RESUMEN
In October 1998, the Centers for Disease Control and Prevention (CDC) assisted in an investigation of an outbreak of campylobacteriosis at a school in Salina, Kansas. Twenty-two isolates were submitted from the Kansas state public health laboratory to CDC, 9 associated with the outbreak and 13 epidemiologically unrelated sporadic isolates. Pulsed-field gel electrophoresis (PFGE) using SmaI and SalI was initially used to validate the epidemiologic data. We then tested the ability of other subtyping techniques to distinguish the outbreak-associated isolates from unrelated sporadic isolates. The methods employed were somatic O serotyping, PCR-restriction fragment length polymorphism (RFLP) analysis of flaA, DNA sequence analysis of 582 bp of flaA that included the short variable region (SVR), and sequencing of the entire flaA gene. PFGE was the most discriminatory technique, yielding 11 SmaI and 10 SalI restriction profiles. All outbreak isolates were indistinguishable by PFGE, somatic O serotyping, and sequencing of the 582-bp region of the flaA gene. fla typing by PCR-RFLP grouped one sporadic isolate with the outbreak strain. Analysis of the DNA sequence of a 582-bp segment of flaA produced strain groupings similar to that generated by PCR-RFLP but further differentiated two flaA PCR-RFLP types (with a 1-bp difference in the 582-bp region). Two sporadic strains were distinct by flaA PCR-RFLP but differed only by a single base substitution in the 582-bp region. The entire flaA gene was sequenced from strains differing by a single base pair in the 582-bp region, and the data revealed that additional discrimination may in some cases be obtained by sequencing outside the SVR. PFGE was superior to all other typing methods tested for strain discrimination; it was crucial for understanding the Kansas outbreak and, when SmaI was used, provided adequate discrimination between unrelated isolates.
Asunto(s)
Técnicas de Tipificación Bacteriana/métodos , Infecciones por Campylobacter/epidemiología , Campylobacter jejuni/clasificación , Brotes de Enfermedades , Manipulación de Alimentos , Infecciones por Campylobacter/microbiología , Campylobacter jejuni/genética , Niño , ADN Bacteriano/análisis , ADN Bacteriano/genética , Electroforesis en Gel de Campo Pulsado , Flagelina/genética , Microbiología de Alimentos , Genes Bacterianos , Humanos , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa , Polimorfismo de Longitud del Fragmento de Restricción , Análisis de Secuencia de ADN , SerotipificaciónRESUMEN
In October 1995, an outbreak of Yersinia enterocolitica O:8 infections occurred in the Upper Valley of Vermont and New Hampshire. Ten patients were identified, median age 9 years (range, 6 months-44 years). Three patients were hospitalized; 1 underwent an appendectomy. Consumption of bottled pasteurized milk from a local dairy was associated with illness (matched odds ratio undefined; lower 95% confidence interval, 1.9). No deficiencies in pasteurization procedures or equipment were detected. Y. enterocolitica O:8 was isolated from 1 raw-milk sample and from a fecal sample from 1 dairy pig. The route of contamination was not determined; this outbreak likely resulted from postpasteurization contamination of milk. Dairy pigs were the most likely source of contamination. Milk bottles were likely contaminated by rinsing with untreated well water prior to filling or by other environmental routes. Educating dairy owners about Y. enterocolitica and postpasteurization contamination is necessary to prevent further outbreaks.
