Complexing of Green Tea Catechins with Food Constituents and Degradation of the Complexes by Lactobacillus plantarum

Complexing of green tea catechins with food constituents and their hydrolysis by tannase-producing Lactobacillus plantarum strains, were investigated. Our observations indicated that 1) epigallocatechin gallate (EGCg) and other catechin galloyl esters bound with food ingredients (i.e., proteins) to form a complex that is likely to be unabsorbable through the intestinal wall, whereas most catechins not esterified with gallic acid (GA) remain in free form, not complexing with food ingredients; 2) tannase activity of L. plantarum is strain dependent, possibly grouped into those with high tannase activity hydrolyzing EGCg to epigallocatechin and GA and those with the low activity; and 3) L. plantarum strains with high tannase activity are capable of hydrolyzing not only intact EGCg but also EGCg and other catechin galloyl esters complexed with dietary proteins to free non-galloyl ester catechins and GA. The evidence suggests that L. plantarum with high tannase activity, if it colonizes the human intestine, would release free non-galloyl-ester catechins and GA that are readily absorbed through the human intestinal epithelia from the complexes, thereby ensuring maximum delivery of the bioactive polyphenols of green tea to the host.

Phenotypic and PCR-based identification of bacterial strains isolated from patients with suspected streptococcus suis infection in northern Thailand

Twenty bacterial strains isolated from the blood of patients with suspected Streptococcus suis infection based on clinical symptoms in northern Thailand between 2009 and 2010 were subjected to phenotypic and genotypic identification. Commercial identification kits and a PCR-based assay targeting the S. suis-specific 16S rDNA sequence correctly identified S. suis isolated from patients in northern Thailand; however, there was a risk of misidentifying S. gallolyticus as S. suis using a PCR assay targeting the S. suis-specific house keeping gene encoding glutamate dehydrogenase. This is the first paper to report S. gallolyticus infection in humans in Thailand.

Wide distribution of O157-antigen biosynthesis gene clusters in Escherichia coli

Most Escherichia coli O157-serogroup strains are classified as enterohemorrhagic E. coli (EHEC), which is known as an important food-borne pathogen for humans. They usually produce Shiga toxin (Stx) 1 and/or Stx2, and express H7-flagella antigen (or nonmotile). However, O157 strains that do not produce Stxs and express H antigens different from H7 are sometimes isolated from clinical and other sources. Multilocus sequence analysis revealed that these 21 O157:non-H7 strains tested in this study belong to multiple evolutionary lineages different from that of EHEC O157:H7 strains, suggesting a wide distribution of the gene set encoding the O157-antigen biosynthesis in multiple lineages. To gain insight into the gene organization and the sequence similarity of the O157-antigen biosynthesis gene clusters, we conducted genomic comparisons of the chromosomal regions (about 59 kb in each strain) covering the O-antigen gene cluster and its flanking regions between six O157:H7/non-H7 strains. Gene organization of the O157-antigen gene cluster was identical among O157:H7/non-H7 strains, but was divided into two distinct types at the nucleotide sequence level. Interestingly, distribution of the two types did not clearly follow the evolutionary lineages of the strains, suggesting that horizontal gene transfer of both types of O157-antigen gene clusters has occurred independently among E. coli strains. Additionally, detailed sequence comparison revealed that some positions of the repetitive extragenic palindromic (REP) sequences in the regions flanking the O-antigen gene clusters were coincident with possible recombination points. From these results, we conclude that the horizontal transfer of the O157-antigen gene clusters induced the emergence of multiple O157 lineages within E. coli and speculate that REP sequences may involve one of the driving forces for exchange and evolution of O-antigen loci.

