An outbreak of hepatitis E in an urban area of Bangladesh

We investigated an outbreak of jaundice in urban Bangladesh in 2010 to examine the cause and risk factors and assess the diagnostic utility of commercial assays. We classified municipal residents reporting jaundice during the preceding 4 weeks as probable hepatitis E cases and their neighbours without jaundice in the previous 6 months as probable controls. We tested the sera collected from probable cases and probable controls for IgM anti-hepatitis E virus (HEV), and the IgM-negative sera for IgG anti-HEV using a commercial assay locally. We retested the IgM-positive sera for both IgM and IgG anti-HEV using another assay at the Centre for Disease Control and Prevention (CDC), USA. Probable cases positive for IgM anti-HEV were confirmed cases; probable controls negative for both IgM and IgG anti-HEV were confirmed controls. We explored the local water supply and sanitation infrastructure and tested for bacterial concentration of water samples. Probable cases were more likely than probable controls to drink tap water (adjusted odds ratio: 3.4; 95% CI: 1.2-9.2). Fifty-eight percentage (36/62) of the case sera were IgM anti-HEV positive; and 75% of the IgM-positive samples were confirmed positive on retesting with another assay at CDC. Compared to confirmed controls, cases confirmed using either or both assays also identified drinking tap water as the risk factor. Two tap water samples had detectable thermotolerant coliforms. Research exploring decentralized water treatment technologies for sustainable safe water might prevent HEV transmission in resource-poor cities. Detection of serological markers in a majority of probable cases implied that available diagnostic assays could adequately identify HEV infection during outbreaks.

Clinicopathologic features and treatment outcome of urinary bladder neoplasm

More than ninety percent of bladder neoplasm is Transitional Cell Carcinoma (TCC). About 85% of patients present with symptom of painless haematuria. However haematuria is quite often intermittent so that a negative result has little meaning in ruling out the presence of bladder cancer. The present study was conducted to observe the natural history of different clinicopathologic stages of bladder cancer after transurethral resection bladder tumor (TURBT), either intravescical chemotherapy (IVC) or immunotherapy with BCG and of other forms of therapy like radio-chemotherapy (RCT) and radical surgery in few cases. A consecutive series of 52 cases with different grades and stages of bladder cancer patients were studied. Those who were noncompliant with surgery were sent for RCT. The age range of the patients was 34 to 75 with mean 53 year. Macroscopic haematuria, flank pain, microscopic haematuria, bladder irritability was found in 43(82.7%), 06(11.5%), 03(5.8%), 32(61.5%) cases respectively and coincidental ureteral TCC with hydronephrosis was found in 04(7.7%) cases for whom radical nephreureterectomy and cystectomy with ileal conduit was done. Amongst the other muscle invasive tumor only three cases were compliant to do radical surgery; rest were advised to consult with oncologist for possible RCT. Superficial bladder cancer was 19(36.5%) and invasive bladder cancer was 33(63.5%). TURBT and IVT were offered for all superficial bladder tumors. Of them 06(31.5%) patients showed recurrence during the study period. More recurrences occur in IVC group (35.7%) than immunotherapy with BCG group (20%) Re-TURBT and stage wise treatment was offered to them. All recurrent cases were G-3 tumor and were multifocal. Recurrence rate is about 30%. Screening program and structured referral system should be developed to have early diagnosis for prompt treatment and best prognosis.

Hygiene measures considering actual distributions of microorganisms in Japanese households

AIMS

Effective household hygiene measures require that sources of bacterial contamination and the places to which contamination spreads be carefully identified. Therefore, a study was performed to examine the distribution of microorganisms throughout ordinary households in Japan, which has its own unique customs of daily life and food preparation.

METHODS AND RESULTS

Using the stamping method, samples were taken from 100 different places and items in each of 86 households. This study found kitchens/dining rooms to have the greatest level of microbial contamination and bathrooms, the next highest level. Toilets (water closets) were found to have an unexpectedly low level of bacterial contamination. The largest bacterial counts were found on items such as drain traps, dish-washing sponges, counter towels, sinks, dish-washing tubs, and bathroom sponges.

CONCLUSIONS

It is necessary to carefully identify both the items that can become instruments for spreading bacterial contamination and the places that easily become subject to secondary contamination, and then to take timely and effective disinfection/sanitizing measures.

