Large production of cholera toxin by Vibrio cholerae O1 in yeast extract peptone water

Iwanaga, Masaaki; Kuyyakanond, Thicumporn

doi:10.1128/jcm.25.12.2314-2316.1987

Cited by 44 publications

(24 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Transient transcription apparently takes place in response to the combination of static growth and culture cell density because induction occurred during the static period and at the early stationary phase. These results are in agreement with the initial physiological studies performed by Iwanaga et al, who showed that a 4-h static growth period followed by strong aeration was optimal to stimulate CT production in V. cholerae El Tor (17,18). We found that ToxR-driven transcription of toxT was initiated precisely at the h 4 yet expression was transient, continuing for only 1 h during shaking.…”

Section: Discussionsupporting

confidence: 93%

“…Strains were maintained at Ϫ70°C in LB medium containing 20% glycerol. The classical V. cholerae strain O395 was grown at 30°C in LB medium, and the V. cholerae El Tor strain E7946 was grown at 37°C in AKI medium (17) without sodium bicarbonate (18). The classical strain was used to generate a toxT primer extension product used as a reference to estimate the sizes of the toxT and ctxA primer extension products from the El Tor strain.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Transient Transcriptional Activation of the Vibrio cholerae El Tor Virulence Regulator ToxT in Response to Culture Conditions

et al. 1999

View full text Add to dashboard Cite

Vibrio cholerae El Tor require special in vitro culture conditions, consisting of an initial static growth period followed by shift to shaking (AKI conditions), for expression of cholera toxin (CT) and toxin coregulated pili (TCP). ToxT, a regulator whose initial transcription depends on the ToxR regulator, positively modulates expression of CT and TCP. To help understand control of CT and TCP in El Tor vibrios, we monitored ctxAB and ToxR-dependenttoxT transcription by time course primer extension assays. AKI conditions stimulated CT synthesis with an absence ofctxAB transcription during static growth followed by induction upon shaking. ToxR-dependent toxT transcription was induced at the end of the static growth period but was transient, stopping shortly after shaking was initiated but, interestingly, also if the static phase was prolonged. Immunoblot assays showed that ToxR protein levels were not coincidentally transient, implying a protein on/off switch mechanism for ToxR. Despite the transient activation by ToxR, transcription of ctxAB was maintained during shaking. This finding suggested continued toxT expression, possibly through relay transcription from another promoter. The 12.6-kb distant upstream tcpA promoter responsible for expression of the TCP operon has been proposed to provide an alternate toxTmessage by readthrough transcription. Activation of thetcpA promoter is supported by increased expression of TcpA protein during the shaking phase of the culture. Readthrough transcription of toxT from tcpA would be compatible with reverse transcription-PCR evidence for atoxT mRNA at times when ToxR-dependent transcription was no longer detectable by primer extension.

show abstract

Section: Discussionsupporting

confidence: 93%

Section: Methodsmentioning

confidence: 99%

Transient Transcriptional Activation of the Vibrio cholerae El Tor Virulence Regulator ToxT in Response to Culture Conditions

et al. 1999

View full text Add to dashboard Cite

show abstract

“…From the evaluation study, it was demonstrated that the bead-ELISA was more sensitive than the RPLA for detection of CT from broth cultures of strains of V. cholerae O1. It has been reported that the cultural requirements for optimal production of CT by V. cholerae O1 vary between classical and eltor biotype (4,12,13), and among strains even in the same biotype (unpublished observation). In This work was supported in part by a Grant-in-Aid for Scientific Research from the Ministry of Education, Science and Culture of Japan.…”

Section: Discussionmentioning

confidence: 96%

Detection of Cholera Toxin by a Highly Sensitive Bead‐Enzyme Linked Immunosorbent Assay

Uesaka

Otsuka

Kashida

et al. 1992

Microbiology and Immunology

View full text Add to dashboard Cite

A bead-enzyme linked immunosorbent assay (bead-ELISA) for detection and quantification of cholera toxin (CT) in broth cultures of Vibrio cholerae O1 has been developed. Under optimal buffer and pH conditions the bead-ELISA could consistently detect 40 pg/ml of CT. None of the ingredients of commonly used media for in vitro culture of V. cholerae O1 hindered the performance of the bead-ELISA. Evaluation of the sensitivity and specificity of the bead-ELISA against the commonly used reversed passive latex agglutination (RPLA) test for detection of CT was performed using a collection of 239 strains of V. cholerae O1 (including both biotypes and serotypes) which were examined by a gene probe encoding for the A1 subunit of CT. Although both the assays were highly specific, the bead-ELISA was more sensitive than the RPLA. Quantification of CT by the bead-ELISA revealed that the concentration of CT produced by the strains of V.which were negative by the RPLA was lower than 1 ng/ml and therefore below the minimum detection ability of the RPLA. The bead-ELISA is a simple, specific and highly sensitive assay for routine detection of CT and is recommended for routine use in clinical microbiology laboratories.

