Assessment of adaptability of zebu cattle (Bos indicus) breeds in two different climatic conditions: using cytogenetic techniques on genome integrity.

The aim of this study was to evaluate the genome integrity so as to assess the adaptability of three breeds of indigenous cattle reared under arid and semi-arid regions of Rajasthan (Bikaner) and Haryana (Karnal) India. The cattle were of homogenous group (same age and sex) of indigenous breeds viz. Sahiwal, Tharparkar and Kankrej. A total of 100 animals were selected for this study from both climatic conditions. The sister chromatid exchanges (SCE's), chromosomal gaps and chromatid breaks were observed in metaphase plates of chromosome preparations obtained from in vitro culture of peripheral blood lymphocytes. The mean number of breaks and gaps in Sahiwal and Tharparkar of semi-arid zone were 8.56 ± 3.16, 6.4 ± 3.39 and 8.72 ± 2.04, 3.52 ± 6.29, respectively. Similarly, the mean number of breaks and gaps in Tharparkar and Kankrej cattle of arid zone were 5.26 ± 1.76, 2.74 ± 1.76 and 5.24 ± 1.84, 2.5 ± 1.26, respectively. The frequency of SCEs in chromosomes was found significantly higher (P < 0.05) in Tharparkar of semi-arid region (4.72 ± 1.55) compared to arid region (2.83 ± 1.01). Similarly, the frequency of SCEs was found to be 4.0 ± 1.41 in the Sahiwal of semi-arid region and 2.69 ± 1.12 in Kankrej of arid zone. Statistical analysis revealed significant differences (P < 0.05) amongst the different zones, i.e. arid and semi-arid, whereas no significant difference (P > 0.05) was observed in the same zone. The analysis of frequency of CAs and SCEs revealed significant effects of environmental conditions on the genome integrity of animals, thereby indicating an association with their adaptability.

Epstein-Barr virus-induced haemophagocytic syndrome.

Haemophagocytic syndrome or haemophagocytic lymphohistiocytosis is a disorder of histiocytes that has sepsis-like features, combined with haemophagocytosis, cytopenias, hyperferritinaemia, hypercytokinaemia and splenomegaly. Diagnostic, therapeutic and prognostic guidelines are available for childhood (familial) haemophagocytic syndrome. The disorder is diagnosed less frequently among adults than children. We report a case of Epstein-Barr virus-induced haemophagocytic syndrome in a 23-year-old man, who responded to treatment with steroids and chemotherapy.

Development and validation of an automated, microscopy-based method for enumeration of groups of intestinal bacteria.

An automated microscopy-based method using fluorescently labelled 16S rRNA-targeted oligonucleotide probes directed against the predominant groups of intestinal bacteria was developed and validated. The method makes use of the Leica 600HR image analysis system, a Kodak MegaPlus camera model 1.4 and a servo-controlled Leica DM/RXA ultra-violet microscope. Software for automated image acquisition and analysis was developed and tested. The performance of the method was validated using a set of four fluorescent oligonucleotide probes: a universal probe for the detection of all bacterial species, one probe specific for Bifidobacterium spp., a digenus-probe specific for Bacteroides spp. and Prevotella spp. and a trigenus-probe specific for Ruminococcus spp., Clostridium spp. and Eubacterium spp. A nucleic acid stain, 4',6-diamidino-2-phenylindole (DAPI), was also included in the validation. In order to quantify the assay-error, one faecal sample was measured 20 times using each separate probe. Thereafter faecal samples of 20 different volunteers were measured following the same procedure in order to quantify the error due to individual-related differences in gut flora composition. It was concluded that the combination of automated microscopy and fluorescent whole-cell hybridisation enables distinction in gut flora-composition between volunteers at a significant level. With this method it is possible to process 48 faecal samples overnight, with coefficients of variation ranging from 0.07 to 0.30.

Healthy individuals possess circulating antibodies against their indigenous faecal microflora as well as against allogenous faecal microflora: an immunomorphometrical study.

Healthy persons were shown to possess circulating antibodies of both IgA, IgG and IgM isotype directed against the bacteria of their faecal microflora, assessed by immunomorphometry. After removal, by absorption, of the fraction of antibodies directed against the autochthonous faecal bacteria or cross-reacting with allogenous faecal bacteria, there were still antibodies left directed against allogenous faecal bacteria of both the IgA, IgG and IgM isotype. However, relatively more antibodies of the IgA isotype appeared to be directed against allogenous bacteria than against indigenous faecal bacteria. Persons who reacted with specific antibodies to many bacteria of their own flora also tended to react specifically to bacteria in the allogenous microflora of the other volunteers. The patterns of antibodies directed to faecal bacteria of different morphologies (morphotypes) were unique for each individual.

The in vitro inactivation of thirteen beta-lactam antibiotics by other mechanisms than adsorption to faecal substance.

