Objectives. To investigate the effect of pre-exposure antibiotics on cytolethal distending toxin ... more 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 C and cdt K 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.

Research paper thumbnail of PCR-RFLP-Detected Human Papilloma Virus Infection in a Group of Senegalese Women Attending an STD Clinic and Identification of a New HPV-68 Subtype

Intervirology, 1999

Cancer of the cervix is the most common malignant tumor among women in Africa and, in particular,... more Cancer of the cervix is the most common malignant tumor among women in Africa and, in particular, Senegal. Studies of the prevalence of human papilloma virus (HPV) infection in Africa have mainly focused on carcinomas. Data on the presence of the virus in women with normal cervical cytology are scarce. In this study, 158 cytologically normal women who had been referred to the ‘Institut Pasteur de Dakar’ (Senegal) for various genital complaints were investigated for the presence of HPV on exfoliated cells by PCR-RFLP. HPV was detected in 13.9% of cases. Oncogenic type HPV 16 was the most common type (40.9%), followed by HPV 53 and HPV 58, both detected in 13.6% of cases. Mixed HPV infections were present in 13.6% of the subjects. Only HPVs belonging to the intermediate-high risk group were detected. These data suggest the need for careful cytological control of patients. A PCR-HPV fragment (GA115) possessing an original RFLP pattern was isolated. After sequencing, it showed a nucleot...

Research paper thumbnail of Invasive capabilities of Campylobacter jejuni strains isolated in Bahrain: Molecular and phenotypic characterization

Acta Microbiologica et Immunologica Hungarica, 2007

The association between putative virulence genes in Campylobacter jejuni clinical isolates, in vi... more The association between putative virulence genes in Campylobacter jejuni clinical isolates, in vitro invasive capability and severity of infection is yet to be clearly described. We have characterized three virulence genes and correlated their presence with the severity of infection and in vitro invasiveness. We studied eight C. jejuni strains isolated from patients whose clinical data were scored to determine severity of infection. Cytolethal distending toxin (cdtB) , invasion associated marker (iam) and Campylobacter invasion antigen (ciaB) genes were detected by PCR and INT407 cells used for invasion assays. Two strains positive for all three genes were the most invasive and isolated from patients with the most severe infection. Four strains positive for two genes and two strains negative for all the three genes were identified. The two cdtB+ ve / ciaB+ ve strains were more invasive than the cdtB+ ve / iam+ ve strains. One of the cdtB− ve / ciaB− ve strains showed invasion levels...

Research paper thumbnail of Resumption of cell division in filaments induced in E. coli by beta-lactam antibiotics possessing affinity for PBP-3

Drugs Under Experimental and Clinical Research, 1984

Research paper thumbnail of ELECTROFOCUSING OF INTEGRAL BACTERIAL MEMBRANE PROTEINS WITH SPECIAL REGARD TO PBPs

Research paper thumbnail of Predominance of CTX-M genotype among extended spectrum beta lactamase isolates in a tertiary hospital in Saudi Arabia