show abstract

“…Biochemical behaviors were examined in accordance with the routine laboratory methods used to identify V cholerae. Cholera toxin production was examined in YEP medium under AKI-SW conditions and was determined by the reversed passive latex agglutination method (2 in the culture fluid was detected using V cholerae H218 as the indicator strain (6). Drug sensitivities were examined by determination of the minimum inhibitory concentrations of polymyxin-B, erythromycin and tetracycline.…”

Section: Methodsmentioning

confidence: 99%

Molecular Epidemiology of Vibrio cholerae O1 Isolated from Sporadic Cholera Cases in Okinawa, Japan

Iwanaga

Honma

Enami

1997

Microbiology and Immunology

View full text Add to dashboard Cite

In July 1994, 6 cholera cases due to Vibrio cholerae O1 El Tor Ogawa sporadically appeared in Okinawa. All 6 patients had no history of traveling abroad. In the period of this cholera outbreak, a strain of V cholerae O1 El Tor Ogawa was detected from an imported fish at the Naha port quarantine station. The isolates were characterized to clarify whether or not, they belonged to a common clone. Phenotypes were identical except that one strain revealed cured Celebes and the others were original Celebes in kappa phage typing. The restriction fragment patterns of DNA of the isolates hybridized with an enzyme-labeled oligonucleotide probe for cholera toxin gene (ctx) were identical. Randomly amplified polymorphic DNA of the isolates were identical when a primer was used, but 2 patterns were seen when another primer was used. Pulsed-field gel electrophoresis of the chromosomal DNA digested with Notl restriction enzyme showed 3 patterns. The DNA fragment pattern of the strain isolated from the imported fish was different from the clinical isolates. These results suggested that there was no epidemiological relation among the strains of V cholerae O1 isolated during this period.Key words: Vibrio cholerae O1, Okinawa, Genotype, Epidemiology Cholera is not endemic in Japan, however, approximately 100 cases per year have been reported over the past few decades. Although most of the cases are associated with traveling abroad, some cases without any history of traveling abroad have also been seen. In July 1994, 6 cases of cholera patients sporadically appeared in Okinawa, where cholera cases have not been diagnosed for a long time. The patients in Okinawa were infected with Vibrio cholerae O1 El Tor Ogawa, and they had no history of traveling abroad. In spite of an intensive investigation, the vehicle of transmission could not be specified. V cholerae O1 El Tor Inaba has been detected in a river in Naha City but was non-toxigenic (3). Toxigenic V cholerae O1 has never been isolated from the environment of Okinawa. Toxigenic V cholerae occasionally been detected in imported marine products at the Sea Port Quarantine in Japan. Indeed, in Okinawa, toxigenic V cholerae O1 was isolated at the same time of that from the imported fish at the Naha quarantine station. In this study, the V cholerae isolates were phenotypically and genetically compared to examine a possibility that the strains were epidemiologically related. Materials and MethodsBacterial strains. Five strains of V cholerae O1 (OK-1, 2, 3, 4, 5) isolated from 4 patients during illness, and one strain (OK-11) from an imported fish at the Naha port quarantine in July 1994 were used. OK-3 and OK-4 were isolated from the same patient. Other strains of V cholerae O1 stocked in our laboratory were also used when necessary.Phenotypic characterization of the isolates. Phenotypes of the isolates were examined for biochemical behaviors, cholera toxin production, kappa phage production and drug sensitivities. Biochemical behaviors were examined in accordance with the rou...

show abstract

Large production of cholera toxin by Vibrio cholerae O1 in yeast extract peptone water

Cited by 44 publications

References 8 publications

Transient Transcriptional Activation of the Vibrio cholerae El Tor Virulence Regulator ToxT in Response to Culture Conditions

Transient Transcriptional Activation of the Vibrio cholerae El Tor Virulence Regulator ToxT in Response to Culture Conditions

Detection of Cholera Toxin by a Highly Sensitive Bead‐Enzyme Linked Immunosorbent Assay

Molecular Epidemiology of Vibrio cholerae O1 Isolated from Sporadic Cholera Cases in Okinawa, Japan

Contact Info

Product

Resources

About