Shamsun Nahar - Academia.edu (original) (raw)

Papers by Shamsun Nahar

Clinical Infectious Diseases, 2001

Although ciprofloxacin is one of the recommended drugs of choice for the treatment of gonorrhea, ... more Although ciprofloxacin is one of the recommended drugs of choice for the treatment of gonorrhea, in vitro resistance to this drug has been observed in surveillance studies and case reports from many parts of the world, including Bangladesh. However, to our knowledge, there have been no prospective studies of the correlation between in vitro response to the drug and treatment outcome. Therefore, a prospective study of 217 female sex workers in Dhaka, Bangladesh, was conducted to examine the correlation between the in vitro response of Neisseria gonorrhoeae and the outcome of ciprofloxacin treatment. Overall, 37.8% of the gonococcal isolates recovered from female sex workers were resistant to ciprofloxacin, and there was a good correlation between in vitro resistance and treatment failure. These findings suggest that in vitro resistance to ciprofloxacin is predictive of clinical treatment failure in patients with gonorrhea.

International Journal of Advanced Renewable Energy Researches, Jun 30, 2012

 Abstract-Pineapple is perishable in fresh form and shelf life is limited, which leads subsequen... more  Abstract-Pineapple is perishable in fresh form and shelf life is limited, which leads subsequent post harvest loss every year in Bangladesh. The current study was conducted to investigate the effects of gamma irradiated and un-irradiated chitosan coating on different quality parameters (ripening, biochemical and organoleptic) and shelf life extension of pineapple over a storage period of 18 days at ambient environment (30 ± 1°C /75 ± 5% RH). Preserved fruits maintained their eating quality during whole storage period without visual fungal growth. Dry matter content, total soluble solids, titratable acidity, reducing sugar, moisture content and ascorbic acid were also observed. All of the results were analyzed statistically and found to be significantly different. The overall results showed the superiority of irradiated chitosan (15 kGy) in extending the shelf life of pineapple and potentiality to be used on fresh produce to maintain quality and extending shelf life.

Helicobacter, Jan 31, 2015

Helicobacter pylori is a highly genetically diverse bacterial species, which can persist in the g... more Helicobacter pylori is a highly genetically diverse bacterial species, which can persist in the gastric environment for decades. Recent studies have shown that single infections predominate in developed countries, whereas mixed infections are more prevalent in developing countries. Mixed infections of this bacterium may be important for adaptation to the hostile gastric environment and may facilitate dyspeptic symptoms. To calculate the prevalence of mixed infections in symptomatic and asymptomatic subjects, 2010 H. pylori isolates collected from 83 symptomatic and 91 asymptomatic subjects from Dhaka, Bangladesh, were analyzed by (i) random amplified polymorphic DNA fingerprinting (RAPD) and (ii) multiplex PCR amplification for cagA and vacA virulence gene alleles. The overall prevalence of mixed H. pylori infection was 60.15% (77/128), indicating substantial co-colonization in this population. We additionally found that symptomatic subjects (53%) had a significantly higher rate of ...

Journal of medical microbiology, 2000

Recent case-control studies in Bangladesh showed a high prevalence of enteropathogenic Escherichi... more Recent case-control studies in Bangladesh showed a high prevalence of enteropathogenic Escherichia coli (EPEC) strains (identified by DNA probes for virulence genes) associated with childhood diarrhoea. However, the clonal status of these strains is not known. A total of 94 EPEC isolates from 80 children with diarrhoea and 14 healthy matched controls isolated during 1991-1992 and 1993-1994 was characterised by serogrouping, enterobacterial repetitive intergenic consensus sequence PCR, and by a biochemical fingerprinting method (the phene plate or PhP system). Twelve O serogroups were found with O114 (n = 19) and O127 (n = 23) being the dominant serogroups. Most strains of O114 belonged to the same PhP/PCR types. Strains of O127 contained 16 that produced cytolethal distending toxin (CDT) and seven that did not; both were found among patients as well as controls. Results of PCR and PhP typing showed that CDT-positive strains belonged to the same clonal group and were related to one o...