Saudi Medical Journal, Aug 1, 2010

To determine the molecular characterization of extended-spectrum beta-lactamases (ESBL) isolates ... more To determine the molecular characterization of extended-spectrum beta-lactamases (ESBL) isolates from a tertiary center in Saudi Arabia using multiplex polymerase chain reaction (PCR) technique and assess their antibiotic susceptibility pattern. Prospective study conducted at the Saudi Aramco Dhahran Health Center, Dhahran, Saudi Arabia between April-December 2006. Extended-spectrum beta-lactamases phenotype of isolates identified by automated methods was confirmed using E-test. Multiplex PCR for the detection of blaTEM, blaSHV and blaCTX-M was performed. Susceptibility to a panel of antibiotics was determined. One hundred isolates (Escherichia coli [E.coli] n=84; Klebsiella pneumoniae [K. pneumoniae] n=16) were studied and 71% harbored the blaCTX-M gene. For E.coli isolates 43 (51%) harbored CTX-M+TEM combination and 21 (25%) had CTX-M alone. In contrast, only one K. pneumoniae isolate (6.2%) harbored the CTX-M+TEM combination and 3 (18.8%) isolates had CTX-M only. One E.coli and 7 K. pneumoniae isolates were blaSHV positive. The blaCTX-M gene was found predominantly in urinary isolates (n=63/71; 88.7%). The presence of blaCTX-M was significantly higher in isolates from outpatients compared to inpatient (p&amp;amp;lt;0.05). Sensitivity to imipenem was 100% and 78% to nitrofurantoin. Resistance to amoxicillin-sulbactam was significantly higher in blaCTX-M positive isolates (p&amp;amp;lt;0.05). The findings indicate a high-level of blaCTX-M positive ESBL isolates circulating in our setting with the dissemination of these in the community. The trend of multidrug resistance profile associated with carriage of blaCTX-M gene is cause for concern.

Research paper thumbnail of Trends in antibiotic sensitivity pattern and molecular detection of tet(O)-mediated tetracycline resistance in campylobacter jejuni isolates from human and poultry sources

Japanese journal of infectious diseases, 2008

This study was conducted to determine the trends in Campylobacter antibiotic resistance occurring... more This study was conducted to determine the trends in Campylobacter antibiotic resistance occurring in our setting and to assess the differences in the isolates using patterns of plasmid profiles. One hundred Campylobacter jejuni strains of human and poultry origin isolated in 2002-2003 (phase A) and 2005-2006 (phase B) in the Kingdom of Bahrain were evaluated. Susceptibility to erythromycin, ciprofloxacin and tetracycline was determined, and plasmid extraction and polymerase chain reaction detection of the tet(O) gene was carried out. A single erythromycin-resistant isolate was identified, in sharp contrast to the high ciprofloxacin resistance which also showed an increment in phase B. Tetracycline resistance was higher in chicken (80.9%) compared to human (41.3%) isolates (P<0.01). Most isolates harbored two plasmids (23 kb and 35 kb) with significant correlation between tetracycline resistance and plasmid carriage in chicken isolates. The findings show continued effectiveness of...

Research paper thumbnail of Human papillomavirus infection among women attending family planning clinic in Nigeria: prevalence, correlates, and co-infection withChlamydia trachomatis

Journal of Immunoassay and Immunochemistry, 2018

Infection with high-risk genotypes of human papillomavirus (HPV) is considered the main cause of ... more Infection with high-risk genotypes of human papillomavirus (HPV) is considered the main cause of invasive cervical. A number of epidemiologic studies have suggested that HPV and Chlamydia trachomatis (CT) play a synergistic role in the etiology of cervical intraepithelial neoplasia and subsequent cervical cancer. The current study aimed to evaluate the HPV prevalence and the risk factors for co-infection with CT among women attending family planning clinic in Nigeria. Following enrolment, 90 patients were screened for IgG antibodies to virus-like proteins of HPV types 6, 8, 16, and 18. CT seropositivity was tested by enzyme-linked immunosorbent assay for the detection of IgG and IgM antibodies. The prevalence of HPV IgG was 20%. Seropositivity for CT IgM was 77.8% while the IgG was 0%. A total of 10 women (11.1%) were seropositive for both CT IgM and HPV IgG antibodies. Seropositivity for HPV IgG was significantly associated with age at marriage (P < 0.001), current Chlamydia infection (P < 0.011), and number of children (P < 0.025), while seropositivty for HPV IgG and Chlamydia trahomatis IgM was significantly associated with age at coitarche (P < 0.028), number of life sex partners (P < 0.033), and history of multiple sexual partners (P < 0.002).