Phenotypic and genotypic characterization of Vibrio cholerae clinically isolated in Surabaya, Indonesia

The phenotypic and genotypic characteristics of 6 clinical strains of Vibrio cholerae isolated in Surabaya, Indonesia in 2009 were examined. The DNA fingerprints obtained suggested that these isolates were not from a single clone. Furthermore, all isolates produced cholera toxin and possessed the classical type of toxin B subunit gene, thus meaning that this is the first report of the occurrence of El Tor variants of V. cholerae in Indonesia. Although all isolates were sensitive to almost all antibiotics tested, including ampicillin, chloramphenicol, ciprofloxacin, gentamicin, levofloxacin, kanamycin, nalidixic acid, norfloxacin, streptomycin, trimethoprim-sulfamethoxazole, and tetracycline, and had no mutation in the gyrA and parC genes, they nevertheless possessed the class 1 integron that is a molecular vehicle for the acquisition of antibiotic resistance genes, suggesting that they have the potential to acquire the genetic element for drug resistance.

Novel PCR-based genotyping method, using genomic variability between repetitive sequences of toxigenic Vibrio cholerae O1 El Tor and O139

A novel genotyping method for toxigenic Vibrio cholerae O1 El Tor and O139 was developed. The method was designed to amplify DNA sequences "sandwiched" between any given pair of repetitive sequences, "V. cholera repeats (VCR)", in highly polymorphic "integron island" of ca. 125 kb in the small chromosome of toxigenic V. cholerae so that the resultant PCR amplicons would present with a strain-specific electrophoretic pattern. The VCR-targeted PCR assay (VCR-PCR) for 37 strains of toxigenic V. cholerae O1 El Tor and O139 revealed that the O1 strains isolated before 1990 showed distinct clonality whereas those isolated after 1990 could be separated into two clones, one consisting of strains isolated from South American countries and another of those from other countries. By contrast, O139 strains were genotypically homogenous regardless of the geographic origin or time of isolation. VCR-PCR therefore would be a robust but rapid method for genotypic differentiation of toxigenic V. cholerae O1 El Tor and O139 strains and to recognize strains with epidemic potential.

Primary cutaneous CD30+ anaplastic large-cell lymphoma with generalized skin involvement and involvement of one peripheral lymph node, successfully treated with low-dose oral etoposide

Primary cutaneous CD30+ anaplastic large-cell lymphoma (PCALCL) in adults is rare, and the prognosis is generally excellent. Multifocal PCALCL tends to relapse after multiagent chemotherapy and is generally considered more prone to progress to extracutaneous involvement than is the localized disease. We report a 43-year-old woman with PCALCL who had generalized skin involvement accompanied by involvement of one peripheral draining lymph-node region. Although the disease relapsed after multiagent chemotherapy regimens, the disease was successfully treated with low-dose etoposide. We reviewed the previously reported cases of PCALCL treated with low-dose etoposide. We suggest that oral etoposide might be a useful effective treatment for treatment of relapsed multifocal PCALCL.

Endocarditis in chickens caused by subclinical infection of Streptococcus gallolyticus subsp. gallolyticus

Streptococcus gallolyticus subsp. gallolyticus causes endocarditis in humans and acute septicemia in domestic birds. We describe here the infective endocarditis caused by the bacterium found among clinically healthy broilers at two abattoirs in Japan. The chickens were thought to be healthy because of the lack of clinical symptoms and normal levels of mortality before slaughtering. At the time of inspection, some chickens were condemned because of organ disorders characterized by vegetative valvular endocarditis as well as focal necrosis in heart, liver, and spleen. Streptococcus gallolyticus subsp. gallolyticus was isolated from the organs as a pure culture, indicating that the bacterium probably was the causative agent of the disorders. Amplified fragment length polymorphism analysis of the isolates collected at the abattoirs from chickens grown in nine different farms indicated that the isolates were different variants of the same clonal lineage and may have been derived from the same ancestor. These results suggest that S. gallolyticus subsp. gallolyticus causes infectious endocarditis in chickens and that healthy chickens may possess the bacterium in their normal flora as an opportunistic pathogen.