SIGNIFICANCE AND IMPACT OF THE STUDY

The data gathered in this study will be very valuable for anticipating the pathways over which bacteria are transported and prioritizing disinfection targets, to make effective disinfection possible.

Bacterial contamination of Japanese households and related concern about sanitation

The bacterial contamination of Japanese homes and the attitudes of Japanese people toward sanitation were studied. By taking bacterial counts of approximately 90 places each in five homes, this study found kitchens to have the greatest degree of bacterial contamination, followed by bathing rooms. Toilets had less bacterial contamination than was expected. While concern about bacteria on highly contaminated items such as sponges, towels for wiping counters, and other reservoirs/disseminators was common, there was a relative lack of concern regarding contact surfaces such as dining tables. It is believed that an in-depth study of bacterial contamination in the home and concern about it would lead to the promotion of greater public understanding of home sanitation and help to facilitate the provision of useful information and products to the public.

[Epidemiological investigation of tinea pedis in groups of healthy students, research workers and females wearing boots]

The infection rate, causative dermatophytes, and dermatophyte dissemination of tinea pedis in young healthy Japanese were studied by direct microscopic examination, slant cultures, and foot-press culture method. Questionnaires on subjective symptoms and treatments were also distributed. Among fifty-eight medical students with a mean age of 23.9 years, thirteen (22.4%) showed positive by direct microscopic examination and T. mentagrophytes was more dominant than T. rubrum by slant cultures. In one hundred and sixteen student feet, twelve were infected and disseminating dermatophytes, four were infected but not disseminating, three were not infected but adhering dermatophytes. The infection rate of tinea pedis was thus 24.1%. Among thirty-seven research workers (mean age: 34.8), twenty-one (56.8%) showed positive by direct microscopic examination. All the dermatophytes isolated by slant cultures were T. mentagrophytes. In seventy-four feet, twenty-nine were infected and disseminating, ten were infected but not disseminating, and three were adhering dermatophytes. The infection rate was 64.9%. Among thirty-one females wearing boots (mean age: 21.0), seven (22.6%) were infected and T. mentagrophytes was more dominant. In sixty-two feet, eight were infected and disseminating, one was infected but not disseminating, and five were adhering dermatophytes. The infection rate of tinea pedis was quite high and T.r/T.m rate was low in the three groups. Most of the patients had had no treatment and were disseminating dermatophytes.

Production of isopropyl cis-6-hexadecenoate by regiospecific desaturation of isopropyl palmitate by a double mutant of a Rhodococcus strain

Resting cells of a double mutant noted as KSM-MT66, derived from Rhodococcus sp. strain KSM-B-3 by UV irradiation, were found to cis-desaturate isopropyl hexadecanoate, yielding isopropyl cis-6-hexadecenoate. Addition of sodium glutamate (1.0%), Mg SO4 (2 mM), and thiamine (2 mM) increased the productivity of the unsaturated product in phosphate buffer. Optimal temperature and pH for the reaction were around 26 degrees C and 7, respectively. Under the optimized conditions, more than 50 g/l of isopropyl cis-6-hexadecenoate was produced after a 3-day incubation by resting cells of the mutant. Thus, cis-6-hexadecenoic acid, the main component of human sebaceous lipids, can be manufactured economically by the rhodococcal bioconversion.

Regiospecific internal desaturation of aliphatic compounds by a mutant Rhodococcus strain

A mutant Rhodococcus strain lacking the ability to utilize 1-chlorohexadecane was found to cis-desaturate aliphatic compounds, such as 1-chlorohexadecane, n-hexadecane, and heptadecanonitrile, yielding corresponding products with a double bond mainly at the ninth carbon from the terminal methyl groups. A new oxidative pathway involving the cis-desaturation step was suggested for alkane utilization by Rhodococcus spp.