Journal of clinical microbiology, 1999

Commercial sex workers (CSWs) serve as the most important reservoir of sexually transmitted disea... more Commercial sex workers (CSWs) serve as the most important reservoir of sexually transmitted diseases (STD), including gonorrhea. Periodic monitoring of the antimicrobial susceptibility profile of Neisseria gonorrhoeae in a high-risk population provides essential clues regarding the rapidly changing pattern of antimicrobial susceptibilities. A study concerning the prevalence of gonococcal infection among CSWs was conducted in Bangladesh. The isolates were examined with regards to their antimicrobial susceptibility to, and the MICs of, penicillin, tetracycline, ciprofloxacin, cefuroxime, ceftriaxone, and spectinomycin by disk diffusion and agar dilution methods. The total plasmid profile of the isolates was also analyzed. Of the 224 CSWs, 94 (42%) were culture positive for N. gonorrhoeae. There was a good correlation between the results of the disk diffusion and agar dilution methods. Some 66% of the isolates were resistant to penicillin, and 34% were moderately susceptible to penicil...

Journal of clinical microbiology, 1997

In a previous study using pure bacterial cultures in a PCR assay, a primer pair corresponding to ... more In a previous study using pure bacterial cultures in a PCR assay, a primer pair corresponding to a unique chromosomal region of Vibrio cholerae O139 Bengal generated an amplicon from only V. cholerae O139 Bengal. PCR with the same primer pair was used to screen 180 diarrheal stool specimens. All the 67 V. cholerae O139 culture-positive stool specimens were positive by PCR, and the remaining specimens, which contained either other recognized enteric pathogens or no pathogens, were all negative by PCR.

Journal of clinical microbiology, 1996

From the stool of a Vibrio cholerae O139 Bengal-infected patient, a phage that specifically lysed... more From the stool of a Vibrio cholerae O139 Bengal-infected patient, a phage that specifically lysed capsulated V. cholerae O139 strains only was isolated. The phage is useful for the confirmatory diagnosis of V. cholerae O139 infection and for the differentiation of variants that lack the capsule.

Journal of clinical microbiology, 2000

An etiological study of sexually transmitted infections (STIs) was conducted among female sex wor... more An etiological study of sexually transmitted infections (STIs) was conducted among female sex workers (FSWs) in Dhaka, Bangladesh. Endocervical swab and blood samples from 269 street-based FSWs were examined for Neisseria gonorrhoeae, Chlamydia trachomatis, and Trichomonas vaginalis as well as for antibodies to Treponema pallidum and herpes simplex virus 2 (HSV-2). Sociodemographic data and data regarding behavior were also collected. A total of 226 of the 269 FSWs (84%) were positive for the STI pathogens studied. Among the 269 FSWs, 35.5% were positive for N. gonorrhoeae, 25% were positive for C. trachomatis, 45.5% were positive for T. vaginalis, 32.6% were seropositive for T. pallidum, 62.5% were seropositive for HSV-2, and 51% had infections with two or more pathogens.

Journal of medical microbiology, 2002

Recent studies have shown that Providencia alcalifaciens is a diarrhoeal pathogen. It may cause d... more Recent studies have shown that Providencia alcalifaciens is a diarrhoeal pathogen. It may cause diarrhoea by an invasive mechanism, as it invades cultured mammalian cells in vitro and intestinal epithelial cells of experimentally inoculated rabbits in vivo. To locate the gene(s) involved in invasion, TnphoA mutants of a diarrhoeal isolate of P. alcalifaciens were generated. Compared with the parent strain, these mutants exhibited negligible invasion and actin condensation in HEp-2 cells. TnphoA insertion was located in fragments of 4.9 kb and 11.1 kb of the bacterial chromosome by Southern blot. These mutants did not secrete a 28-kDa protein, which may be involved in invasion. It should be possible now to study the gene(s) involved in invasion of P. alcalifaciens with these mutants. This investigation is another example of the usefulness of TnphoA mutagenesis in the study of bacterial virulence genes.