Asunto(s)
Brotes de Enfermedades , Leche/microbiología , Yersiniosis/epidemiología , Yersinia enterocolitica , Adolescente , Adulto , Animales , Animales Domésticos/microbiología , Estudios de Casos y Controles , Niño , Preescolar , Heces/microbiología , Femenino , Humanos , Lactante , Carne/microbiología , New Hampshire/epidemiología , Porcinos , Vermont/epidemiología , Microbiología del Agua , Abastecimiento de Agua , Yersiniosis/etiología , Yersinia enterocolitica/aislamiento & purificaciónRESUMEN
Lines of mice have been developed in our laboratory by divergent long-term selection for body fat content. This has resulted in a fivefold (23% vs 4%) higher fat percentage in the Fat line at 14 weeks of age, with little difference between the Fat and Lean lines in fat-free body weight. As part of an approach to characterize the physiological mechanisms underlying these different phenotypes, neuropeptide Y (NPY) mRNA levels in the hypothalamus and cerebral cortex of ad libitum-fed and fasted mice of the Fat and Lean selected lines were measured. Significant differences in NPY gene expression were confined to the hypothalamus. Under ad libitum-fed conditions, hypothalamic NPY mRNA levels did not differ significantly between the Fat and Lean lines. After an overnight fast of 18-20 h, hypothalamic NPY mRNA levels were increased significantly (P<0.05) by 31% in Lean animals relative to fed mice from the same line. However, fasting did not significantly stimulate NPY gene expression in the Fat line. Most plasma leptin measurements in the Lean line fell below the sensitivity threshold of the assay (0.1 ng/ml), but levels in the Fat line were at least 30 to 50 times higher under fasted and fed conditions respectively. After fasting, plasma leptin levels in the Fat line decreased significantly (P<0. 05) by 48%. Thus, unlike the situation in other rodent models, obesity in the Fat line is not associated with increased hypothalamic NPY mRNA levels in the ad libitum-fed state. The decreased sensitivity of hypothalamic NPY gene expression to fasting in the Fat line is consistent with an inhibitory effect of higher circulating leptin levels.
Asunto(s)
Tejido Adiposo/metabolismo , Neuropéptido Y/genética , Selección Genética , Animales , Composición Corporal/genética , Peso Corporal/genética , Femenino , Expresión Génica , Variación Genética , Leptina , Masculino , Ratones , Ratones Endogámicos CBA , Ratones Endogámicos , Obesidad/genética , Proteínas/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Factores de TiempoRESUMEN
To determine whether GM1-like epitopes in Campylobacter species are specific to O serotypes associated with Guillain-Barré syndrome (GBS) or whether they are frequent among random Campylobacter isolates causing enteritis, 275 random enteritis-associated isolates of Campylobacter jejuni were analyzed. To determine whether GM1-like epitopes in Campylobacter species are specific to O serotypes associated with Guillan-Barre syndrome (GBS) or whether they are frequent among random Campylobacter isolates causing enteritis, 275 enteritis-associated isolates, randomly collected in the United States, were analyzed using a cholera-toxin binding assay [corrected]. Overall, 26.2% of the isolates were positive for the GM1-like epitope. Of the 36 different O serotypes in the sample, 21 (58.3%) contained no strains positive for GM1, whereas in 6 serotypes (16.7%), >50% of isolates were positive for GM1. GBS-associated serotypes were more likely to contain strains positive for GM1 than were non-GBS-associated serotypes (37.8% vs. 15.1%, P=.0116). The results suggest that humans are frequently exposed to strains exhibiting GM1-like mimicry and, while certain serotypes may be more likely to possess GM1-like epitopes, the presence of GM1-like epitopes on Campylobacter strains does not itself trigger GBS.
Asunto(s)
Infecciones por Campylobacter/microbiología , Campylobacter jejuni/inmunología , Gangliósido G(M1)/inmunología , Lipopolisacáridos/inmunología , Imitación Molecular , Infecciones por Campylobacter/complicaciones , Campylobacter jejuni/clasificación , Campylobacter jejuni/aislamiento & purificación , Toxina del Cólera/metabolismo , Cromatografía en Capa Delgada , Diarrea/microbiología , Epítopos/inmunología , Humanos , Lipopolisacáridos/metabolismo , Polirradiculoneuropatía/microbiología , Serotipificación , Estados UnidosRESUMEN
We report a foodborne outbreak of Campylobacter jejuni infection in a summer camp. Outbreak-related cases occurred in 79 persons including 3 secondary cases in campers. Campylobacter jejuni was isolated from stool specimens from 16 of 21 patients who submitted a sample; 13 viable isolates were serotyped and all were serotype O:33 (somatic O scheme) or HL:18 (heat-labile scheme), and biotype III (Lior scheme). This serotype is widely distributed geographically but rarely isolated from humans. Samples of water from the wells supplying the camp were negative for faecal coliforms, and raw milk had not been served in the camp. A matched (1:1) case-control study identified tuna salad served for lunch on 19 July as the likely food item associated with illness (matched odds ratio=22; 95% confidence intervals (CI)=3.6-908). Swimming in the camp pool and other recreational water use in area lakes by the campers were not statistically associated with illness. The precise mechanism of introduction of the organism into the tuna salad remains unknown; contamination most likely occurred through cross-contamination with another food product, the hands of a food handler, or a work surface. Several deficiencies in the operation of the camp kitchen were identified. In Wisconsin, kitchens of such camps are subject to different inspection rules than restaurants. Camp staff, administrators, counselors, food managers, and infirmary staff, should fulfil important roles in their respective areas to prevent future outbreaks.