Enzymatic properties of a novel liquefying alpha-amylase from an alkaliphilic Bacillus isolate and entire nucleotide and amino acid sequences

A novel liquefying alpha-amylase (LAMY) was found in cultures of an alkaliphilic Bacillus isolate, KSM-1378. The specific activity of purified LAMY was approximately 5,000 U mg of protein-1, a value two- to fivefold greater between pH 5 and 10 than that of an industrial, thermostable Bacillus licheniformis enzyme. The enzyme had a pH optimum of 8.0 to 8.5 and displayed maximum activity at 55 degreesC. The molecular mass deduced from sodium dodecyl sulfate-polyacrylamide gel electrophoresis was approximately 53 kDa, and the apparent isoelectric point was around pH 9. This enzyme efficiently hydrolyzed various carbohydrates to yield maltotriose, maltopentaose, maltohexaose, and maltose as major end products after completion of the reaction. Maltooligosaccharides in the maltose-to-maltopentaose range were unhydrolyzable by the enzyme. The structural gene for LAMY contained a single open reading frame 1, 548 bp in length, corresponding to 516 amino acids that included a signal peptide of 31 amino acids. The calculated molecular mass of the extracellular mature enzyme was 55,391 Da. LAMY exhibited relatively low amino acid identity to other liquefying amylases, such as the enzymes from B. licheniformis (68.9%), Bacillus amyloliquefaciens (66.7%), and Bacillus stearothermophilus (68.6%). The four conserved regions, designated I, II, III, and IV, and the putative catalytic triad were found in the deduced amino acid sequence of LAMY. Essentially, the sequence of LAMY was consistent with the tertiary structures of reported amylolytic enzymes, which are composed of domains A, B, and C and which include the well-known (alpha/beta)8 barrel motif in domain A.

Alkaline detergent enzymes from alkaliphiles: enzymatic properties, genetics, and structures

The cleaning power of detergents seems to have peaked; all detergents contain similar ingredients and are based on similar detergency mechanisms. To improve detergency, modern types of heavy-duty powder detergents and automatic dishwasher detergents usually contain one or more enzymes, such as protease, amylase, cellulase, and lipase. Alkaliphilic Bacillus strains are often good sources of alkaline extracellular enzymes, the properties of which fulfil the essential requirements for enzymes to be used in detergents. We have isolated numbers of alkaliphilic Bacillus that produce such alkaline detergent enzymes, including cellulase (CMCase), protease, alpha-amylase, and debranching enzymes, and have succeeded in large-scale industrial production of some of these enzymes. Here, we describe the enzymatic properties, genetics, and structures of the detergent enzymes that we have developed.

Amino acid sequence and molecular structure of an alkaline amylopullulanase from Bacillus that hydrolyzes alpha-1,4 and alpha-1,6 linkages in polysaccharides at different active sites

An amylopullulanase from alkalophilic Bacillus sp. KSM-1378 hydrolyzes both alpha-1,6 linkages in pullulan and alpha-1,4 linkages in other polysaccharides, with maximum activity in each case at an alkaline pH, to generate oligosaccharides (Ara, K., Saeki, K., Igarashi, K., Takaiwa, M., Uemura, T., Hagihara, H., Kawai, S., and Ito, S. (1995) Biochim. Biophys. Acta 1243, 315-324). Here, we report the molecular cloning and sequencing of the gene for and the structure of this enzyme and show that its dual hydrolytic activities are associated with two independent active sites. The structural gene contained a single, long open reading frame of 5,814 base pairs, corresponding to 1,938 amino acids that included a signal peptide of 32 amino acids. The molecular mass of the extracellular mature enzyme (Glu33 through Leu1938) was calculated to be 211,450 Da, a value close to the 210 kDa determined for the amylopullulanase produced by Bacillus sp. KSM-1378. The amylase and the pullulanase domains were located in the amino-terminal half and in the carboxyl-terminal half of the enzyme, respectively, being separated by a tandem repeat of a sequence of 35 amino acids. Four regions, designated I, II, III, and IV, were highly conserved in each catalytic domain, and they included a putative catalytic triad Asp550-Glu579-Asp645 for the amylase activity and Asp1464-Glu1493-Asp1581 for the pullulanase activity. The purified enzyme was rotary shadowed at a low angle and observed by transmission electron microscopy; it appeared to be a "castanet-like" or "bent dumbbell-like" molecule with a diameter of approximately 25 nm.

