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Molecular study of Helicobacter pylori virulence genes CagA, Hpa and BabA2 in Egyptian patients

M.E.S. Zaki, M.A. Rizk, A.O. Bakr, Mahmoud Mahmoud, M.A. Ali, A Shehta

 

Abstract

Objective: The objective of this study was to detect virulence genes of Helicobacter pylori (H.pylori) cagA, babA2 and hpa in gastric biopsies from patients with different stages of gastritis by polymerase chain reaction to correlate the presence of genes with the severity of the diseases.

Method: A total of 80 non repetitive gastric biopsies from antrum of the stomach were obtained from the patients and subjected to study for histological examination, unease activity, culture for H.pylori, and polymerase chain reaction studies of virulence genes cagA, babA2 and hpa.

Results: The most frequent detected gene by PCR was hpa (66.7%) and followed by cagA and babA2 (61.6%) for each. There was significant association between the three genes (P=0.0001). The study of the association between the virulence gene of H.pylori and different clinical symptoms revealed significant association of dyspepsia with cagA(P=0.001) babA2 and hpa (P=0.0001), regurgitation with cagA and babA2( P=0.002),vomiting with cagA and babA2 (P=0.01, P=0.002, respectively) and nausea with cagA and babA2 (P=0.0001, P=0.03, respectively). The virulence genes were detected in gastric ulcer. The degree of inflammation in histopathological examination was also statistically significant associated with the presence of virulences genes cagA (P=0.01), babA2 (p=0.0001) and hpa (P=0.0001)

The present study highlights the presence of virulence genes in H.pylori associated with gastric ulcer. The genes cagA, babA2 and hpa are prevalent among the strains affecting the patients. Moreover, these genes are associated with marked clinical and pathological severity. The genes are significantly associated with each other. Further studies are recommended to validate these findings.

Keywords: Gastritis, Genotypes, H.pylori, cagA, babA2, hpa, PCR

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Molecular study of Helicobacter pylori virulence genes CagA, Hpa and BabA2 in Egyptian patients

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Molecular characterization of extended spectrum beta-lactamase among clinical multidrug resistant Escherichia Coli in two hospitals of Niamey, Niger

A. M. Fody, T. S Bagré, A. K. Traoré, A Yacouba, R. Dembelé, L. Boubou, A. Inoussa, R. Sidikou, A. S. Traoré, A. Gassama-Sow, N. Barro

 

Abstract

Objective: The aim of this study was to identify the multiple ESBL genes in Multidrug-resistant (MDR) Escherichia coli isolated in various biological samples in two hospitals of Niamey.
Methodology: A total of 195 multidrug-resistant Escherichia coli were included in the study. These isolates were tested using polymerase chain reaction (PCR) for detection of the presence of bla CTX-M, bla TEM, bla SHV and bla OXA-1 beta-lactamase genes.
Results: A total of 27.7% of Escherichia coli isolates were ESBL producing strains. Globaly, the bla TEM gene was the most prevalent (70.3%) followed by bla CTX-M (43.1%), bla OXA-1 (31.8%) and bla SHV (4.1%) genes. The four genes type of ESBL were founded simultaneously only in stool samples. Furthermore, none bla SHV gene was found in other samples type.
Conclusion: This study showed the presence of various ESBL genes among clinical MDR Escherichia coli. That is why a rational use of antibiotic and appropriate methods of screening ESBL genes in routine laboratories in Niger is needed to control the ESBL genes dissemination.

Keywords: MDR ,Escherichia coli, ESBL, bla genes, PCR, Niamey, Niger.