Bangladesh Journal of Medical Microbiology, 2009

Helicobacter pylori infection occurs worldwide with a high prevalence in developing countries. Vi... more Helicobacter pylori infection occurs worldwide with a high prevalence in developing countries. Virulence of H. pylori strains varies in different geographic regions. The aim of this study was to see H. pylori infection and its strain types in adult dyspeptic patients in Bangladesh and to analyze association of H. pylori strain types with clinical disease and severity of histological gastritis. Ninety consecutive adult dyspeptic patients undergoing diagnostic endoscopy were tested for H. pylori infection by culture, rapid urease test (RUT), histology and anti H. pylori IgG ELISA (Enzyme linked immunosorbent assay). H. pylori strain types were determined by Western Blot analysis. Association of strain types with clinical gastro-duodenal diseases and grades of histological gastritis were analyzed by χ 2 test. Among the selected patients, 53 (58.9%) were culture positive, 48 (53.3%) were RUT positive, 31 (34.4%) were histology positive and 82 (91.1%) were anti-H. pylori IgG ELISA positive. By Western Blot analysis of the 90 sera samples, 48 (53.3%) showed antibodies to Type I strain of H. pylori, 21 (23.3%) Intermediate strain and 3 (3.3%) Type II strain. Endoscopically, 20 (22.2%) patients were found normal, 27 (30.0%) had gastritis, 9 (10.0%) had duodenitis, 28 (31.1%) had peptic ulcer disease, 4 (4.4%) had gastric carcinoma, and 2 (2.2%) had reflux esophagitis. Histologically, 34.4% had H. pylori, 44.4% had polymorhonuclear neutrophil (PMN), 100% had mononuclear cell (MNC) infiltration of different grades, 1.1% had atrophic gastritis and 2.2% had intestinal metaplasia of moderate grade. H. pylori strain types was not associated with clinical gastro-duodenal diseases or grades of PMN or MNC infiltration (p > 0.05) in these patients.

2005. A total number of 1107 cancer patients were included, of them 72% were smoker, 500 were mal... more 2005. A total number of 1107 cancer patients were included, of them 72% were smoker, 500 were male and 607 were female. So the male to female ratio was 1: 1.21. Highest incidence of malignancy was observed in the age of 46 to 60. Top five malignancies in female like-Breast, Cervix, Ovary, Gall Bladder, Stomach. Top five malignancies in male like-Lung, Stomach, Liver, Lymphoma, and Colon. (Bang. Onc. J. 2009; 4 (2) : 59-62)

Bangladesh Medical Journal, 2009

Cigarette smoking is an intractable public health problem that poses threat to the health of the ... more Cigarette smoking is an intractable public health problem that poses threat to the health of the entire population. Smoking is considered as the single largest risk factor for a variety of malignancies, including lung cancer. The prevalence of smoking is gradually increasing among the students in Bangladesh. Considering this view, this cross sectional study was conducted in a selected higher secondary college of Moulvibazar district under Sylhet division. The objectives of the study were to determine the proportion of current smokers and its determinants among the college students. A total of 719 students were interviewed using self administered questionnaire. The mean age (SD) of the students was 17.1(SD 1.5) years ranging from 15 to 22 years. Majority of the respondents were male (57.4%) and 42.6% were female with male-female ratio of 1.3:1. Out of 719 students, 22% were current smokers and the rest 78% were non smokers. Half of the students reportedly mentioned that they started smoking due to peer pressure followed by curiosity (34%), to avoid anxiety and tension (28%), feeling of maturity (14%, symbol of manliness (9%) etc. The most frequent form of smoking was cigarette(56%) followed by Bidi (37%), Hukkah (6%) and 2% hand made cigarette. The mean age of starting smoking was 13(SD 2.9) years ranging from 9 to 20 years. More than one third (35%) of the student's father were smokers, whereas 11.5% of their brothers were smokers. Logistic analysis revealed that only age, sex and educational attainment appeared to be important predictors of smoking (p<0.001). This indicates that the smoking was 4.26 times high among male students than their female counterparts. It was 2.