Research paper thumbnail of Trend of antibiotic resistance in 1316 Shigella strains isolated in Bahrain

Saudi Medical Journal, May 1, 2003

... Trend of antibiotic resistance in 1316 Shigella strains isolated in Bahrain. Jamsheer AE,Bind... more ... Trend of antibiotic resistance in 1316 Shigella strains isolated in Bahrain. Jamsheer AE,Bindayna KM, Al-Balooshi NA, Botta GA. Department of Microbiology, Ministry of Health, Salmaniya Medical Complex, Arabian Gulf University, Manama, Bahrain. ...

Research paper thumbnail of Bacterial Adherence TQ Plastics: A Role in Endoscope-Transmitted Infections

Research paper thumbnail of Gas-liquid chromatography of the gingival fluid as an aid in periodontal diagnosis

Journal of Periodontal Research, 1985

... Acknowledgements The authors wish to acknowledge the valu-able cooperation of the dental stud... more ... Acknowledgements The authors wish to acknowledge the valu-able cooperation of the dental students Maurizio Tonetti and Salvatore Atanasio. We also thank Angela Dagnino and Zito Luisa for typing the manuscript. References ...

Research paper thumbnail of Evaluation of an automated system for identification of anaerobic bacteria

European Journal of Clinical Microbiology & Infectious Diseases, 1994

A fully automated computer-assisted system (ATB system, bioMérieux, France) which uses disposable... more A fully automated computer-assisted system (ATB system, bioMérieux, France) which uses disposable microenzymatic panels was evaluated for its ability to identify 215 strains of anaerobic bacteria (clinical isolates and reference strains). All strains were examined using conventional identification protocols and by gas chromatographic analysis of short-chain fatty acids. Automated reading of Rapid ID32A test kits (bio-Mérieux, France) by the ATB

Research paper thumbnail of The Matter of Mind

Research paper thumbnail of Severity of intestinal disease following Campylobacter jejuni infection correlates with level of TNF-{alpha} production and macrophage apoptosis

The Journal of Immunology, Apr 1, 2010

Research paper thumbnail of Campylobacter jejuni induces diverse kinetics and profiles of cytokine genes in INT-407 cells

Saudi medical journal, 2008

To examine the kinetic ability of embryonic human epithelial INT-407 cells to express messenger r... more To examine the kinetic ability of embryonic human epithelial INT-407 cells to express messenger ribonucleic acid mRNA for various cytokines and chemokines in response to Campylobacter jejuni C. jejuni stimulation. In an experimental single-blind study, cultured embryonic human epithelial INT-407 cells were treated with different concentrations of viable C. jejuni, its sonicated, and filtered supernatant. A modified non-radioactive in situ hybridization using probe cocktails was used to measure mRNA levels for the pro-inflammatory cytokines interleukin IL-1beta, IL-6, interferon-gamma IFN-gamma, tumour necrosis factor TNF-alpha, transforming growth factor TGF-beta1, and IL-8, and the anti-inflammatory cytokines, IL-4 and IL-10. The study was carried out from September 2005 to March 2007 at the Department of Microbiology, Immunology, and Infectious Diseases, College of Medicine, Arabian Gulf University, Bahrain. Viable C. jejuni, sonicated bacteria and filtered supernatant induced hig...

Research paper thumbnail of Malignancy Chronic Hepatitis C Virus Infection After Treatment for Pediatric

Research paper thumbnail of Porcine endogenous retrovirus does not infect human cells using a bioartificial liver model system

Transplantation Proceedings, 2001

Research paper thumbnail of Development of a PCR microplate-capture hybridization method for simple, fast and sensitive detection ofSalmonellaserovars in food

Molecular and Cellular Probes, 1998

The authors have developed an easy and rapid detection and identification system for Salmonella s... more The authors have developed an easy and rapid detection and identification system for Salmonella spp. in food. The gene inv A was selected as the target sequence. Oligonucleotides derived from conserved regions of this gene were able to exclusively prime the amplification of a 389 bp fragment when Salmonella spp. DNA was used as the template. An internal Salmonella spp. specific DNA probe was used for confirmation of the amplified polymerase chain reaction(PCR)product, by Southern blot or microplate-capture hybridization assay. In this fashion the sensitivity of the method was increased 100-fold (4.5 fg total DNA). To validate the method, a total of 75 food samples were tested. The PCR-microplate capture hybridization assay is easy to perform and much faster than traditional detection methods for Salmonella spp. in food. Hybridization in microtitre plates is more readily observed than in Southern blot and is more sensitive than conventional agarose gel electrophoresis.

