Based upon precise genetic techniques, our results clearly support the fecal-perineal-urethral hypothesis, indicating that E. coli strains residing in the rectal flora serve as a reservoir for urinary tract infections, e.g., cystitis.

A potential antagonist, Bacillus amyloliquefaciens strain RC-2, against Colletotrichum dematium, mulberry anthracnose fungus, was obtained from healthy mulberry leaves by in vitro and in vivo screening techniques. Application of culture filtrate of RC-2 inhibited disease on mulberry leaves, indicating that suppression was due to antifungal compounds in the filtrate. Development of mulberry anthracnose on mulberry leaves was inhibited only when the culture filtrate was applied before fungal inoculation, and it was not inhibited by application after inoculation. These results suggest that the antifungal compounds in the filtrate exhibit a preventive effect on the disease. Peptone significantly increased production of the antifungal compounds. The culture filtrate of RC-2 also inhibited the growth of several other phytopathogenic fungi and bacteria, such as Rosellinia necatrix, Pyricularia oryzae, Agrobacterium tumefaciens, and Xanthomonas campestris pv. campestris, in vitro. From the culture filtrate of RC-2, seven kinds of antifungal compounds were isolated by high performance liquid chromatography analysis, and one of the compounds was determined as iturin A2, a cyclic peptide, by nuclear magnetic resonance and fast atom bombardment mass analysis.

Characteristics of

Histamine fish poisoning is caused by histamine-producing bacteria (HPB). Klebsiella pneumoniae and Klebsiella oxytoca are the best-known HPB in fish. However, 22 strains of HPB from fish first identified as K. pneumoniae or K. oxytoca by commercialized systems were later correctly identified as Raoultella planticola (formerly Klebsiella planticola) by additional tests. Similarly, five strains of Raoultella ornithinolytica (formerly Klebsiella ornithinolytica) were isolated from fish as new HPB. R. planticola and R. ornithinolytica strains were equal in their histamine-producing capabilities and were determined to possess the hdc genes, encoding histidine decarboxylase. On the other hand, a collection of 61 strains of K. pneumoniae and 18 strains of K. oxytoca produced no histamine.Histamine fish poisoning (HFP) caused by eating spoiled fish happens throughout the world (2, 3). HFP is usually a rather mild illness; however, serious complications, such as cardiac and respiratory manifestations, occur rarely in individuals with preexisting conditions (12). The implicated fish are mainly of the families Scomberesocidae and Scombridae (the so-called scombroid fish) and contain large amounts of histamine (21). A hazardous level of histamine is produced by the microbial decarboxylation of the free histidine in the muscular tissue of fish. Enteric bacteria have been reported to be the dominant histamine-producing bacteria (HPB) in fish (19). In 1979, Taylor et al. reported that histamine-producing Klebsiella pneumoniae strain T2 was isolated from spoiled tuna sashimi (20). K. pneumoniae has been the best-known HPB ever since that report, and Klebsiella oxytoca is also known as an HPB from fish (13). However, K. pneumoniae strain T2 was later sent to the American Type Culture Collection (now in Manassas, Va.) and identified as Klebsiella planticola (ATCC 43176) in 1987. This strain has been reported to possess the hdc genes, encoding pyridoxal phosphate-dependent histidine decarboxylase (8).In 1981, Bagley et al. proposed the name Klebsiella planticola for "Klebsiella species 2" to distinguish it from both K. pneumoniae and K. oxytoca (1). Moreover, K. planticola, together with Klebsiella ornithinolytica and Klebsiella terrigena, was classified in the new genus Raoultella in 2001 (5). Nevertheless, Raoultella planticola cannot be distinguished from K. pneumoniae or K. oxytoca by using commercialized systems, such as API 20E (Biomérieux, Marcy l'Etoile, France). Additional tests are necessary to differentiate R. planticola from Klebsiella species (14, 15). Similarly, in 1989 the name Klebsiella ornithinolytica was proposed for "NIH group 12" at the National Institute of Health, Tokyo, Japan, and "Klebsiella group 47" at the Centers for Disease Control, Atlanta, Ga., which showed positive reactions in indole production and ornithine decarboxylase tests (6, 18). K. ornithinolytica was also classified in the genus Raoultella.K. pneumoniae and K. oxytoca had been shown to be HPB in several reports, whereas R. planticola had ...