We have investigated the antibiotic inactivating capacity of intestinal contents in vitro in faeces. In the presently reported study the influence of beta-lactamase catalyzed hydrolysis on the antimicrobial activity of 13 commonly used beta-lactam antibiotics was investigated, while the influence of non-specific adsorption of antibiotics to faecal compounds was also taken into account. The following antibiotics were tested: benzylpenicillin, amoxicillin, amoxicillin/clavulanate, cloxacillin, piperacillin, temocillin, cefuroxime, cefamandole, cephradine, cefotaxime, ceftazidime, aztreonam and imipenem. Faecal samples were obtained from 30 healthy volunteers. Six different concentrations of each antibiotic were added to 1 g of faeces. After 24 h of incubation at 37 degrees C the remaining amount of active antibiotic was determined by means of a "growth inhibition assay". The contribution to the test results of non-specific adsorption to macromolecules was calculated by means of a model and the inactivation data were subsequently corrected. The amount of antibiotic non-specifically bound to faecal macromolecules varied from 0% to 80% of the amount of antibiotic initially added to the faeces. A considerable difference was found in the degree of inactivation of several antibiotics. However, in contrast to earlier investigations, the results of this study show that in a normal population the influence of beta-lactamase catalyzed hydrolysis on the activity of beta-lactam antibiotics is apparently very small when compared to the influence of non-specific adsorption of beta-lactam antibiotics to faecal compounds.

The non-enzymatic inactivation of thirteen beta-lactam antibiotics in human faeces.

In order to obtain a method that could predict the in vitro inactivation of an antibiotic in the digestive tract, the non-enzymatic inactivation of 13 beta-lactam antibiotics by human faeces was investigated. Benzylpenicillin, amoxicillin, amoxicillin/clavulanate, cloxacillin, piperacillin, temocillin, cefuroxime, cefamandole, cephradine, cefotaxime, ceftazidime, aztreonam and imipenem were mixed in six graded concentrations with faecal suspensions of 30 healthy volunteers. After incubation the remaining antimicrobial activity was measured by means of a serial dilution method. A relationship between the initial antibiotic concentration (Aia) and the remaining antimicrobial activity after incubation (Asd) was derived, namely: Asd = 1/2[(Aia-K-F)+square root ((Aia-K-F)2 + 4 K Aia)]. The parameters K and F represent the intrinsic dissociation constant and the amount of available bindingsites in the faeces, respectively. Asd values were predicted with a reasonable degree of accuracy for all thirteen antibiotics. Dissociation constants differed significantly between the penicillins and the cephalosporins but F- values did not differ between cephalosporins and penicillins.

The effect of ceftriaxone on the anaerobic bacterial flora and the bacterial enzymatic activity in the intestinal tract.

The normal flora of the intestinal tract, mainly consisting of anaerobic bacteria, protects the host against colonization by pathogenic microorganisms. Antimicrobial treatment with ceftriaxone may influence the colonic microflora and as a consequence, the protective effect. Ten healthy volunteers received 1 g of ceftriaxone intramuscularly for five days. This resulted in a significant decrease (p less than 0.05) of the mean cultural counts (+/- SEM) of total anaerobes from 10.67 (0.11) (prior to treatment) to 9.02 (0.45) and 8.97 (0.46) at days 3 and 5, respectively (during treatment). After treatment (days 10 and 15-19), the cultural counts of anaerobes returned to 10.17 (0.16) and 10.44 (0.18), respectively. Bacterial enzymes may serve as an indicator of protective microflora. beta- aspartylpeptidase and deoxycholate hydrolase activity was determined in faecal supernatants of the volunteers and compared with anaerobic culturing. Both enzymatic activities show a significant correlation with the total number of anaerobes present at day 3 of deftriaxone treatment. At day 5 and 8 only beta-aspartylpeptidase showed significant correlations with cultural counts of total anaerobes, Bacteroides spp. or bifidobacteria. At day 15 to 19 (ten to 14 days after treatment) beta-aspartylpeptidase showed only a significant correlation with the number of Bacteroides spp. This indicates that changes in the indigenous bacterial flora during and shortly after treatment with ceftriaxone can be monitored by determination of beta-aspartylpeptidase. Recovery of the intestinal flora is difficult to assess in this manner.

Effect of intramuscular ceftriaxone on aerobic oral and faecal flora of 11 healthy volunteers.

11 volunteers received 1 g ceftriaxone i.m. every 24 h for 5 consecutive days. Volunteers were selected on the basis of the "ceftriaxone inactivating capacity" of their faeces, which should be 250 mg/kg faeces. The effect of treatment on the aerobic oral and faecal flora was studied. In the oral flora a temporary suppression of the viridans streptococci occurred, which normalised already during treatment. More spectacular was the effect on the faecal flora: suppression of aerobic Gram-negative bacilli with overgrowth of yeasts and enterococci. Two weeks after treatment the results of the faecal cultures were almost the same as before treatment in most of the volunteers. One volunteer experienced severe diarrhoea, starting the day after completion of ceftriaxone treatment and lasting 2 days.