 

Caracterisation moleculaire des betalactamases a spectre etendu chez les souches de Escherichia coli multi resistantes dans deux hopitaux de Niamey, au Niger

Objectifs: Le but de cette étude était d’identifier les multiples gènes de BLSE chez les souches de Escherichia coli multi résistantes isolées de différents types d’échantillons biologiques dans deux hôpitaux de Niamey.
Méthodologie : Un total de 195 Escherichia coli multi résistants a été inclus dans l’étude. Ces isolats ont été testés par la réaction de polymérase en chaîne (PCR) pour détecter la présence des gènes bla CTX-M, bla TEM, bla SHV et bla OXA-1.
Résultats : Au total, 27,7% des isolats de Escherichia coli multi-résistants étaient des souches productrices de BLSE. Globalement le gène blaTEM (70,3%) était le plus détecté suivi des autres gènes bla CTX-M (43,1%), bla OXA-1 (31,8%) et bla SHV (4,1%). Notons que seul dans les échantillons de selles quatre types de gènes de BLSE ont été trouvés simultanément. Par ailleurs notons qu’aucun gène de type bla SHV n’a été trouvé dans les autres types d’échantillons.
Conclusion : Cette étude avait montré la présence de divers gènes de BLSE chez les souches cliniques de Escherichia coli. C’est pourquoi une utilisation rationnelle des antibiotiques et des méthodes appropriées de dépistage des gènes de BLSE dans les laboratoires sont nécessaires afin de contrôler la diffusion des gènes de BLSE.

Mots clés : Escherichia coli multi résistantes, BLSE, gènes bla, PCR, Niamey, Niger

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Molecular characterization of extended spectrum beta-lactamase among clinical multidrug resistant Escherichia Coli in two hospitals of Niamey, Niger

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Molecular detection of salmonella species from selected vegetables sold in a north-central Nigerian setting

D.S. Adeniyi, T.M. Akindigh, F.N. Aniweta, H.J. Zumbes, A.J. Anejo-okopi

 

Abstract

It is vital to study and understand the genetic basis to the virulence of different Salmonella strains in other to fully grasp the facts behind the unique capabilities of these pathogenic agents to causing diseases in both humans and animals. In this study, the conventional microbiological culture methods were used to isolate pure Salmonella strains from 120 vegetable samples of five different types; which were all obtained at seven different popular markets in the Jos Metropolis of North Central Nigeria. 25 (20.8%) pure isolates were obtained from 120 samples after initial culture and sub-cultures; with 24 (20%) of the pure isolates testing positive as being pathogenic after biochemical analysis. From the 25 pure isolates, the same 24 which tested positive for biochemical tests were also successfully amplified by PCR technique with the SalmonellainvA virulence gene. The result shows that 96% of the pure isolates were positive for the Salmonella invA gene. The PCR product which was very specific is a 250bp fragment of DNA which was visualized in 1.5% agarose gel. This finding shows that virulent Salmonella strains pose a major health hazard and public health concern to the affected population. Our study shows that there is a high prevalence rate of virulent Salmonella strains in North-Central Nigeria. It is thus concluded that although both the conventional culture and biochemical methods of isolating Salmonella species are most useful for obtaining pure isolates and identifying pathogenic strains, however, the PCR technique remains the most specific and sensitive; especially when the rapid identification and detection of virulent strains of Salmonella species are of utmost importance.

Keywords: Virulence, invA gene, PCR, North Central Nigeria

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Molecular detection of salmonella species from selected vegetables sold in a north-central Nigerian setting

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Molecular Identification of Methicillin-Resistant Staphylococcus aureus in Benin-City Nigeria

O Obasuyi

 

Abstract

We use the molecular techniques of PCR and PFGE to identify MRSA from clinical isolates of Staphylococcus aureus causing infections among hospitalized patients in Benin-City, Nigeria. A total of 36 isolates were obtained from the University of Benin Teaching Hospital between July-September, 2007. The MRSA strains were selected according to their phenotypic characteristics (antibiotic resistant profiles), susceptibility to oxacillin by E-test, and detection of β-lactamase. This was verified by a latex agglutination test for PBP2a production combined with PCR for mecA gene carriage. Four isolates representing 11% were confirmed as MRSA according to the molecular techniques used with two PFGE types (H and L) and one agr type (1). Multi resistance to the various antibiotics used was observed in one of the clones. The isolation of MRSA in health institution indicates that adequate steps in limiting spread are urgently needed. Also, for the first time two MRSA clones according to the PFGE classifications have been identified in Nigeria.

Keywords: methicillin-resistant Staphylococcus aureus, MRSA, PFGE, PCR, molecular techniques.

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Molecular Identification of Methicillin-Resistant Staphylococcus aureus in Benin-City Nigeria