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Biomedical subjects

M I Huq

Publications and source records attributed to M I Huq.

At least 37 records · Page 2Linked to original sources
PubMed1984

Isolation of Yersinia enterocolitica and Y. intermedia from fatal cases of diarrhoeal illness in Bangladesh.

From three fatal cases of diarrhoeal illness in Bangladesh, Yersinia species were isolated from tissues at post-mortem examination. One patient was infected with Y. enterocolitica serotype 0:7, 8 and two patients were infected with Y. intermedia. These patients were infected also with other enteric pathogens. These findings suggest that Yersinia may be important as pathogens in tropical diarrhoea and as co-pathogens in serious disease.

Adult↗
PubMed1984

Experimental studies on the pathogenicity of Vibrio mimicus strains isolated in Bangladesh.

Vibrio mimicus, a newly described species of the genus Vibrio has been isolated from stools of 14 patients with diarrhoea. Live cells of all the 14 strains tested caused accumulation of fluid in rabbit gut loops and diarrhoea in infant rabbits. Culture filtrates of all the strains caused increased capillary permeability in rabbit skin; however, five of the filtrates resembled cholera toxin in that they gave positive reactions in rabbit loops, chinese hamster ovarian and mouse adrenal cell monolayers and GM1 ELISA tests and were neutralized by cholera antitoxin. None of the strains produced heat-stable toxin or possessed invasive capability as determined by Sereny's test. Thus, V. mimicus strains were divided into a group which produced a toxin immunobiologically similar to cholera toxin and the rest producing a heat-labile toxin unrelated to that of V. cholerae.

Animals↗
PubMed1984

A randomized, controlled trial of the toxin-blocking effects of B subunit in family members of patients with cholera.

A randomized, controlled field trial was performed to test the ability of B subunit, the nontoxic, binding portion of cholera toxin, to block the toxin receptors (GM1 ganglioside) in the small intestine and thereby prevent diarrhea in individuals infected with Vibrio cholerae O1. Of 1,922 family contacts of 370 index patients selected randomly to receive orally on two successive days either B subunit (low dose, 1.0 mg; high dose, 5.0 mg) or placebo, 190 were asymptomatically infected on day 1 or day 2 of the study and within 24 hr of receiving B subunit. During the first 24-hr period of follow-up, the relative risk of disease among contacts receiving B subunit versus placebo was 0.18 for the low dose (P = .08) and 0.50 for the high dose (P = .22). Subsequently the relative risk increased toward 1.0 and was at no single point significantly reduced, although in five of the six follow-up periods the risk of disease was less in the B subunit group.

Antitoxins↗
PubMed1984

Influence of water temperature, salinity, and pH on survival and growth of toxigenic Vibrio cholerae serovar 01 associated with live copepods in laboratory microcosms.

The influence of water temperature, salinity, and pH on the multiplication of toxigenic Vibrio cholerae serovar O1 cells and their attachment to live planktonic crustaceans, i.e., copepods, was investigated by using laboratory microcosms. By increasing water temperatures up to 30 degrees C, a pronounced effect on the multiplication of V. cholerae was demonstrated, as was attachment of the cells to live copepods. These were measured by culturable counts on agar plates and direct observation by scanning electron microscopy, respectively. Of the three salinities examined (5, 10, and 15%), maximum growth of V. cholerae and attachment to copepods occurred at 15%. An alkaline pH (8.5) was optimal both for attachment and multiplication of V. cholerae, as compared with pH 6.5 and 7.5. It is concluded that conditions affecting attachment of V. cholerae serovar O1 to live copepods observed under laboratory conditions may also occur in the natural estuarine environment and, thereby, are significant in the epidemiology of cholera.

Animals↗
PubMed1984

Isolation of enterotoxigenic, hemolytic, and antibiotic-resistant Aeromonas hydrophila strains from infected fish in Bangladesh.