Research paper thumbnail of Status of Malaria in the Kingdom of Bahrain: a 10-year Review

Journal of Travel Medicine, 2006

Background: Malaria was eradicated in Bahrain about 20 years ago. However, because of a large imm... more 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.

Research paper thumbnail of Induction of α and β chemokines by intestinal epithelial cells stimulated with Campylobacter jejuni

Journal of Infection, 2004

Objectives. To investigate the production of dynamic a and b chemokines represented by interleuki... more Objectives. To investigate the production of dynamic a and b chemokines represented by interleukin-8 (IL-8) as a chemokine and CCL2 (monocyte-chemoattractant protein-1, CCR2 ligand), CCL4 (macrophage-inflammatory protein-1b, CCR5 ligand), CCL3 (macrophage-inflammatory protein-1a, CCR1/5 ligand), (CCL5, regulated upon activation, normal T-cell expressed and secreted (RANTES, CCR5 ligand) as b 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.

Research paper thumbnail of Effect of antibiotic sub inhibitory concentration on cytolethal distending toxin production by

Journal of Infection, 2005

Objectives. To investigate the effect of pre-exposure antibiotics on cytolethal distending toxin ... more 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 C and cdt K 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.

Research paper thumbnail of PCR-RFLP-Detected Human Papilloma Virus Infection in a Group of Senegalese Women Attending an STD Clinic and Identification of a New HPV-68 Subtype

Intervirology, 1999

Cancer of the cervix is the most common malignant tumor among women in Africa and, in particular,... more Cancer of the cervix is the most common malignant tumor among women in Africa and, in particular, Senegal. Studies of the prevalence of human papilloma virus (HPV) infection in Africa have mainly focused on carcinomas. Data on the presence of the virus in women with normal cervical cytology are scarce. In this study, 158 cytologically normal women who had been referred to the ‘Institut Pasteur de Dakar’ (Senegal) for various genital complaints were investigated for the presence of HPV on exfoliated cells by PCR-RFLP. HPV was detected in 13.9% of cases. Oncogenic type HPV 16 was the most common type (40.9%), followed by HPV 53 and HPV 58, both detected in 13.6% of cases. Mixed HPV infections were present in 13.6% of the subjects. Only HPVs belonging to the intermediate-high risk group were detected. These data suggest the need for careful cytological control of patients. A PCR-HPV fragment (GA115) possessing an original RFLP pattern was isolated. After sequencing, it showed a nucleot...

Research paper thumbnail of Invasive capabilities of Campylobacter jejuni strains isolated in Bahrain: Molecular and phenotypic characterization

Acta Microbiologica et Immunologica Hungarica, 2007

The association between putative virulence genes in Campylobacter jejuni clinical isolates, in vi... more The association between putative virulence genes in Campylobacter jejuni clinical isolates, in vitro invasive capability and severity of infection is yet to be clearly described. We have characterized three virulence genes and correlated their presence with the severity of infection and in vitro invasiveness. We studied eight C. jejuni strains isolated from patients whose clinical data were scored to determine severity of infection. Cytolethal distending toxin (cdtB) , invasion associated marker (iam) and Campylobacter invasion antigen (ciaB) genes were detected by PCR and INT407 cells used for invasion assays. Two strains positive for all three genes were the most invasive and isolated from patients with the most severe infection. Four strains positive for two genes and two strains negative for all the three genes were identified. The two cdtB+ ve / ciaB+ ve strains were more invasive than the cdtB+ ve / iam+ ve strains. One of the cdtB− ve / ciaB− ve strains showed invasion levels...