Asunto(s)
Infecciones por Campylobacter/epidemiología , Campylobacter jejuni/patogenicidad , Brotes de Enfermedades , Conservación de Alimentos , Atún/microbiología , Adolescente , Animales , Campylobacter jejuni/genética , Femenino , Contaminación de Alimentos , Humanos , Masculino , SerotipificaciónRESUMEN
Restriction fragment length polymorphism analysis of a PCR-amplified DNA fragment of the gene coding for 16S rRNA was performed on 148 previously characterized strains of Campylobacter, Helicobacter, Arcobacter, and Wolinella succinogenes and 13 Campylobacter-like isolates. These strains included clinical, animal, and environmental isolates. PCR amplification generated a 283-bp fragment from all species. The amplicon from each strain was digested with six restriction endonucleases (AccI, AvaI, DdeI, HaeIII, HpaII, XhoI). DdeI was useful for the initial grouping of the strains. Additional discrimination within the different DdeI groups was obtained with AccI, HaeIII, HpaII, and XhoI digestions. The PCR-restriction fragment length polymorphism analysis allowed for the discrimination of members of the genus Campylobacter from members of closely related genera and discrimination between Campylobacter species. The proposed method is simple and rapid and can be useful for the routine identification of Campylobacter-like organisms in clinical or epidemiologic studies.
Asunto(s)
Campylobacter/genética , Genes Bacterianos , Reacción en Cadena de la Polimerasa/métodos , Polimorfismo de Longitud del Fragmento de Restricción , ARN Bacteriano/genética , ARN Ribosómico 16S/genética , Animales , Secuencia de Bases , Campylobacter/clasificación , Campylobacter/aislamiento & purificación , Cartilla de ADN/genética , ADN Bacteriano/genética , Estudios de Evaluación como Asunto , Helicobacter/genética , Humanos , Datos de Secuencia Molecular , Especificidad de la Especie , Wolinella/genéticaRESUMEN
A disk method for hippurate hydrolysis was compared with the ninhydrin tube method by using 140 genetically confirmed Campylobacter strains. Results were similar for 129 (92%) strains when the inoculum size for the disk method was standardized. Six strains (4.2%) showed variable results by each method. Our results conflict with those obtained in studies by others, who found the two methods to be dissimilar.
Asunto(s)
Técnicas Bacteriológicas , Campylobacter/metabolismo , Hipuratos/metabolismo , Animales , Técnicas Bacteriológicas/normas , Campylobacter/clasificación , Campylobacter/genética , Estudios de Evaluación como Asunto , Humanos , Hidrólisis , Ninhidrina , Fenotipo , Especificidad de la EspecieRESUMEN
A PCR method for rapid identification of Campylobacter fetus subsp. fetus was evaluated. A fragment of the gene coding for 16S rRNA was amplified from crude cell lysates of 18 C. fetus strains and 30 strains representing other Campylobacter species and subspecies. The amplicons were probed by dot blot hybridization with a digoxigenin-labeled C. fetus-specific oligonucleotide probe. The probe reacted only with C. fetus subsp. fetus and C. fetus subsp. venerealis and may be useful for rapid identification in clinical laboratories.