Strains of Aeromonas hydrophila isolated from skin infections of common freshwater fish in Bangladesh were tested for enterotoxin production, hemolysin production, and any correlation between these two activities. We also tested the resistance patterns of A. hydrophila to different drugs, especially in relation to ampicillin. The A. hydrophila strains produced an enterotoxin that was related to their beta-hemolytic activities. Production of beta-hemolysin may thus be an indicator of enterotoxicity. As 50% of the strains of A. hydrophila were found to be susceptible to 12.5 micrograms of ampicillin per ml, media containing this antibiotic may not be suitable for their isolation.

Aeromonas↗
PubMed1984

Campylobacter jejuni diarrhea model in infant chickens.

To study the pathogenic mechanisms of Campylobacter jejuni infection, 36- to 72-h-old chickens were fed 10(3) to 10(6) live cells, using strains isolated from 40 patients with watery diarrhea and 6 with bloody mucoid diarrhea from whom no other known enteropathogen was detected. Chickens of Starbro strain were more likely to develop C. jejuni-induced diarrhea than were White Leghorn chickens. Diarrhea was defined on the basis of amounts of gut fluid in 288 chicks fed with live C. jejuni versus 183 saline-fed control as an accumulation greater than or equal to 0.4 ml of fluid in the guts (excluding ceca) of chickens. Twenty-five percent of the chickens developed diarrhea on day 2, 49% on day 4, and 81% on day 5. The intestines, including ceca, were distended with watery fluid. The majority of the strains, irrespective of whether they were isolated from watery or bloody mucoid enteritis patients, caused watery diarrhea in chickens, and a few caused mucoid diarrhea. No correlation was observed between the source of a strain and the outcome in the experimental model. Bloody diarrhea was never observed in chickens. The peak incidence of diarrhea on day 5 coincided with the mean of maximum fluid accumulation. The organisms multiplied by 3 to 4 logs in all parts of the intestine, with a steady increase in number until day 5. Systemic invasion occurred frequently: C. jejuni could be recovered from the spleen in 47% of the chickens on day 5, in 25% from the liver on day 6, and in 11% from heart blood on day 4. Histopathological examination of gut tissue of the chickens having watery diarrhea did not reveal any abnormality except slight submucosal edema. However, in chickens with mucoid diarrhea, the organisms were found to adhere to brush borders and penetrate into the epithelial cells with formation of a breach in continuity of the brush border lining. The electrolyte composition of the intestinal fluid from chickens infected with C. jejuni and from saline-fed controls did not show significant differences, except for depletion of K+ in the test group. The results obtained in this highly reproducible chicken diarrhea model indicate that (i) most chickens develop nonexudative watery diarrhea 2 to 5 days after oral feeding of 10(3) to 10(6) live cells of C. jejuni; (ii) the organism multiples in all parts of a chicken intestine, (iii) systemic invasion is common, and (iv) local invasion is sometimes observed.

Animals↗
PubMed1984

Usefulness of plasmid profiles for differentiation of Shigella isolates in Bangladesh.

We studied the plasmid profiles of 136 Shigella isolates in Bangladesh to determine whether plasmid profiles could be used for differentiation of strains for epidemiological studies. Many different plasmid patterns were observed within each species, indicating that many genetically different strains of Shigella are responsible for illness in Bangladesh.

Anti-Bacterial Agents↗
PubMed1983

Value of stool examination in patients with diarrhoea.

Findings of stool examinations in 1593 patients with diarrhoea due to a single enteric pathogen--enterotoxigenic Escherichia coli rotavirus, Shigella, Campylobacter jejuni, Vibrio cholerae 0:1, Entamoeba histolytica, or Giardia lamblia--were reviewed to determine how well they predicted the agent associated with the diarrhoea. Specimens were examined visually for blood and mucus, tested for pH, and examined under a microscope for the presence of red and white blood cells, parasites, and stool fat. Although visible blood was more common in specimens from patients infected with Shigella (51%) and Ent histolytica (39%) than in those from patients infected with other agents (6%; p less than 0.01), patients infected with Shigella were most likely to have numerous faecal leucocytes (greater than 50/high power field: 39% v 8% of all patients and 7% of patients infected with Ent histolytica, p less than 0.01 in both cases). Patients infected with enterotoxigenic E coli, rotavirus, V cholerae 0:1, or C jejuni had loose stools with fewer red or white cells. Patients infected with rotavirus and C jejuni were more likely to have acid stools with 3 to 4+ fat, but these findings were related to young age and breast feeding. Stool examination is most useful in establishing a diagnosis of dysentery and in helping to distinguish between patients infected with Shigella and Ent histolytica; it is of limited usefulness in discriminating between pathogens causing watery diarrhoea.