Genetic analyses of the putative O and K antigen gene clusters of pandemic Vibrio parahaemolyticus

Pandemic V. parahaemolyticus strains have rapidly changed their serotypes, but its determinants, especially K antigen, and the genes involved in serotype have been an open question. The purpose of this study was to gain insights into these points. Although V. parahaemolyticus is known to be lacking O-side chain on its lipopolysaccharide, and O antigens are thought to be represented by core OS, the genome sequence of V. parahaemolyticus O3:K6 strain RIMD2210633 suggests that this bacterium potentially synthesizes O-side chain. To explore possible relatedness between this O-side chain biosynthesis gene cluster, which is similar in the serotypes of Vibrio cholerae, and of V. parahaemolyticus, we amplified both core OS and O-side chain gene clusters of the strains belonging to various serotypes of V. parahaemolyticus by long PCR and performed PCR RFLP analyses. The results of our RFLP analyses suggest that the core OS biosynthesis gene cluster is related to the O antigens of pandemic V. parahaemolyticus and that the putative O-side chain gene cluster is related to K antigens of pandemic V. parahaemolyticus. We then determined the sequence of these regions of a pandemic O4:K68 strain, and compared it with the corresponding sequence of RIMD2210633. In addition, PCR analysis showed the putative O4 and K68 antigen gene clusters are unique to the strains belonging to the O4 and K68 serotype respectively. The data implies that the pandemic O4:K68 V. parahaemolyticus strain emerged from the pandemic O3:K6 strain by replacement of the putative O and K antigen gene clusters.

Identification and cloning of a gene encoding tannase (tannin acylhydrolase) from Lactobacillus plantarum ATCC 14917(T)

The gene tanLpl, encoding a novel tannase enzyme (TanLpl), has been cloned from Lactobacillus plantarum ATCC 14917(T). This is the first report of a tannase gene cloned from a bacterial source other than from Staphylococcus lugdunensis, which has been reported elsewhere. The open reading frame of tanLpl, spanning 1410 bp, encoded a 469-amino-acid protein that showed 28.8% identity to the tannase of S. lugdunensis with several commonly conserved sequences. These sequences could not be found in putative tannases reported for other bacteria and fungi. TanLpl was expressed in Escherichia coli DH5alpha from a pGEM-T expression system and purified. SDS-PAGE analysis indicated that purified TanLpl was a monomer polypeptide of approximately 50 kDa in size. Subsequent enzymatic characterization revealed that TanLpl was most active in an alkaline pH range at 40 degrees C, which was quite different from that observed for a fungal tannase of Aspergillus oryzae. In addition, the Michaelis-Menten constant of TanLpl was markedly lower than that of A. oryzae tannase. The evidence suggests that TanLpl should be classified into a novel family of tannases.

Radiotherapy for extramammary Paget's disease: histopathological findings after radiotherapy

Several reports have suggested the efficacy of radiotherapy for treating extramammary Paget's disease (EMPD); however, these reports comprised only clinical observations, without in-depth histopathological observations. We report our experience of genital EMPD treated by radiotherapy in two elderly women, and the marked efficacy of radiotherapy, confirmed both by clinical observation and by detailed histopathological investigations. Our cases agree with the notion that radiotherapy is useful as an alternative therapy for EMPD, and should be considered particularly in elderly patients who may not tolerate surgery well.

Rapid detection of Actinobacillus actinomycetemcomitans using a loop-mediated isothermal amplification method

INTRODUCTION

Actinobacillus actinomycetemcomitans has been implicated in the etiology of aggressive periodontitis. In this study, we applied a novel nucleic acid amplification method, called loop-mediated isothermal amplification (LAMP), which amplifies DNA with high specificity, efficiency and rapidity under isothermal conditions, allowing the rapid detection of A. actinomycetemcomitans.

METHODS

We designed the primers for detecting A. actinomycetemcomitans and evaluated the specificity and sensitivity of the assay.

