Vibrio cholerae isolates from environmental and clinical origins in the Bengal region in which epidemics of cholera break out periodically were analyzed with particular emphasis on the molecular epidemiological features. The presence of thevirulence genes ( ctxA, tcpA and toxR ) in the isolates was analyzed by the PCR (polymerase chain reaction) method. PFGE (pulsed-field gel electrophoresis) was performed to determine the clonal relationships between the clinical and environmental strains. Antibiograms and O serovars of the isolates were also examined. O1and O139 strains from both clinical and environmental sources were all positive for the three virulence genes while non-O1/non-O139 strains from both sources were all negative for ctxA and tcpA but positive for toxR. PFGE patterns of recent isolates of O1 and O139 were similar in each serovar regardless of origin, suggesting a clonal relationship between the clinical and environmental strains, although comparison with past isolates or isolates from different geographical area showed some differences.
The cleanability of titanium and 316L stainless steel particles was studied in terms of their apparent surface charge density ( σapp). Bovine serum albumin (BSA) was used as the model fouling agent. Curves for the σ aap of titanium and stainless steel particles showed the apparent points of zero charge (pzcapp) of 4.6 and 8.5, respectively. Compared withthe curve for the σapp of stainless steel, that of titanium was characterized by small positive and large negative σapp values.The isotherms for BSA adsorption and the saturation amount of BSA adsorbed on titanium and stainless steel depended largely on the intrinsic properties of BSA. In continuous cleaning in a plug-flow column fed by a 0.05M NaOH solution, BSA was found to be faster desorbed from titanium than from stainless steel, and smaller amounts of BSA remaining after 120-min cleaning were observed on titanium. Kinetic analysis showed that the two first-order desorption rate constants, reflecting the rate of BSA desorption in the initial and later stages of cleaning, for titanium were respectively 1.7-fold and 1.3-fold higher than those values for stainless steel. It could be suggested that the better cleanability of titanium was probably due to the small binding strength of BSA on slightly negatively-charged titanium surfaces and due to their large negative σapp values underalkalinecleaning conditions.
Seawater sample from the coral reefs of the Kerama Islands of Okinawa were assessed for the presence of carotenoid-producing bacteria. Results of 16S rDNA analysis of the bacteria obtained from the isolated bacteria showed unique patterns that were different from those of the bacteria obtained from the ordinary marine area. Phylogenetic analysis revealed a slight correlation with the statistical analysis of the PDA chart patterns. The results suggest that useful materials for human health such as carotenoids can be extracted from many carotenoid-producing bacteria such as those found the coral reefs the Kerama Islands.
Physiological activities of four types of phytoncide solutions (A, AB, CY and D-types), prepared from various plants widely distributed in nature, were examined. We assayed these phytoncide solutions, testing for active oxygen inhibition, DPPH radical scavenging effects, nitrogen monoxide inhibition, and lipid peroxide inhibition. The AB- and D-types of phytoncide solutions especially showed comparably potent antioxidant effects. Antibacterial and antifungal assays were conducted using the AB- and D-types, with results showing significant inhibitory activities with these solutions.
The susceptibility of Enterobacter sakazakii, a food-borne pathogen, to several metal-bound forms of bovine lactoferrin (LF), pepsin-hydrolyzed LF (LF-hyd), and LF-derived peptide lactoferricin B (LFcin B) was tested. MIC and MBC testing revealed that 4 strains of E. sakazakii show susceptibility to apo-and Cu-LF, LF-hyd, and LFcin B, but not to Fe-LF, similarly to Escherichia coll. A growth curve test indicated that E. sakazakii was inhibited in a dose-dependent manner by apo-LF at 0.5 to 8 mg/ml. Even after being heated at 80°C, LF at above 1 mg/ml inhibited the bacterial growth. These results suggest that bovine LF-related compounds may be useful for the inhibition of E. sakazakii in foods.