Adolescent↗
PubMed1983

Protection against cholera in breast-fed children by antibodies in breast milk.

We performed a prospective study to examine whether the IgA antibodies against cholera that are present in breast milk protect breast-fed infants and children against colonization with Vibrio cholerae 01 and disease. Among families of patients with cholera, we collected breast milk from mothers who had not had diarrhea in the previous week and monitored them and their breast-fed children for cholera colonization and diarrhea for 10 days. Breast milk was assayed for IgA antibodies to cholera toxin and lipopolysaccharide. Ninety-three mother--child pairs were studied; 30 infants became colonized with V. cholerae 01 and disease developed in 19. There were no differences between the antibody levels in milk fed to children who became colonized and in milk fed to children who did not. However, among the children who became colonized, those who had diarrhea drank breast milk containing significantly lower levels of both kinds of cholera antibodies than were present in the milk consumed by children who had no symptoms. We conclude that breast-milk antibodies against cholera do not appear to protect children from colonization with V. cholerae 01 but do protect against disease in those who are colonized.

Antibodies, Bacterial↗
PubMed1983

Classical Vibrio cholerae biotype displaces EL tor in Bangladesh.

The EL Tor biotype of Vibrio cholerae caused all endemic and epidemic cholera in Bangladesh from 1973 until Sept. 3, 1982, when the first classical strain was isolated from a patient in Matlab. Since then the number of isolations of the classical biotype has increased very rapidly and spread to other districts, replacing the EL Tor biotype as the main epidemic strain. The classical strains isolated in the 1982 outbreak were indistinguishable by the standard tests from those isolated a decade ago and the very few isolates in 1979, 1980, and 1981. This suggests that beyond the taxonomic traits used to identify the classical and EL Tor strains, there may be other more crucial biological characteristics that have given this new strain an advantage over the existing strains. The mechanism by which a new biotype of V. cholerae 01 achieves such a crucial biological advantage to displace the existing strains may be a key point in control of the global spread of cholera.

Bangladesh↗
PubMed1983

Seasonality of classical and El Tor cholera in Dhaka, Bangladesh: 17-year trends.

Data on the cholera patients admitted monthly to the ICDDR, B, hospital in Dhaka (Bangladesh) from 1964 through 1980 have been studied and analysed. Although Vibrio cholerae variant El Tor did not enter Bangladesh until 1963, it has completely displaced classical cholera since 1973. There have also been changes in seasonality, which are discussed.

Bangladesh↗
PubMed1983

Plasmid-borne multiple drug resistance in Vibrio cholerae serogroup O1, biotype El Tor: evidence for a point-source outbreak in Bangladesh.

In 1979, an outbreak of plasmid-borne, multiply drug-resistant Vibrio cholerae serogroup O1 biotype El Tor (V. cholerae O1) occurred in the Matlab area of Bangladesh. The outbreak could have resulted from the introduction into the area of a single resistant strain or from multiple conjugations of drug-sensitive V. cholerae O1 with C plasmids in other environmental flora. Resistant strains were phage typed to determine their relatedness, and plasmid studies were conducted to determine the frequency of C plasmids in nonvibrio flora of family contacts of cholera patients. Forty-one (85%) of 48 resistant strains of V. cholerae O1 examined belonged to two closely related phage types new to the area, whereas 59 drug-sensitive strains from the same period were primarily of two different phage types. Group C plasmids were in nonvibrio strains from five of 36 family contacts of patients with drug-resistant cholera but none of 82 family contacts of patients with sensitive cholera. This outbreak most likely began from the introduction into the area of a single, multiply drug-resistant strain of V. cholerae O1. C plasmids detected in the nonvibrio flora of family contacts probably came from the resistant strain of V. cholerae O1.

Anti-Bacterial Agents↗