RESULTS

The LAMP primers used in this study successfully amplified serotypes a-e of A. actinomycetemcomitans, while other oral bacteria were not amplified. By measuring the precipitation of magnesium pyrophosphate, we could quantify the chromosomal DNA of A. actinomycetemcomitans. The detection limits using the real-time turbidimetry analysis were 5.8 x 10(2)-5.8 x 10(7) copies of A. actinomycetemcomitans template DNA per reaction tube. In addition, the LAMP assay was used for the rapid detection of A. actinomycetemcomitans in clinical specimens from eight individuals. The results with the LAMP method were similar to those using conventional polymerase chain reaction.

CONCLUSION

Our results suggest that the LAMP-based assay is very useful for the rapid detection of A. actinomycetemcomitans.

Bullous pemphigoid associated with dermatomyositis and colon carcinoma

It has been suggested that both bullous pemphigoid (BP) and dermatomyositis are associated with internal malignancies. However, there are no reports of the coexistence of these three conditions in one patient. We report the first case, to our knowledge. of coexistent BP, dermatomyositis and colon carcinoma. An 81-year-old Japanese woman was diagnosed with dermatomyositis based on muscular weakness and tenderness of the extremities, increased levels of circulating muscle enzymes and histological inflammatory changes in skeletal muscle and skin. Carcinoma of the sigmoid colon was detected during screening for internal malignancy; she was therefore surgically treated. Ten days after the operation, several large bullous eruptions appeared on her extremities. From the histopathological, immunofluorescence microscopy and BP180 ELISA study findings, we diagnosed the bullous eruptions as BP. Coexistence of BP with dermatomyositis or colon carcinoma is rare. Although the reason why our case exhibited these three disorders is not understood, it is suggested that these conditions may be associated with epitope spreading.

Intra-specific composition and succession of Bifidobacterium longum in human feces

Intra-species analysis of pulsed field gel electrophoresis (PFGE) on human fecal Bifidobacterium longum isolates revealed that a majority of 12 Japanese subjects harbored strains of unique PFGE types or subtypes over a 68-week period, suggesting that "indigenous"Bifidobacterium strains remain stable for a considerable time in each individual intestinal microbiota.

O Side Chain Deficiency Enhances Sensitivity of Escherichia coli to Shiga Toxin 2-Converting Bacteriophages

We investigated the relationship between expression of the O side chain of outer membrane lipopolysaccharide (LPS) and infection by a Shiga toxin 2 (Stx2)-converting phage in normal and benign strains of Escherichia coli. Of 19 wild-type E. coli strains isolated from the feces of healthy subjects, those with low-molecular-weight LPS showed markedly higher susceptibility to lytic and lysogenic infection by Stx2 phages than those with high-molecular-weight LPS. All lysogens produced infectious phage particles and Stx2. The Stx-negative E. coli O157:H7 strain ATCC43888 with an intact O side chain was found to be resistant to lysis by an Stx2 phage and lysogenic infection by a recombinant Stx2 phage, whereas a rfbE mutant deficient in the expression of the O side chain was readily infected by the phage and yielded stable lysogens. The evidence suggests that an O side chain deficiency leads to the creation of new pathotypes of Shiga toxin-producing E. coli (STEC) within the intestinal microflora.

Soft-agar-coated filter method for early detection of viable and thermostable direct hemolysin (TDH)- or TDH-related hemolysin-producing Vibrio parahaemolyticus in seafood

A novel method for detecting viable and thermostable direct hemolysin (TDH)-producing or TDH-related hemolysin (TRH)-producing Vibrio parahaemolyticus in seafood was developed. The method involved (i) enrichment culture, selective for viable, motile cells penetrating a soft-agar-coated filter paper, and (ii) a multiplex PCR assay targeting both the TDH gene (tdh) and TRH gene (trh) following DNase pretreatment on the test culture to eradicate any incidental DNAs that might have been released from dead cells of tdh- or trh-positive (tdh+ trh+) strains and penetrated the agar-coated filter. A set of preliminary laboratory tests performed on 190 ml of enrichment culture that had been inoculated simultaneously with ca. 100 viable cells of a strain of tdh+ trh+ V. parahaemolyticus and dense populations of a viable strain of tdh- and trh-negative V. parahaemolyticus or Vibrio alginolyticus indicated that the method detected the presence of viable tdh+ trh+ strains. Another set of preliminary tests on 190 ml of enrichment culture that had been initially inoculated with a large number of dead cells of the tdh+ trh+ strain together with dense populations of the tdh- and trh-negative strains confirmed that the method did not yield any false-positive results. Subsequent quasi-field tests using various seafood samples (ca. 20 g), each of which was experimentally contaminated with either or both hemolysin-producing strains at an initial density of ca. 5 to 10 viable cells per gram, demonstrated that contamination could be detected within 2 working days.