Anwer Khan Modern Medical College Journal, 2012

metabolism in rodents. Also, several types of mushroom -Pleurotus Ostreatus 6 , Grifola Frondosa ... more metabolism in rodents. Also, several types of mushroom -Pleurotus Ostreatus 6 , Grifola Frondosa (maitake) 7 , Flammulina Velutips 7 , Lentinus Edodes (shitake) 8 , Ganoderma Lucidum 9 showed lowering effect of cholesterol synthesis or cholesterol absorption or by enhancement of fecal cholesterol excretion.

Engineering Journal, 2013

ABSTRACT

Journal of Nutrition, 2010

Information is limited on the effect of zinc in immune response in children with diarrhea due to ... more Information is limited on the effect of zinc in immune response in children with diarrhea due to enterotoxigenic Escherichia coli (ETEC), the most common bacterial pathogen in children. We studied the immunological effect of zinc treatment (20 mg/d) and supplementation (10 mg/d) in children with diarrhea due to ETEC. A total of 148 children aged 6-24 mo were followed up for 9 mo after a 10-d zinc treatment (ZT; n = 74) or a 10-d zinc treatment plus 3-mo supplementation (ZT+S; n = 74), as well as 50 children with ETEC-induced diarrhea that were not treated with zinc (UT). Fifty control children (HC) of the same age group from the same location were also studied. Serum zinc concentrations were higher in both the ZT (P , 0.001) and ZT+S groups (P , 0.001) than in the UT group but did not differ from the HC group. We found higher serum complement C3 immediately after zinc administration in both ZT (P , 0.001) and ZT+S (P , 0.001) groups than in the UT group. Phagocytic activity in children in both ZT (P , 0.01) and ZT+S (P , 0.01) groups was greater than in the UT group. However, oxidative burst capacity was lower in zinc-receiving groups (ZT, P , 0.001 and ZT+S, P , 0.001) than in the UT group. The naïve:memory T cell ratio in both ZT (P , 0.05) and ZT+S (P , 0.01) groups was higher than in the UT group from d 2 to 15. Increased responses, including complement C3, phagocytic activity, and changes in T cell phenotypes, suggest that zinc administration enhances innate immunity against ETEC infection in children. J. Nutr.

Sexually Transmitted Diseases, 2005

OBJECTIVE AND GOAL: The goal of this study was to study the prevalence of sexually transmitted in... more OBJECTIVE AND GOAL: The goal of this study was to study the prevalence of sexually transmitted infections (STIs)/reproductive tract infections (RTIs) among brothel-based sex workers (SWs) in Bangladesh. A cross-sectional study was conducted among SWs in 4 randomly selected brothels. A sociodemographic and behavioral survey and pelvic examination was conducted. Specimens including endocervical swab, high vaginal swab, and blood were collected and were examined for Neisseria gonorrhoeae, Chlamydia trachomatis, Trichomonas vaginalis, bacterial vaginosis candidiasis, and syphilis. A total of 439 SWs were enrolled and 49.6% had genital symptoms. Among all SWs, 17.5% were positive for N. gonorrhoeae; 15.5% for C. trachomatis; 7.5% for T. vaginalis, and 6.6% had active syphilis. A total of 67.4% SWs were positive for at least 1 cervical and/or vaginal infection. The prevalence of STIs/RTIs among SWs in brothels in Bangladesh is high. An intervention strategy addressing both symptomatic and asymptomatic infections and periodic screening of SWs for RTIs/STIs is essential for successful HIV and STIs prevention programs.