Research paper thumbnail of Resumption of cell division in filaments induced in E. coli by beta-lactam antibiotics possessing affinity for PBP-3

Drugs Under Experimental and Clinical Research, 1984

Research paper thumbnail of ELECTROFOCUSING OF INTEGRAL BACTERIAL MEMBRANE PROTEINS WITH SPECIAL REGARD TO PBPs

Research paper thumbnail of Predominance of CTX-M genotype among extended spectrum beta lactamase isolates in a tertiary hospital in Saudi Arabia

Saudi Medical Journal, Aug 1, 2010

To determine the molecular characterization of extended-spectrum beta-lactamases (ESBL) isolates ... more To determine the molecular characterization of extended-spectrum beta-lactamases (ESBL) isolates from a tertiary center in Saudi Arabia using multiplex polymerase chain reaction (PCR) technique and assess their antibiotic susceptibility pattern. Prospective study conducted at the Saudi Aramco Dhahran Health Center, Dhahran, Saudi Arabia between April-December 2006. Extended-spectrum beta-lactamases phenotype of isolates identified by automated methods was confirmed using E-test. Multiplex PCR for the detection of blaTEM, blaSHV and blaCTX-M was performed. Susceptibility to a panel of antibiotics was determined. One hundred isolates (Escherichia coli [E.coli] n=84; Klebsiella pneumoniae [K. pneumoniae] n=16) were studied and 71% harbored the blaCTX-M gene. For E.coli isolates 43 (51%) harbored CTX-M+TEM combination and 21 (25%) had CTX-M alone. In contrast, only one K. pneumoniae isolate (6.2%) harbored the CTX-M+TEM combination and 3 (18.8%) isolates had CTX-M only. One E.coli and 7 K. pneumoniae isolates were blaSHV positive. The blaCTX-M gene was found predominantly in urinary isolates (n=63/71; 88.7%). The presence of blaCTX-M was significantly higher in isolates from outpatients compared to inpatient (p&amp;amp;lt;0.05). Sensitivity to imipenem was 100% and 78% to nitrofurantoin. Resistance to amoxicillin-sulbactam was significantly higher in blaCTX-M positive isolates (p&amp;amp;lt;0.05). The findings indicate a high-level of blaCTX-M positive ESBL isolates circulating in our setting with the dissemination of these in the community. The trend of multidrug resistance profile associated with carriage of blaCTX-M gene is cause for concern.

Research paper thumbnail of Trends in antibiotic sensitivity pattern and molecular detection of tet(O)-mediated tetracycline resistance in campylobacter jejuni isolates from human and poultry sources

Japanese journal of infectious diseases, 2008

This study was conducted to determine the trends in Campylobacter antibiotic resistance occurring... more This study was conducted to determine the trends in Campylobacter antibiotic resistance occurring in our setting and to assess the differences in the isolates using patterns of plasmid profiles. One hundred Campylobacter jejuni strains of human and poultry origin isolated in 2002-2003 (phase A) and 2005-2006 (phase B) in the Kingdom of Bahrain were evaluated. Susceptibility to erythromycin, ciprofloxacin and tetracycline was determined, and plasmid extraction and polymerase chain reaction detection of the tet(O) gene was carried out. A single erythromycin-resistant isolate was identified, in sharp contrast to the high ciprofloxacin resistance which also showed an increment in phase B. Tetracycline resistance was higher in chicken (80.9%) compared to human (41.3%) isolates (P<0.01). Most isolates harbored two plasmids (23 kb and 35 kb) with significant correlation between tetracycline resistance and plasmid carriage in chicken isolates. The findings show continued effectiveness of...