Lactobacillus apodemi sp. nov., a tannase-producing species isolated from wild mouse faeces

A Gram-positive, rod-shaped, non-endospore-forming bacterium, strain ASB1T, able to degrade tannin, was isolated from faeces of the Japanese large wood mouse, Apodemus speciosus. Comparative analysis of the 16S rRNA gene sequence revealed that the strain could be assigned as a member of the genus Lactobacillus. The nearest phylogenetic neighbours were determined as Lactobacillus animalis DSM 20602T (98.9 % 16S rRNA gene sequence similarity) and Lactobacillus murinus ASF 361 (98.9 %). Subsequent polyphasic analysis, including automated ribotyping and DNA–DNA hybridization experiments, confirmed that the isolate represents a novel species, for which the name Lactobacillus apodemi sp. nov. is proposed. The DNA G+C content of the novel strain is 38.5 mol%. The cell-wall peptidoglycan is of type A4α l-lys–d-Asp. The type strain is ASB1T (=DSM 16634T=CIP 108913T).

Role of Tannin-Binding Salivary Proteins and Tannase-Producing Bacteria in the Acclimation of the Japanese Wood Mouse to Acorn Tannins

We studied the defense mechanisms against the negative effects of tannins in acorns by using the Japanese wood mouse (Apodemus speciosus) and acorns of a Japanese deciduous oak Quercus crispula, which contain 9.9% tannins on a dry weight basis. For the experiment, we allocated 26 wood mice into two groups: acclimated (N = 12) and nonacclimated (N = 14). Mice in the nonacclimated group were fed only acorns for 10 d after 4 wk of receiving a tannin-free diet. In contrast, mice in the acclimated group received ca. 3 g acorns daily in addition to the tannin-free diet for the first 4 wk, then they were fed only acorns for 10 d. Body weight, food intake, and digestibility were monitored. In addition, the amount of salivary proline-rich proteins (PRPs) and abundance of tannase-producing bacteria (TPB) in the feces of mice were measured. Of the 14 mice in the nonacclimated group, 8 died, whereas only 1 of the 12 in the acclimated group died. During the first 5 d of feeding acorns only, mice in the nonacclimated group lost, on average, 17.5% of their body mass, while those in the acclimated group lost only 2.5%. Food intake, dry matter digestibility, and nitrogen digestibility were higher in the acclimated group than in the nonacclimated group. The results indicate that wood mice can mitigate the negative effects of tannins by acclimation. Path analysis revealed that increased secretion of PRPs and abundance of Lactobacillus type of TPB might explain the acclimation to tannins.

Spontaneous recombination between homologous prophage regions causes large-scale inversions within the Escherichia coli O157:H7 chromosome

