ABSTRACT
<p><b>OBJECTIVE</b>To investigate and compare the resistance and sensitivity of Salmonella typhi samples to commonly used antibiotics in three major divisions of Bangladesh and to evaluate the gradually developing resistance pattern.</p><p><b>METHODS</b>The antibiotic susceptibility of 70 clinical isolates collected from blood, sputum, urine and pus samples were identified by specific antisera and with standard biochemical tests. The patients were divided into 5 age groups. Susceptibility and resistance was also tested by Kirby-Bauer disc diffusion method using 12 regularly used antibiotics.</p><p><b>RESULTS</b>Antibiotic susceptibility test demonstrated that 64.28% isolates of Salmonella typhi were multidrug resistant. Present study suggests that the clinical samples were mostly resistant against nalidixic acid with all age groups and in all three divisions with similar resistance pattern. Resistance is more common among adult people (30-40 years) and children (0-10 years). Salmonella typhi was mostly sensitive against gentamycin, chloramphenicol and ciprofloxacin.</p><p><b>CONCLUSIONS</b>Although the population density of Dhaka region is markedly higher than Rajshahi and Chittagong regions, no significant difference in resistance pattern was found. The rate of multidrug resistance is a matter of concern. Physicians should reconsider before prescribing nalidixic acid and cefixime. Further molecular study is needed to reveal the genomic and proteomic basis of resistance.</p>
ABSTRACT
Chitinases (designated as SPCs) were isolated from „Shilbilati‟ potatoes, a potato prototype cultivated in Bangladesh by affinity chromatography on a chitin column. SPCs agglutinated rat erythrocytes at the minimum concentration of 7 μg/mL and showed toxicity against brine shrimp nauplii with the LC50 value of 20 μg/mL. The chitinases also agglutinated seven bacterial strains among the twelve as studied. Pseudomonas aeruginosa, Bacillus subtilis and Salmonella typhi were the most sensitive towards the SPCs and were agglutinated at 1.2, 2.5 and 5.0 μg/mL protein concentrations respectively. Antibacterial tests demonstrated that SPCs showed inhibitory activity against the pathogenic bacteria Staphylococcus aureus, Bacillus subtilis and Salmonella typhi. Antifungal activity was investigated by the disc diffusion method. Five fungal species (Candida albicans, Aspergillus niger, Fusarium vasinfectum, Aspergillus fumigatus and Aspergillus flavus) and two fungal genus (Penicillium and Mucor sp.) were examined in the assay. SPCs showed antifungal activity against Candida albicans, Fusarium vasinfectum and Penicillium sp.