Journal of Reinforced Plastics and Composites, 2010

Jute fiber (hessian cloth)-reinforced polypropylene matrix composites (50 wt% fiber) were fabrica... more Jute fiber (hessian cloth)-reinforced polypropylene matrix composites (50 wt% fiber) were fabricated by compression molding. Tensile strength, tensile modulus, bending strength, bending modulus, and impact strength of the composites were found to be 48 MPa, 2.5 GPa, 56 MPa, 4.5 GPa, and 18 kJ/m 2 , respectively. Then E-glass fiber (woven)-reinforced polypropylenebased composites (50 wt% fiber) were fabricated and the mechanical properties were compared with those of the jute-based composites. It was revealed that E-glass fiber-based composites had almost double the mechanical properties as compared to jute composites. The interfacial shear strength of the jute and E-glass fiber-based systems was investigated and found to be 2.13 and 4.66 MPa, respectively, measured using the single-fiber fragmentation test. Fracture sides after flexural testing of both types of the composites were studied by scanning electron microscope and the results revealed poor fiber matrix adhesion for jute-based composites when compared to that of the E-glass fiber composites.

Journal of Medical Microbiology, 1992

We compared the usefulness of gene probes with standard bioassays to identify diarrhoeagenic Esch... more We compared the usefulness of gene probes with standard bioassays to identify diarrhoeagenic Escherichia coli amongst isolates from Bangladeshi children under 1 year of age with diarrhoea. E. coli isolates were analysed with specific gene probes for localised adhesiveness (LA), diffuse adhesiveness (DA), heat-labile toxin (LT), heat-stable toxin (ST), Shiga-like toxins (SLT I and SLT II), and enteroinvasiveness, and in bioassays for production of enterotoxins and cytotoxins, and for cell adherence. With 1136 isolates from 387 patients, there was general agreement between the two assay methods. When there was disparity, gene-probe-positive isolates gave negative results in the corresponding bioassay. In the HeLa cell adherence assay, 94% of the LA probe-positive isolates and 91.6% of the DA probe-positive isolates gave positive bioassay results for LA and DA respectively. Thirty-six of 39 LT probe-positive isolates and 73 of 86 ST probe-positive isolates gave positive results in the bioassays. Of 28 isolates that gave negative results in the suckling mouse assay but were initially positive with the probe for ST, 15 were later found to hybridize with the cloning vector for the ST probe. Addition of denatured vector DNA at a concentration of 10 micrograms/ml in the hybridisation solution eliminated these false positive results. None of the other probe-positive isolates hybridised with any of the cloning vectors used. The DNA hybridisation assay appeared to be a convenient alternative to bioassays for screening large numbers of isolates in epidemiological investigation.

Journal of Medical Microbiology, 1991

Entero-invasive Escherichia coli (EIEC) and shigellae were tested for contacthaemolysin (CH) with... more Entero-invasive Escherichia coli (EIEC) and shigellae were tested for contacthaemolysin (CH) with red blood cells (RBCs) of guinea-pig, rabbit, rat, mouse, monkey, man, sheep and chicken; all bacteria showed the best lysis with guinea-pig RBCs. The best culture medium for CH activity of shigellae was tryptic soy broth, and for EIEC it was casamino acid-yeast extract broth with 1 mM CaC12. CH production by all species was best at the slightly alkaline pH which is optimal for growth; it was also dependent on the presence of a large (140-Mda) plasmid. Pre-treatment of bacteria with homologous antisera inhibited CH activity. Various treatments of bacterial cells and RBCs suggested that CH may be a protein molecule, and that a chitotriose-like moiety may serve as CH receptor. RBCs that were incubated with bacteria at 4"C, or with heat-killed bacteria at 37"C, were not lysed; also, isolated cell-surface components (lipopolysaccharide and outer-membrane protein) did not lyse RBCs. This suggests that metabolically active cells are required for CH activity. Production of CH by both EIEC and shigellae is consistent with a common mechanism for the virulence of these organisms.