Pathology of shigellosis and its complications

One hundred and thirty-three colonic biopsies of proven cases of Shigella colitis were examined and post-mortem examinations were carried out on 29 fatal cases at the International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR, B) hospital between 1988 and 1992. The distribution of pathological lesions and the spectrum of histopathological changes in the intestinal tract of these patients, and the features of intestinal and extra-intestinal complications of shigellosis are presented. Septicaemia, hyponatraemia, hypokalaemia and hypoglycaemia were present in a high percentage of these cases. All but two patients were malnorished at the time of autopsy. Shigellosis patients rapidly became hypoproteinaemic and were susceptible to other infections including opportunistic infections. Mortality amongst shigellosis patients admitted to our hospital continues to be high in spite of adequate antibiotic and supportive therapy.

Pathogenesis of Providencia alcalifaciens-induced diarrhea

Providencia alcalifaciens is a member of the family Enterobacteriaceae. There are reports that P. alcalifaciens can cause diarrhea, but the mechanism(s) by which it causes diarrhea is known. We studied P. alcalifaciens isolated from a child and two adults with diarrhea for enteropathogenicity. The three isolates did not exhibit any characteristic adherence to cultured HEp-2 cell monolayers, and they did not produce enterotoxins, cytotoxins, or keratoconjunctivitis in the Sereny test. Two isolates invaded cultured HEp-2 cell monolayers, producing localized bacterial clusters and actin condensation. The pattern of actin condensation was different from that produced by enteropathogenic Escherichia coli but similar to that produced by Shigella flexneri. Invasion and actin condensation were poor for the third isolate. Histology of adult rabbit small intestinal loops inoculated with all three isolates revealed bacterial attachment to, penetration of, and microulcer formation on the surface epithelium and hyperemia, edema, and polymorphonuclear cell infiltration of lamina propria. All the isolates produced diarrhea in rabbits with removable intestinal ties, and some of these rabbits developed hindlimb paralysis. Intestinal histology of the rabbits with removable intestinal ties which developed diarrhea showed changes similar to that in adult rabbits on which ileal loop assays had been performed. Transmission electron microscopy of intestinal tissues also confirmed tissue penetration by the isolates. Nerve tissue histology of two rabbits that developed hindlimb paralysis showed focal mononuclear cell infiltration around peripheral nerve sheaths. It is concluded that some strains of P. alcalifaciens are enteropathogenic and that they cause diarrhea by invading the intestinal mucosal epithelium. However, the relevance to human disease of the hindlimb paralysis observed in this animal model is not clear.

Sharing of virulence-associated properties at the phenotypic and genetic levels between enteropathogenic Escherichia coli and Hafnia alvei

Seven strains of Hafnia alvei isolated from diarrhoeal stools of children resembled enteropathogenic Escherichia coli (EPEC) in that they produced attaching-effacing (AE) lesions in rabbit ileal loops and fluorescent actin staining in infected HEp-2 cells. In addition, a DNA probe from a chromosomal gene required by EPEC to produce AE lesions, hybridised to chromosomal DNA from all seven H. alvei strains. These findings indicate that there is a sharing of virulence-associated properties at the phenotypic and genetic levels by H. alvei and EPEC. H. alvei strains with these properties should be considered diarrhoeagenic.

Outbreak of keratoconjunctivitis due to Salmonella weltevreden in a guinea pig colony

The purpose of this report is to demonstrate that the ability to produce keratoconjunctivitis (KC) is a property found in Salmonella weltevreden. This observation is contrary to previous reports that Salmonella spp. do not produce KC. An outbreak of KC due to S. weltevreden occurred in a guinea pig colony, and the animals carried the organism in the intestinal tract. The same Salmonella serotype that caused an epidemic of diarrhea in humans and a routine laboratory isolate also possessed the ability to induce KC. Unlike Shigella spp. (the prototype organisms positive for KC), S. weltevreden induced KC and bound Congo red dye even when grown at 30 degrees C. It invaded HeLa cells in culture but did not hybridize with a DNA probe for invasiveness of Shigella spp. and enteroinvasive Escherichia coli even though it harbored plasmids. It was susceptible to all the antibiotics tested, was hydrophobic, and showed mannose-sensitive hemagglutination. It did not have enterotoxic or cytotoxic activities.

An analysis of the empirical relationship between contraceptive prevalence and fertility in Bangladesh

"This paper presents an empirical relationship between contraceptive prevalence and fertility [in Bangladesh]. It also shows how much the level of contraceptive practice is to be raised to reach a targeted level of fertility on the assumption that all other intermediate variables that influence the fertility remain constant. Regression analysis has been used to measure the relationship. A formula derived from Bongaarts's model is used to find the level of contraceptive practice required to reach a targeted fertility." Data are from a variety of sources, including four contraceptive prevalence surveys carried out between 1979 and 1985, the 1975 Bangladesh Fertility Survey, and official statistical sources.

Multielement proton-induced X-ray emission analysis of Bangladeshi tobacco

The concentration of 12 different elements in cigarette tobacco of different brands, commercially made in Bangladesh, was determined using the proton particle-induced x-ray emission (proton PIXE) method. In all the present experiments, proton beams of 2.0 MeV (on the target in air) and about 30 nA current were used for characteristic x-ray excitation. The concentration of the elements (K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, Br, Rb and Sr) was determined by comparison with a calibration obtained from the NBS orchard leaf standard, SRM 1571. The results have been compared with available data on some foreign brands of tobacco and the probable reasons for the difference in the contents of some of the elements found in the Bangladeshi brands are discussed.