Asunto(s)
Técnicas Bacteriológicas , Campylobacter fetus/clasificación , Campylobacter fetus/genética , Sondas de ADN , Reacción en Cadena de la Polimerasa/métodos , Técnicas Bacteriológicas/estadística & datos numéricos , Secuencia de Bases , Infecciones por Campylobacter/diagnóstico , Infecciones por Campylobacter/microbiología , Campylobacter fetus/patogenicidad , Cartilla de ADN/genética , ADN Bacteriano/genética , ADN Ribosómico/genética , Estudios de Evaluación como Asunto , Humanos , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa/estadística & datos numéricos , ARN Bacteriano/genética , ARN Ribosómico 16S/genética , Sensibilidad y EspecificidadRESUMEN
We used the scheme of Lior to biotype 140 genetically identified Campylobacter strains. Our results confirmed previous studies and extended Lior biotyping to show that nine C. jejuni subsp. doylei strains (100%) were one biotype and nine C. jejuni subsp. jejuni nalidixic acid-resistant strains (100%) were C. jejuni biotype I or II. All C. jejuni subsp. jejuni hippurate-negative strains studied and 6 of 35 C. lari strains (17%) were grouped with C. coli biotypes. These findings may be useful in epidemiologic investigations.
Asunto(s)
Técnicas de Tipificación Bacteriana , Campylobacter/clasificación , Campylobacter/genética , Animales , Campylobacter/aislamiento & purificación , Infecciones por Campylobacter/epidemiología , Infecciones por Campylobacter/microbiología , Campylobacter coli/efectos de los fármacos , Campylobacter coli/genética , Campylobacter coli/metabolismo , Campylobacter jejuni/efectos de los fármacos , Campylobacter jejuni/genética , Campylobacter jejuni/metabolismo , Farmacorresistencia Microbiana , Métodos Epidemiológicos , Estudios de Evaluación como Asunto , Hipuratos/metabolismo , Humanos , Hidrólisis , Ácido Nalidíxico/farmacologíaRESUMEN
Somatic O (formerly heat-stable) and heat-labile (HL) serotyping methods are commonly used to type Campylobacter jejuni and Campylobacter coli isolates. Although both systems are effective, the labor and time required for each have limited their application. These systems can be simplified by reducing the number of antisera used. To find an appropriate panel of antisera, we determined the distribution of common serotypes in the United States among a representative sample of 298 Campylobacter isolates. The strains, obtained between July 1989 and June 1990 from persons with sporadic cases of diarrhea, were collected from 19 randomly chosen counties in all geographic (census) regions of the United States. All strains were serotyped by the O and HL systems. By phenotypic methods, 288 C. jejuni, 9 hippurate-negative C. jejuni/C. coli, and 1 Campylobacter lari were identified. Of 57 O antisera, 24 typed 252 (84.6%) strains. Of the 55 HL antisera, 23 serotyped 253 (84.9%) strains. All strains were typeable in the unabsorbed O antisera. In the absorbed HL antisera, four strains were nontypeable and 14 were rough and untypeable. In each geographic region, 9 or more O and HL serotypes were found. Serotypes O:1, O:4, and O:13,16,43,50 and HL 1 were identified in all regions. The combination of both schemes gave greater discrimination than either system alone, but the maintenance of both requires a large resource investment. A serotyping scheme incorporating the 24 most prevalent O and 23 most prevalent HL serotypes could be useful for outbreak support and for surveillance. In the near future, we anticipate using a molecular subtyping method in combination with limited serotyping to distinguish Campylobacter strains.