It is known that XbaI-digested chromosomal DNAs of strains of Escherichia coli O157:H7 exhibit a wide variety in pulsed-field gel electrophoresis (PFGE) fragment patterns, which is used for epidemiological surveillance of this important pathogen. The variety in the restriction enzyme-digestion patterns suggests a wide genomic diversity, however, only a few studies have been conducted to investigate involvement of large-scale chromosomal rearrangements in development of the diversity. In this study, through rounds of subculturing E. coli O157:H7 strain EDL933, naturally occurring genome variation in the isolated derivatives was investigated. By comparing the PFGE patterns among clonally related derivatives, we found five types of large-scale inversions taking place within the chromosome. The five inversions found were across the replication axis and ranged from 250-kb to 1.4-Mb long, and all the corresponding recombination sites were associated with prophages or phage-like regions. Four inversions out of the five were resulted from recombination between pairs of lambda-like prophages disturbing the symmetry of the origin and terminus of the replication axis. These observations indicate that those prophage regions represent some of the hot spots for intrachromosomal recombination within the E. coli O157:H7 chromosome, where recombination between the prophage regions results not only in the large chromosomal inversions but might also in generation of chimeric phages.

Isolation of tannin-degrading bacteria isolated from feces of the Japanese large wood mouse, Apodemus speciosus, feeding on tannin-rich acorns

Bacteria with tannase activity were isolated from the feces of the Japanese large wood mouse, Apodemus speciosus. They were largely classified into two groups: Gram-positive cocci and Gram-positive bacilli. Genotypic analysis using a species-specific PCR assay as well as biochemical tests identified all cocci as Streptococcus gallolyticus. A PCR assay targeting a genus-specific sequence in the 16S/23S rDNA spacer region and additional 16S rDNA sequencing indicated that the bacilli belong to the genus Lactobacillus, with L. animalis and L. murinus being closely related taxa. Subsequent estimation of guanine-plus-cytosine content, amplified ribosomal DNA restriction analysis, and DNA/ DNA hybridization assay confirmed that the bacilli are homologous to each other but different from L. animalis or L. murinus. Consequently, a novel species of the genus Lactobacillus may be proposed. To date, this study is the first to report on the isolation of tannase-positive bacteria from the feces of a rodent species. These bacteria may play an essential role for the host organism in digesting tannin-rich acorns available in their natural habitats, thereby endowing them with a greater ecological advantage.

Identification of Vibrio parahaemolyticus pandemic group-specific DNA sequence by genomic subtraction

A genomic subtraction between a pandemic Vibrio parahaemolyticus and a nonpandemic strain that seemed to be clonally related was performed. A subtractive DNA fragment was identified to be a part of a 16-kbp insertion sequence which was present in almost all pandemic strains but not in nonpandemic strains tested.

PCR-based identification of pandemic group Vibrio parahaemolyticus with a novel group-specific primer pair

A PCR-based assay to identify pandemic group Vibrio parahaemolyticus has been developed. The assay employs an oligonucleotide primer pair derived from the group-specific sequence of an arbitrarily primed-PCR fragment, which is located in the genome encoding a "hypothetical protein," approximately 80% homologous to the Mn2+ and Fe2+ transporter of the NRAMP family of V. vulnificus. The assay distinguished the pandemic group from other V. parahaemolyticus strains by yielding a 235-bp specific amplicon, and can be a useful diagnostic tool for identification of pandemic group strains.

Genotypic analyses of lactobacilli with a range of tannase activities isolated from human feces and fermented foods

A total of 77 tannase producing lactobacilli strains isolated from human feces or fermented foods were examined for their genotypic profiles and intensities of tannase production. With a PCR-based assay targeting recA gene, all strains except one isolate were assigned to either Lactobacillus plantarum, L. paraplantarum, or L. pentosus whereas a 16/23S rDNA targeted PCR-based assay identified all except 6 isolates (inclusive of the above one isolate) as one of the closely related species. Subsequent DNA/DNA hybridization assays revealed that these 6 exceptional isolates showed low homology (between 1.2% and 55.8% relative DNA binding) against type strains of the three species. Supplemental carbohydrate fermentation profiles on the 6 isolates indicated that two of them were identified as L. acidophilus, one as Pediococcus acidilactici, one as P. pentosaceus, and two remained unidentifiable. The evidence suggests that the 16/23S rDNA targeted PCR assay can be used as a reliable identification tool for the closely related lactobacilli, and that the tannase gene is widely distributed within members of the Lactobacillaceae family. Meanwhile, a randomly amplified polymorphism DNA (RAPD) analysis revealed that all except 8 isolates were well allocated in 4 major RAPD clusters, though not species specific, consisting of two L. plantarum predominant clusters, one L. paraplantarum predominant, and one L. pentosus predominant. The RAPD patterns of the 8 non-clustered isolates, which consisted of the 6 unidentifiable isolates and 2 isolates identified as L. pentosus, were <40% similarity to those belonging to the 4 clusters. A quantitative assay of the tannase activities showed that there was a marked variation in the activities among the strains, which did not correlate with either species identification or clustering by RAPD.

