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S Q Akhtar

Publications and source records attributed to S Q Akhtar.

7 recordsLinked to original sources
PubMed1991

Study on the pathogenicity of Campylobacter jejuni by modifying the medium.

Campylobacter jejuni has been documented as one of the major aetiological agents of diarrhoeal illness all over the world. Studies revealed its pathogenicity by different assay methods, but none could be strongly recommended as a tool for differentiating toxigenic strains of C. jejuni. This study was an attempt to demonstrate better its pathogenicity by media modification. Fifteen isolates of C. jejuni recovered from diarrhoeal patients at the International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR,B), Dhaka Hospital were included in this study. The standard medium for C. jejuni was modified by the incorporation of FeCl3 at different concentrations. The pathogenicity of the test isolates were studied by rabbit ileal loop assay; Chinese hamster ovary (CHO), human epithelial cervical carcinoma (HeLa); Y-1 adrenal cell lines and suckling mouse assay. Sonicated extracts of the test organisms, grown with FeCl3 supplement, were also assayed. An enhanced growth of C. jejuni was obtained with the increasing concentration of FeCl3 supplementation in the medium. Only five isolates of C. jejuni produced cytotoxic effect on HeLa cell monolayer. Other cell lines were not affected by the test specimens or sonicates. Rabbit ileal loop assay did not reveal any fluid accumulation but on dissection, the test loops were found highly haemorrhagic. No heat-stable (ST) toxin could be detected. Cell-free culture supernatant of patients' isolates of C. jejuni had an effect on HeLa cell monolayer. Sonicated extracts of patients' extracts had a greater effect on HeLa cell monolayer. Pathogenic strains of C. jejuni might be distinguished on HeLa cell monolayer using its sonicated extracts.

Animals↗
PubMed1989

Effect of Campylobacter jejuni extracts and culture supernatants on cell culture.

This study reports the effect of culture supernatants and extracts of Campylobacter jejuni isolated in Bangladesh from patients with gastroenteritis, asymptomatic carriers, poultry, and animals on tissue culture system. Isolates from patients produced morphologic changes on HeLa, Vero and Y1 adrenal cell lines. Incorporation of polymyxin B in the culture medium enhanced the effect on cell lines significantly and sonicated extracts of the organisms had an even more significant effect. Almost all sonicated extracts of patients' isolates had effect on HeLa cells. Animal isolates, using identical conditions, had much less effect on cell lines whereas isolates from asymptomatic carriers produced almost no effect. This toxicity of the patients' isolates might indicate some relation to pathogenic strains.

Adrenal Glands↗
PubMed1988

Antimicrobial sensitivity and plasmid-mediated tetracycline resistance in Campylobacter jejuni isolated in Bangladesh.

The antimicrobial sensitivity of Campylobacter jejuni isolated in Bangladesh from patients with diarrhoea, asymptomatic carriers and domestic animals was performed. All isolates were sensitive to erythromycin, gentamicin, furazolidone and kanamycin. Seven percent isolates were resistant to tetracycline, 8% to nalidixic acid, 37% to ampicillin and 100% to sulfamethoxazole-trimethoprim and cephalothin. Tetracycline resistance was observed to be plasmid mediated. No plasmid band(s) coding for ampicillin, sulfamethoxazole-trimethoprim or cephalothin resistance were observed, possibly indicating chromosomally located resistance. No significant differences in the susceptibility patterns of C. jejuni isolated from the different sources was observed. However, 10 patients' isolates showed low molecular weight (2-3, 7 Mdaltons) plasmid band(s) which were completely absent in isolates from asymptomatic carriers and animals.

Anti-Bacterial Agents↗
PubMed1988

Characterization of Campylobacter strains isolated in Bangladesh from different sources.

Campylobacters have been isolated in Bangladesh from patients with gastroenteritis, from healthy individuals and animals. A total of 180 Campylobacter isolates, 100 from patients with gastroenteritis reporting to International Centre for Diarrhoeal Disease Research, Bangladesh hospitals, 50 from asymptomatic carriers and the other 30 from domestic animals of the index cases have been characterized following standard procedures available. All isolates tested have been confirmed as Campylobacter jejuni. Irrespective of their source of isolation, Campylobacter isolates showed identical biochemical behaviours. All isolates showed thermophilic characteristics of jejuni/coli group. None of the isolates grew at 25 degrees C. Uniform sensitivity to nalidixic acid, metronidazole, 2, 3, 5-triphenyltetrazolium chloride, resistance to cephalothin was observed; H2S production in all isolates by different methods was confirmed. All isolates from different sources confirmed to be C. jejuni; none of the isolates, even from the animal source could be characterized as C. coli.

Animals↗
PubMed1987

Isolation of Clostridium difficile from diarrhoea patients in Bangladesh.

An attempt was made to detect Clostridium difficile and its toxin from the stools of 20 patients with antibiotic-associated diarrhoea (AAD), 35 with colitis, six with chronic diarrhoea and 300 with watery diarrhoea. Two toxigenic and three non-toxigenic strains were isolated from patients associated with antimicrobial therapy. All 300 stools from watery diarrhoea patients, not associated with antibiotics, were negative for Cl. difficile and its toxin. We conclude that Cl. difficile might be a cause of AAD in Bangladesh.

Bacterial Proteins↗
PubMed1986

Application of Biken test (modified Elek test) for sampling of heat-stable enterotoxin of Escherichia coli isolated in Bangladesh.

The usefulness of Biken Agar 2 as a source of heat-stable toxin for the suckling mouse assay was examined. Escherichia coli (E. coli) strains isolated in Bangladesh from patients with gastroenteritis found to produce heat-stable toxin (n = 152), both heat-stable and heat-labile toxin (n = 60) and not to produce heat-stable or heat-labile toxin (n = 25) by standard suckling mice assay using broth culture were tested. Sampling from Biken Agar 2 gave comparable results to those obtained using standard broth cultures. This is the first field survey of evaluation of the Biken test for sampling heat-stable toxin of E. coli. The result further clarifies the applicability of the Biken test for sampling heat-stable toxin, and the usefulness of the Biken test for detections of heat-labile and heat-stable toxin produced by E. coli.

Animals↗