Separation of functional domains for the alpha-1,4 and alpha-1,6 hydrolytic activities of a Bacillus amylopullulanase by limited proteolysis with papain

An amylopullulanase (APase) from alkalophilic Bacillus sp. KSM-1378 hydrolyzes both alpha-1,6 linkages in pullulan and alpha-1,4 linkages in other polysaccharides, each maximally active at an alkaline pH, to generate oligosaccharides. We analyzed proteolytic fragments that were produced by exposing pure APase to various proteases, to identify its catalytic domain(s). The intact, pure 210-kDa APase was partially digested with papain for a short time, yielding simultaneously two smaller non-overlapping active fragments, designated amylose-hydrolyzing fragment (AHF114, 114 kDa) and pullulan-hydrolyzing fragment (PHF102, 102 kda). The two truncated protein fragments, each containing a single catalytic domain, were purified to homogeneity. The purified AHF114 and PHF102 had similar enzymatic properties to the amylase and pullulanase activities, respectively, of intact APase. The partial amino-terminal sequences of APase and AHF114 were both Glu-Thr-Gly-Asp-Lys-Arg-Ile-Glu-Phe-Ser-Tyr-Glu-Arg-Pro and that of PHF102 was Thr-Val-Pro-Leu-Ala-Leu-Val-Ser-Gly-Glu-Val-Leu-Ser-Asp-Lsy-Leu. These results were direct evidence that the alpha-1,6 and alpha-1,4 hydrolytic activities were associated with two different active sites in this novel enzyme. Our alkaline APase is obviously a "biheaded enzyme".

Purification and characterization of an alkaline amylopullulanase with both alpha-1,4 and alpha-1,6 hydrolytic activity from alkalophilic Bacillus sp. KSM-1378

The novel alkaline amylopullulanase produced by alkalophilic Bacillus sp. KSM-1378 was purified to an electrophoretically homogeneous state from culture medium. The purified enzyme was a glycoprotein with an apparent molecular mass of about 210 kDa and an isoelectric point of pH 4.8. The N-terminal amino acid sequence was Glu-Thr-Gly-Asp-Lys-Arg-Ile-Glu-Phe-Ser-Tyr-Glu-Arg-Pro and showed no homology to the N-terminal regions of other amylopullulanases reported to date. The enzyme was able to attack specifically the alpha-1,6 linkages in pullulan to generate maltotriose as the major end product, as well as the alpha-1,4 linkages in amylose, amylopectin and glycogen to generate various oligosaccharides. The pH and temperature optima for the pullulanase and alpha-amylase activities were pH 9.5 and 50 degrees C and pH 8.5 and 50 degrees C respectively. Both activities were strongly inhibited by well characterized inhibitors, such as diethyl pyrocarbonate and N-bromosuccinimide. The pullulanase activity was specifically inactivated by Hg2+ ions, alpha-cyclodextrin and beta-cyclodextrin while the amylase activity was strongly inhibited by EDTA and EGTA, although inhibition could be reversed by Ca2+ ions. It is suggested that the single alkaline amylopullulanase protein has two different active sites, one for the cleavage of alpha-1,4-linked substrates and one for the cleavage of alpha-1,6-linked substrates.

Determination of trace levels of fatty acid metal salts by high-performance liquid chromatography with fluorescence prelabeling

A simple method is described for picomole determinations of fatty acid metal salts. Fatty acid salts are directly labeled with 4-bromomethyl-7-methoxycoumarin in the presence of excess ethylenediaminetetraacetic acid tripotassium salt without any solvent extractions. The fluorescence derivatives of fatty acids are separated by reverse-phase high-performance liquid chromatography followed by fluorometric detection. The response of each fatty acid (C8-C18) calcium salt is linear from 1 to 50 micrograms/ml of samples. The detection limit is about 7 pmol. Good recoveries are obtained for the calcium salts of myrystic acid and soap (C8-C18, C18:1,2). The new method is successfully applied to the study on biodegradation of fatty acids in river water.

Uptake of paracetamol into brain and liver of rats

The time- and dose-dependent uptake of paracetamol into the brain and liver of rats was investigated and correlated with the serum levels of the drug. The results showed a rapid entry of paracetamol into the brain and liver: peak concentration of the drug was reached in these organs at 45 min after oral administration. The concentrations in the brain and liver were significantly higher (P less than 0.01) than in serum. The quick attainment of high concentration in the liver may explain the rapid onset of hepatotoxicity with a single large dose of the drug.