Development of a diagnostic PCR assay targeting the Mn-dependent superoxide dismutase gene (sodA) for identification of Streptococcus gallolyticus

A PCR-based assay to identify Streptococcus gallolyticus has been developed. The assay uses an oligonucleotide primer pair targeting a partial sequence of the manganese-dependent superoxide dismutase gene (sodA). The assay distinguished members of the S. gallolyticus group from other, closely related taxa successfully by yielding a 408-bp specific amplicon.

Genotypic analyses of Vibrio parahaemolyticus and development of a pandemic group-specific multiplex PCR assay

A total of 54 Vibrio parahaemolyticus strains including pandemic O3:K6 strains and newly emerged O4:K68, O1:K25, O1:K26, and O1:K untypeable strains (collectively referred to as the "pandemic group") were examined for their pulsed-field gel electrophoresis (PFGE) and arbitrarily primed PCR (AP-PCR) profiles and for the presence or absence of genetic marker DNA sequences, toxRS/new or orf8, that had been reported elsewhere to be specific for the pandemic group. Both PFGE and AP-PCR analyses indicated that all strains of the pandemic group formed a distinct genotypic cluster, suggesting that they originated from the same clone. In addition to the pandemic group, four O3:K6 strains that did not possess the thermostable direct hemolysin (tdh) gene also belonged to this cluster and possessed the toxRS/new sequence. However, three O3:K6 strains that clearly belonged to the pandemic group by PFGE and AP-PCR did not possess the orf8 sequence. The evidence suggests that neither the toxRS/new nor the orf8 sequence is a reliable gene marker for definite identification of the pandemic group. We therefore developed a novel multiplex PCR assay specific for the pandemic group. The assay successfully distinguished pandemic group strains from other V. parahaemolyticus strains by yielding two distinct PCR products for tdh (263 bp) and the toxRS/new sequence (651 bp).

ARDRA and RAPD Analyses of Human and Animal Isolates of Streptococcus gallolyticus

A total of 23 Streptococcus gallolyticus strains, consisting of 12 strains from feces of healthy animals and 11 from clinical cases of human or cow mastitis milk, were examined genealogically. Four strains of S. bovis "biotype II/1" and 3 strains of S. equinus, the closely related organisms to S. gallolyticus, were also analyzed for outgroup comparison. Neither the amplified ribosomal DNA restriction analysis (ARDRA) nor the randomly amplified polymorphic DNA (RAPD) analysis that had been designed to recognize S. gallolyticus strains virulent in pigeons could differentiate clinical strains from the others of S. gallolyticus. No correspondence between the DNA profile in either analysis and the host animal species was detected.

A novel colorimetric method to quantify tannase activity of viable bacteria

A novel colorimetric method to quantify tannase activity of viable tannase-producing bacterial strains was developed through application of a visual reading method that was to detect the activity qualitatively. The novel method was sensitive enough to quantify the marginal tannase activity of strains that could not be otherwise measured by conventional spectrophotometric or colorimetric methods.

