Five Cases of the Gram Variable Bacterium Paenibacillus urinalis Isolated from Clinical Specimens and its Clinical Significance

Paenibacillus urinalis was first isolated from the urine of a woman in 2008, and was reported to be a contaminant. Here, we report 5 cases of P. urinalis isolated over 5 months at a tertiary hospital. Using an API kit, 4 cases were classified as Cellulomonas species. Owing to the low reliability of API kit results and Gram stain results indicating gram variable bacilli for few specimens, MALDI-TOF MS and 16S rRNA gene sequencing were performed for identification. The last case showed Gram variable bacilli, and therefore, based on previous experience, 16S rRNA gene base sequence analysis was carried out without an additional API kit. All isolated strains were confirmed to be P. urinalis, and were judged to be contaminants. As for Gram variable bacteria, the use of current biochemical identification systems may lead to misidentification as other bacteria, which may cause unnecessary or improper use of antibiotics. Moreover, whereas most of the Paenibacillus species are reported to be contaminants, some of them are being reported as sources of infection. Therefore, more accurate identification will be necessary in the future. Accordingly, it is expected that accurate identification of this genus will help clinical physicians make decisions regarding appropriate treatment and use of antibiotics.

A Case of Arcanobacterium haemolyticum Bacteremia and Osteomyelitis Diagnosed by 16s rRNA Sequencing / 감염과화학요법

Arcanobacterium haemolyticum is a catalase-negative, aerobic gram-positive rod. It causes pharyngitis, skin and soft tissue infection, osteomyelitis, endocarditis, meningitis, pneumonia, and septicemia. We experienced a case of A. haemolyticum bacteremia and osteomyelitis in a diabetic patient. The organism was misidentified as Cellulomonas species by automated system but correctly identified as A. haemolyticum by 16s rRNA sequencing.

Effect of different growth parameters on endoglucanase enzyme activity by bacteria isolated from coir retting effluents of estuarine environment

The cellulolytic enzyme-endoglucanase activity against coir fibre, a major biowaste by bacteria such as Cellulomonas, Bacillus and Micrococcus spp. isolated from coir retting effluents of estuarine environment was studied. The enzyme assay was carried out by using various concentrations [0.5 - 2%] of substrate of coir powder as a carbohydrate in different pH [5 - 9] and temperature [20 - 50 °C]. The enzyme activity was minimum in 0.5% substrate concentration at lower pH 5 [0.0087, 0.0143 and 0.0071 U/mL] and at 20 °C temperature [0.0151, 0.0154 and 0.0122 U/mL] by the bacterial strains such as Cellulomonas, Bacillus and Micrococcus spp respectively. Then this level was increased and reached maximum at the neutral pH [0.0172, 0.0165 and 0.0121 U/mL] and at 40 °C [0.0336, 0.0196 and 0.0152 U/mL] by the selected bacterial species. Further increase of pH and temperature, the enzyme activity reduced considerably to 0.0083, 0.0143 and 0.0037 U/mL at pH 9 and 0.0154, 0.0197 and 0.0121 U/mL at 50 °C by the tested bacterial strains. The same trend was also obtained in oth er substrate concentrations such as 1.0, 1.5 and 2.0%. With in the four substrate concentrations, the endoglucanase enzyme activity was more in 1.5% concentration at the tested pH and temperatures. From the over all result, it was observed that, among the three bacterial strains, the enzyme activity was more in Cellulomonas sp, followed by Bacillus andMicrococcus spp. in varying pH and temperature

Influence of various fermentation variables on exo-glucanase production in Cellulomonas flavigena

The influence of carbon and nitrogen sources on the production of exo-glucanase was investigated. The enzyme production was variable according to the carbon or nitrogen source used. Levels of beta-cellobiohydrolase (CBH) were minimal in the presence of even low concentrations of glucose. Enzyme production was stimulated by other carbohydrates and thus is subject to carbon source control by easily metabolizable sugars. In Dubos medium, on cellobiose, the cellobiohydrolase titres were 2-to 110-fold higher with cells growing on monomeric sugars and 2.7 times higher than cells growing on other disaccharides. alpha-Cellulose was the most effective inducer of beta-cellobiohydrlase and filter paperase (FPase) activities, followed by kallar grass straw. Exogenously supplied glucose inhibited the synthesis of the enzyme in cultures of Cellulomonas flavigena. Nitrates were the best nitrogen sources and supported greater cell mass, cellobiohydrolase and FPase production. During growth on alpha-cellulose containing 8-fold sodium nitrate concentration, maximum volumetric productivities (Qp) of beta-cellobiohydrolase and FPase were 87.5 and 79.5 IU/l./h respectively and are significantly higher than the values reported for some other potent fungi and bacteria.