Asunto(s)
Infecciones por Campylobacter/microbiología , Campylobacter/clasificación , Campylobacter/inmunología , Campylobacter/aislamiento & purificación , Infecciones por Campylobacter/epidemiología , Brotes de Enfermedades , Calor , Humanos , Antígenos O , Polisacáridos Bacterianos/inmunología , Estudios Seroepidemiológicos , Serotipificación , Estados Unidos/epidemiologíaRESUMEN
Commercial antisera for serotyping 22 heat-labile antigens of Campylobacter jejuni and Campylobacter coli were evaluated by using 66 isolates from human and nonhuman sources. Test results were compared with results of tests using antisera produced at the Centers for Disease Control (CDC), Atlanta, Ga. All strains (three isolates of each of the 22 serotypes) were typeable with the CDC antisera. Of 66 test strains, 39 (59%) were typed as the same serotype with both sets of antisera. Twenty-four strains (36%), including two heat-labile serotype reference strains, were nonreactive with the commercial antisera, and three strains (4.5%) were typed as serotypes different from those obtained with CDC antisera. Five of the 22 commercial antisera correctly serotyped all homologous strains. Our study indicated that two polyvalent antiserum pools, 7 unabsorbed antisera, and 16 absorbed monovalent antisera are weak and need modification to enhance their antibody titers. Further studies are necessary to explain the antigenic change to a different serotype in three strains.
Asunto(s)
Antígenos Bacterianos/análisis , Campylobacter coli/clasificación , Campylobacter jejuni/clasificación , Sueros Inmunes/inmunología , Serotipificación , Animales , Infecciones por Campylobacter/microbiología , Campylobacter coli/inmunología , Campylobacter jejuni/inmunología , HumanosRESUMEN
Seventy-eight aerotolerant Campylobacter isolates were characterized phenotypically and by DNA hybridization (hydroxyapatite method at 50 and 65 degrees C). Two DNA relatedness groups were found. (i) Sixty-four strains belonged to aerotolerant Campylobacter DNA hybridization group 2. These organisms were isolated from humans, primarily with diarrheal illness, and animals on several continents. Strains were aerotolerant at 30 and 36 degrees C and catalase negative or weakly catalase positive, grew in media containing glycine and on MacConkey agar, were susceptible to nalidixic acid, and were resistant to cephalothin. The name Campylobacter butzleri sp. nov. is proposed for this group. (ii) DNA hybridization group 1 consisted of the type strain of Campylobacter cryaerophila and 13 additional strains isolated from 10 animals outside the United States and from three humans within the United States. This group was genetically diverse; five strains were closely related to the type strain of C. cryaerophila (DNA hybridization group 1A), and eight strains were more closely related to one another (DNA hybridization group 1B). Strains in DNA hybridization group 1B were phenotypically diverse, with two of eight strains resembling C. cryaerophila. The seven strains from DNA hybridization groups 1A and 1B which resembled C. cryaerophila and the C. cryaerophila type strain were aerotolerant only at 30 degrees C and catalase positive, did not grow in glycine or on MacConkey agar, were generally susceptible to nalidixic acid, and were resistant to cephalothin. The remaining six strains of DNA hybridization group 1B phenotypically resembled C. butzleri; however, they were generally catalase positive and susceptible to nalidixic acid and cephalothin. DNA hybridization group 1B is not designated as a separate species at this time since it cannot, with certainty, be separated genetically from C. cryaerophila or phenotypically from C. butzleri.
Asunto(s)
Infecciones por Campylobacter/microbiología , Campylobacter/aislamiento & purificación , Diarrea/microbiología , Animales , Técnicas de Tipificación Bacteriana , Campylobacter/clasificación , Campylobacter/genética , Infecciones por Campylobacter/veterinaria , ADN Bacteriano/genética , Diarrea/veterinaria , Genotipo , Humanos , Hibridación de Ácido Nucleico , Fenotipo , Especificidad de la EspecieRESUMEN
A total of 410 well-defined Campylobacter, Helicobacter, and Wolinella strains, comprising 26 named species, subspecies, and defined groups, were tested for indoxyl acetate hydrolysis by a disk method by using disks prepared at the Centers for Disease Control, Atlanta, Ga. All C. coli (43 strains), C. cryaerophila (34 strains), C. fennelliae (5 strains), C. fennelliae-Campylobacter-like organism 3 (2 strains), C. jejuni (66 strains), C. jejuni subsp. doylei (3 strains), hippurate-negative C. jejuni-C. coli (15 strains), "C. upsaliensis" (39 strains), H. mustelae (5 strains), W. curva (1 strain), and W. recta (1 strain) hydrolyzed indoxyl acetate. Four strains gave weak positive reactions, and the remaining 196 strains, which belonged to 15 species, subspecies, and defined groups, gave negative reactions. Of the 410 study strains, 246 and 125 strains were tested for indoxyl acetate hydrolysis by a disk method and a tube method, respectively, by using commercially produced disks. The disk method, regardless of source, required less time and interpretation than the tube method did. Better differentiation between Campylobacter spp. was obtained with the indoxyl acetate test than with the trimethylamine N-oxide test. The indoxyl acetate disk distinguished C. lari from C. jejuni and C. coli, C. cinaedi from C. fennelliae, and H. pylori from H. mustelae and suggested that W. succinogenes could be differentiated from W. recta and W. curva. The indoxyl acetate disk method could be performed in 5 to 30 min, was easy to read and interpret, and should be useful as a routine diagnostic test for identification of Campylobacter spp.