Some hereditary blood factors of the Bengali Muslim of Bangladesh (red cell enzymes, haemoglobins, and serum proteins)

In a sample of Bengali Muslems from Dacca, haptoglobin, group-specific component, haemoglobin, adenosine deaminase, adenylate kinase, 6-phosphogluconate dehydrogenase, phosphoglucomutase, acid phosphatase and several other red cell enzyme types were studied. For most serum protein and red cell enzyme systems the gene frequencies are similar to those in other populations to the west of Bangladesh, but others suggest affinity with populations to the east.

Comparative study on the cost benefit between indigenous and cross bred cows reared in rural area of Dinajpur District

A comparative study on cost benefit analysis of crossbred and indigenous cows reared under the small holder dairy was conducted in Dinajpur district of Bangladesh. A total of 70 dairy cows (20 crossbred and 50 indigenous) from rural level small and marginal dairy farmers (1-3 cows) were selected. Relevant information from the individual milk producers have been collected through personal interrogation method with the help of a structured data collection questionnaire prepared for the study. The cost involvement for feed, treatment and medication of crossbred cows were significantly higher (P<0.01) than the indigenous dairy cows. The per day milk production was found 1.86 ± 0.57 liter in indigenous cow whereas 5.94 ± 3.49 liter was in crossbred cows and income level from milk yields of crossbred cows were 3.19 times higher than the indigenous cows. The cost benefit ratio of rising crossbred and indigenous dairy cows were 1.19 and 1.26, respectively. The current rearing cost of crossbred cows is 2.71 times higher than indigenous cows. Considering the other traits it may be concluded that the raising of crossbred cows was more economic than the raising of indigenous cows. Since crossbred cows were more economical and gave higher yield than the indigenous cows inclusion of a few crossbred cows can increase the income of a dairy entrepreneur which improve the livelihood and provide round the year employment of its family labour. Key words: Cross bred cows; Indigenous cows; Income; expenditure; Cost benefit ratio DOI: http://dx.doi.org/10.3329/bjas.v39i1-2.9696 Bang. J. Anim. Sci. 2010, 39(1&2): 191-196

Seroprevalence and pathological study of Salmonella infections in layer chickens and isolation and identification of causal agents

The present research work was conducted to study about the seroprevalence and pathology of Salmonella infections in layer chickens of Dhaka and Gazipur regions of Bangladesh and to isolate and characterize Salmonellae from layer chickens during the period from January to May 2006. The used materials were blood sample, cloacal and liver swabs from live and dead birds respectively, and visceral organs (liver, lungs, spleen and intestine). The used methods were serum plate agglutination (SPA) test; necropsy and histopathology; cultural, morphological and biochemical test. The overall seroprevalence was 43.4%. During necropsy, congested and enlarged liver with focal necrosis, haemorrhagic and discoloured ovary with stalk formation and mild haemorrhagic to catarrhal enteritis in intestine were detected. Microscopically, the liver showed congestion, focal necrosis with multifocal infiltration of histiocytes in liver parenchyma. In ovum, infiltration of leukocytes, bacterial colony, RE cell proliferation and fibrinoid necrosis were recorded. The intestinal mucosa exhibited infiltration of mononuclear cells in mucosa, submucosa as well as muscularis mucosa. A total of 33 (21.02%) Salmonellae from live and dead birds were isolated. The isolation rate of Salmonellae was higher in seronegative (31.6%) group than seropositive (3.2%) group. Out of 33 Salmonella isolates, 25 were S. pullorum, 3 were S. gallinarum and the rest 5 were motile Salmonellae. The isolates obtained in the study may be investigated for serotyping, pathogenesis study, antibiogram and vaccine production in future. Key words: Seroprevalence, histopathology, isolation, identification, Salmonella, chickensDOI = 10.3329/bjvm.v4i2.1288Bangl. J. Vet. Med. (2006). 4 (2): 79–85

Avian Salmonella Infection: Isolation and Identification of Organisms and Histopathological Study

The Present study was performed in the Department of Pathology, BAU, Mymensingh during the period from January to December 2004. The study was conducted to determine the occurrence and pathology of pullorum disease, fowl typhoid and salmonellosis (paratyphoid infection) in dead chickens at necropsy in Mymensingh district of Bangladesh. A total of 70 samples (liver, ovary and intestine) were collected for isolation of bacteria in different media, and identification was performed based on the staining, cultural and biochemical properties of Salmonella spp. Routine histopathological method was used for the detection of tissue level alterations in Salmonella infected cases. Grossly, in all the infected cases the liver was enlarged and congested and in few cases, liver discoloration with focal necrosis. Old raised hemorrhages in the caecal tonsil and congested deformed ova were other important findings. There was catarrhal inflammation in the intestine. Microscopically, the section of livers showed congestion, hemorrhages, focal necrosis with infiltration of mononuclear cells. The pulmonary lesions consisted of sero-fibrinous exudation with mononuclear cell infiltration. The intestinal mucosa exhibited congestion, hemorrhages and infiltration of plasma cells, heterophils and macrophages. Out of 70 samples, 8 isolates were identified as Salmonella (11.42 %). Of them, five isolates were identified as Salmonella gallinarum, causative agent of fowl typhoid, one isolate was characterized as Salmonella pullorum, causative agent of pullorum disease and other two motile salmonella were identified as paratyphoid infection. Keywords: Fowl typhoid, pullorum disease, paratyphoid, histopathology, isolation, identification doi:10.3329/bjvm.v4i1.1518 Bangl. J. Vet. Med. (2006). 4 (1): 07-12