Histamine-producing bacteria (HPB) such as Photobacterium phosphoreum and Raoultella planticola possess histidine decarboxylase (HDC), which converts histidine into histamine. Histamine fish poisoning (HFP) is attributable to the ingestion of fish containing high levels of histamine produced by HPB. Because freezing greatly decreases the histamine-producing ability of HPB, especially of P. phosphoreum, it has been speculated that HFP is caused by HDC itself from HPB cells autolyzing during frozen storage, even when HPB survive frozen storage. Here we constructed recombinant HDCs of P. phosphoreum, Photobacterium damselae, R. planticola, and Morganella morganii and investigated the ability of HDCs to produce sufficient histamine to cause HFP. To elucidate the character of these HDCs, we examined the specific activity of each recombinant HDC at various temperatures, pH levels, and NaCl concentrations. Further, we also investigated the stability of each HDC under different conditions (in reaction buffer, tuna, and dried saury) at various temperatures. P. damselae HDC readily produced sufficient histamine to cause HFP in fish samples. We consider that if HDC is implicated as an independent cause of HFP in frozen-thawed fish, the most likely causative agent is HDC of P. damselae.Histamine fish poisoning (HFP) is a food-borne chemical intoxication caused by the ingestion of histidine-rich scombroid fish such as tuna, bonito, and mackerel in which histamine-producing bacteria (HPB) produce a large amount of histamine (1,22). HPB isolated from fish implicated in actual HFP incidents reported to date include Raoultella planticola, Morganella morganii, Hafnia alvei, and Photobacterium phosphoreum (11,15). Enteric bacteria such as R. planticola and M. morganii are reported to be the dominant HPB in fish, whereas P. phosphoreum and Photobacterium damselae are frequently isolated from fish subjected to appropriate examination for marine bacteria, such as by the addition of NaCl to the culture medium and avoidance of exposure of the bacterium to high temperatures (11,16,17). The former is a psychrotrophic bacterium in the marine environment which has greater histamine-producing activity than enteric bacteria at low temperatures (11). The latter is also a prolific HPB but a mesophilic marine bacterium (13).It has been shown that accumulation of histamine by HPB occurs after the level of bacterial growth exceeds 10 7 CFU/ml in culture medium (19). Viable cell counts of P. phosphoreum and R. planticola have been reported to decrease during frozen storage (2,8). Moreover, the histidine-producing capability of HPB decreases due to injury from freezing, even if the HPB survive frozen storage (6, 21). Tuna, a scombroid fish frequently implicated in HFP, is commonly frozen during fishing and distribution (3). Other scombroid fish are also frequently frozen in current practice. These factors have led to speculation that the accumulation of histamine in thawed fish arises from the release of histidine decarboxylase (HDC) from the autol...

We investigated the prevalence of Shiga toxin-producing Escherichia coli (STEC) in hospitalized diarrhea patients in Calcutta, India, as well as in healthy domestic cattle and raw beef samples collected from the city's abattoir. Multiplex polymerase chain reaction using primers specific for stx1 and stx2 detected STEC in 18% of cow stool samples, 50% of raw beef samples, and 1.4% and 0.6% of bloody and watery stool samples, respectively, from hospitalized diarrhea patients. Various virulence genes in the STEC isolates indicated that stx1 allele predominated. Plasmid-borne markers, namely, hlyA, katP, espP, and etpD, were also identified. Bead enzyme-linked immunosorbent assay and Vero cell assay were performed to detect and evaluate the cytotoxic effect of the Shiga toxins produced by the strains. STEC is not an important cause of diarrhea in India; however, its presence in domestic cattle and beef samples suggests that this enteropathogen may become a major public health problem in the future.

A multiplex PCR assay has been developed for the identification of the six common Campylobacter taxa associated with human gastroenteritis and/or septicaemia, namely Campylobacter coli, Campylobacter fetus, Campylobacter hyointestinalis subsp. hyointestinalis, Campylobacter jejuni, Campylobacter lari and Campylobacter upsaliensis. The assay was developed using a combination of newly designed and published primers. It provided a specific PCR product for each of the five Campylobacter species and the one subspecies, and each of the PCR products was sufficiently distinguished by a difference in size by agarose gel electrophoresis. On evaluation of efficacy with 142 Campylobacter strains, the assay correctly identified all strains as 1 of the 6 Campylobacter taxa. This multiplex PCR assay is a rapid, simple and practical tool for identification of the six Campylobacter taxa commonly associated with gastroenteritis and/or septicaemia in humans, and offers an effective alternative to conventional biochemical-based assays.

Two epidemics of water-borne diarrhoeal disease involving a total of 1000 persons are reported. In both epidemics, none of the usual bacterial entero-pathogens were recognized and Plesiomonas shigelloides was the only suspect aetiological agent isolated. The ecology of P. shigelloides was investigated in these outbreaks. It was recognized as an inhabitant of fresh surface water and its presence was closely related to warm weather.