Modified cold Z-N staining for presumptive identification of Brucella.

Brucellosis is one of the most common zoonotic diseases in India. Growth of Brucella is slow and needs meticulous biochemical tests and antisera for confirmation of the isolates. In the present study modified cold ZN staining was tried on the broth cultures for early presumptive identification of Brucella growth. Blood cultures were attempted in 22 seropositive patients. In the five blood cultures positive for Brucella, acid-fast coccobacilli were seen in broth smears stained with modified cold ZN stain, thus providing presumptive identification of Brucella growth. Acid-fast bacteria were not seen in the broth smears of the remaining 17 broths negative for Brucella growth. The method is simple, reliable and reproducible and needs to be evaluated further on a larger sample.

Human brucellosis in Northern Saudi Arabia

Analysis of the clinical features, laboratory findings, treatment given and complications seen in brucellosis patients at the Northern Area Armed Forces Hospital, Hafr Al-Batin, Kingdom of Saudi Arabia. We retrieved and reviewed the record charts of all patients from January 1995 to December 2001 with a clinical diagnosis of brucellosis whose brucella agglutination titre was 1:160 or greater from the Medical Records Department of Northern Area Armed Forces Hospital, Hafr Al-Batin. We extracted from the files the information on age, gender, occupation, history of raw milk or milk products ingestion, presenting symptoms and physical signs. We also noted the results of routine laboratory tests, treatment given, outcome of treatment and complications. One hundred and fifty-nine patients [males 101, females 58 with a ratio of 1.7:1] had a diagnostic label of brucellosis and a brucella titre of >/-1:160. Thirty-three [20.8%] were /-60 years. Fever [>/-=37.7oC] featured in 126 [79.2%] patients; joint pain in 112 [70.4%]; while 77 [48.4%] had bone pain. We recorded the abdominal pain in 18 patients [11.3%] vomiting in 9 [5.7%] and anorexia in 6 [3.8%]; splenomegaly in 6 [3.8]%, hepatomegaly and lymphadenopathy in 2 [1.3%] patients. Brucella tube agglutination titres ranged from 1:160 to 1:5120. Thirty-eight [35.8%] patients had anemia [Hb <12 gms/dl]; 12 patients [9.8%] had lymphocytosis [lymphocyte count >1 k/L]. Ten patients [6.2%] had bacteremia. We used Rifampicin and doxycycline in 87 cases [54.7%], doxycycline and streptomycin in 33 [20.8%], and rifampicin and streptomycin in 20 [12.6%] for 6 weeks or longer [we used combinations including septrin in the remaining patients]. We recorded relapse in 18 patients [11.3%]. Pneumonia, epididymo-orchitis in 2 cases [1.3%] each, abortion, threatened abortion in one case each, complicated the disease in these patients. Brucellosis is endemic in Northern Saudi Arabia as in other parts of the Kingdom. The clinical and laboratory features and response to therapy are also similar

Human brucellosis: review of an under-diagnosed animal transmitted disease.

Human brucellosis is an important animal transmitted disease of man. Although, the cases have been recorded all over the world, the prevalence is higher in developing countries. Lack of sufficient knowledge about the disease among the physicians, its under-diagnosis or misdiagnosis and absence of effective prevention and management strategies are attributed to the widespread of the disease. Increase in the occurrence of animal brucellosis has also resulted indirectly in an increase in the prevalence of human infection. Absence of characteristic clinical symptoms, chronic nature of the infection and difficulty in isolation of the causal agent from the patients make the diagnosis of the disease more difficult. The serological tests employed for diagnosing human brucellosis vary in terms of their sensitivity and specificity. Therefore, a combination of serological tests is desirable. Currently no vaccine is available against human brucellosis, which could check the spread of the disease effectively. It is suggested that clinicians investigate the cases of pyrexia of unknown origin (PUO) for brucellosis. It is desirable that specimens from cases of tuberculosis, typhoid, rheumatoid arthritis, urogenital infections, kala-azar, cirrhosis, bacterial endocarditis, leukemia and filariasis should also be screened for brucellosis in man. The cases of meningitis of unestablished etiology as the cases of human brucellosis are often misdiagnosed as cases of typhoid or tuberculosis.

On serch of bacterial species definition

The bacterial species concept was examined within the framework of plant and animal associated alpha-2 proteobacteria, taking into consideration the phylogenetic, taxonomic and biological approaches as well as the microbiologists' perception. The virtue of the phylogenetic approach is that it gives an evolutionary perspective of the bacterial lineage; however the methods used possess low resolution for defining species located at the terminal branches of the phylogenetic trees. The merit of the taxonomic approach is that species are defined on the basis of multiple characteristics allowing high resolution at the terminal branches of dendograms; its disadvantage is the inaccuracy in the earlier nodes. On an individual level, the qualitative biological characteristics used for the definition of species frequently reveal shortcomings because many of these properties are the result of coevolution, parallel evolution or the horizontal transfer of genes. Nevertheless, when considered together with the phylogenetic and taxonomic approaches, important uncertainties are discovered: these must be weighed if a practical definition of bacterial species is conceived. The microbiologists' perception is the criterion expressed by a group of sponsors who, based on scientific and practical grounds, propose a new bacterial species. The success of this new proposal is measured by its widespread acceptance and its permanence. A difficult problem concerned with defining bacterial species is how to distinguish if they are independent evolutionary units or if they are reticulate evolutionary units. In the first case the inherence is vertically transmitted as a result of binary fission and clonal expansion. This may be the case of some animal cell associated bacteria in which recombination appears to be precluded or exceptional. In the second case adaptive changes occurring within an individual can be horizontally transferred to many or all group members. This seems to be the condition of many intestinal and plant associated bacteria. Genetic drift and specialization in clonal bacteria will depend almost exclusively on mutation and internal genetic rearrangement processes, whereas specialization in reticulate bacteria will depend not only on these processes but in their genetic interactions with other bacterial strains. This uncertainty, which corresponds to the evolutionary process, is at the same time one of the key factors in defining a bacterial species