Asunto(s)
Campylobacter/metabolismo , Helicobacter pylori/metabolismo , Indoles/metabolismo , Técnicas Bacteriológicas , Campylobacter/clasificación , Campylobacter/aislamiento & purificación , Infecciones por Campylobacter/diagnóstico , Estudios de Evaluación como Asunto , Infecciones por Helicobacter/diagnóstico , Helicobacter pylori/clasificación , Helicobacter pylori/aislamiento & purificación , Humanos , Hidrólisis , Especificidad de la EspecieRESUMEN
The isoprenoid quinone contents of Campylobacter cryaerophila, C. cinaedi, C. fennelliae, C. hyointestinalis, C. pylori, and "C. upsaliensis" were determined by reverse-phase thin-layer and high-performance liquid chromatography. All six of these recently named Campylobacter species contained menaquinone-6 (MK-6), but only C. hyointestinalis and "C. upsaliensis" contained 2,[5 or 8]-dimethyl-3-farnesyl-farnesyl-1,4-naphthoquinone (*MK-6), a previously described novel menaquinone of the Campylobacter genus. C. cryaerophila, C. cinaedi, C. fennelliae, and C. pylori contained an unidentified quinone (Un-MK-6) with a molecular weight of 580 and a base peak ion of m/e = 225 by mass spectrometry but with chromatographic properties different from those of MK-6. *MK-6 and Un-MK-6 are important chemotaxonomic markers of Campylobacter and Campylobacter-like organisms.
Asunto(s)
Campylobacter/análisis , Vitamina K 2/análogos & derivados , Vitamina K/análogos & derivados , Biomarcadores , Campylobacter/clasificación , Cromatografía Líquida de Alta Presión , Peso Molecular , Especificidad de la Especie , Vitamina K/análisisRESUMEN
Plasmid transformation of whole cells of Streptococcus lactis LM0230 was demonstrated. The procedure required polyethylene glycol and incubation in hypertonic media, but did not require enzymatic cell wall digestion. Conditions were optimized, yielding 5 X 10(5) transformants per micrograms of pSA3 DNA. Variables tested for effect on transformation efficiency included molecular weight, concentration, and pH of polyethylene glycol; cell density; plating media; DNA concentration; heat shock; and incubation of cells in hypertonic buffer. DNAs transformed included pSA3, pVA856, pTV1, and c2 phi. Transformation from DNA-DNA ligation mixes, with DNA not purified through density gradients, and with previously frozen cells was also achieved. The method described here for transformation of nonprotoplasted cells of LM0230 is unique, and to date has not been applied successfully to other lactic acid bacteria.
Asunto(s)
ADN Bacteriano/genética , Lactococcus lactis/genética , Plásmidos , Transformación Bacteriana , Clonación Molecular , Medios de Cultivo , ADN Bacteriano/análisis , Electroforesis en Gel de Agar , Concentración de Iones de Hidrógeno , Peso Molecular , Hibridación de Ácido Nucleico , PolietilenglicolesRESUMEN
Four cultures of a Candida sp. that lacked alpha-glucosidase activity were isolated from clinical specimens. Physiological, morphological, and serological characterizations of the yeasts and deoxyribonucleic acid reassociation studies supported their classification as a variant of C. tropicalis.