An improved enrichment broth for isolation of Escherichia coli O157, with specific reference to starved cells, from radish sprouts

An enrichment broth was developed for the efficient isolation of Escherichia coli O157 from radish sprouts. The broth was buffered peptone water containing 0.5% sodium thioglycolate (STG-BPW), which was designed to allow growth of E. coli O157 in starved and unstarved states. However, this medium suppressed the growth of non-carbohydrate-fermenting obligate aerobes whose colonial appearance on sorbitol MacConkey agar containing cefixime and tellurite (CT-SMAC) resembled that of E. coli O157. Both starved and unstarved cells of E. coli O157 experimentally inoculated into radish sprouts were successfully recovered with STG-BPW enrichment in all cases, most of which showed marked disappearance of E. coli O157-like colonies on CT-SMAC.

Effects of lysogeny of Shiga toxin 2-encoding bacteriophages on pulsed-field gel electrophoresis fragment pattern of Escherichia coli K-12

Escherichia coli K-12 lysogens of three different Shiga toxin 2 (Stx2)-encoding bacteriophages were examined for variability in their pulsed-field gel electrophoresis (PFGE) fragment patterns. The PFGE fragment patterns could be classified into three types (i.e., PFGE types B, C, and D). For the PFGE type D, a 255-kbp fragment present in the original K-12 strain was apparently shifted by the size of Stx 2-encoding phage genomic DNA (ca. 65 kbp) to the position at 320 kbp. In contrast, the types B and C showed the above fragment shift plus further 6- and 10-fragment differences, respectively, from the original K-12 strain. The evidence suggests that even a single genetic event like lysogeny can cause marked genotypic modification of the host strain.

Novel observation of hot-cold-hot hemolysis exhibited by group B streptococci

Six human isolates of group B streptococci (GBS) were cultured on blood agar anaerobically at 37 degrees C for 18 h and then at 4 degrees C for 6 h and reincubated anaerobically at 37 degrees C for 6 h. Three of the strains showed a marked enlargement of the hemolysis zone compared with that obtained after hot-only (37 degrees C for 18 h) or hot-cold (37 degrees C for 18 h and then 4 degrees C for 6 h) treatment. Subsequent broth culture experiments revealed that enhanced hemolytic activity due to hot-cold-hot treatment was observed in all 6 GBS strains when cultured in the presence of starch.

Effects of repeated subculturing and prolonged storage at room temperature of enterohemorrhagic Escherichia coli O157:H7 on pulsed-field gel electrophoresis profiles

Three clinical strains of enterohemorrhagic Escherichia coli O157:H7 which were subcultured repeatedly or stored at room temperature over a 25-week period showed appreciable variations in their pulsed-field gel electrophoresis fragment patterns. The variations could be explained by a couple of spontaneous genetic events at most and thus did not invalidate the genetic lineage of the strains.

Levels of thermostable direct hemolysin produced by Vibrio parahaemolyticus O3:K6 and other serovars grown anaerobically with the presence of a bile acid

Twenty-three V. parahaemolyticus strains, including 12 pandemic O3:K6 strains, were examined for their growth and production of thermostable direct hemolysin (TDH) under an anaerobic culture condition with or without presence of a bile acid, taurocholic acid (TCA). Both bacterial growth and TDH production were markedly enhanced by TCA for a majority of the strains, but the scale of the TDH production was disproportionately greater than that of the corresponding growth for 14 strains. Such enhancement was, however, not specific to the pandemic strains.

[Effect of probucol on the concentration of cyclosporin A in patients with nephrotic syndrome]

The first choice of therapy for nephrotic syndrome is steroid, and cyclosporin A(CyA) or other immunosuppressants are selected for steroid resistant or recurrent cases. Nephrotic syndrome accompanies hyperlipidemia for which HMG-CoA reductase inhibitors are mainly used. On the other hand, probucol is used in cases showing inadequate effects or some adverse reactions under treatment with HMG-CoA reductase inhibitors. Recently, we experienced several cases whose blood levels of CyA were decreased to about half that before the combined use of probucol, and concomitant administrations were discontinued. Based on these cases, we considered that the use of probucol should be prescribed in patients with nephrotic syndrome accompanying hyperlipidemia giving preference to CyA treatment. In cases of unavoidable usage of probucol, CyA dose adjustments are required on the basis of frequent CyA blood level monitoring.