Thermotolerant Campylobacter Research Articles

Descriptive epidemiology of infections due to thermotolerant Campylobacter spp. in Norway, 1979–1988

This report reviews the first ten years of Campylobacter surveillance in Norway. During 1979-1988, a total of 3,545 isolates of thermotolerant Campylobacter spp. were reported. The isolation rate increased from 1.8 per 100,000 persons per year in 1979 to 13.1 in 1988. The highest isolation rate for both sexes occurred during the first five years of life (31.0 per 100,000). A smaller second peak was detected in the age group 15-24 years (11.1 per 100,000). The male-to-female ratio was 1.52:1 for infants less than five years of age, compared with a ratio of 1.35:1 for all ages combined. Thirty-eight percent of the infections had most probably been acquired abroad. The isolation rate in urban areas (12.4 per 100,000) was over twice that observed in rural agricultural municipalities (5.5 per 100,000). However, this difference was largely due to a higher proportion of imported cases in urban areas, only small variations in isolation rate were observed when imported cases were excluded. The seasonal distribution of Campylobacter isolates showed a peak during the warm months of the year. Travel activity during summer holidays did not account for this trend, since the summer peak became even more pronounced when imported cases were excluded. A north-south gradient in the seasonality was observed; when domestic cases were considered, the summer peak became more accentuated with increasing latitude reaching a maximum in subarctic areas. This might be explained by corresponding variations in occurrence of campylobacters in surface water sources.

Occurrence of thermotolerant campylobacters in fresh vegetables sold at farmers' outdoor markets and supermarkets

A total of 1564 fresh samples of 10 vegetable types from two different retail levels (533 samples from farmers' outdoor markets and 1031 samples from supermarkets) were surveyed for the occurrence of thermotolerant campylobacters. In samples from the outdoor markets, campylobacters were detected on six types of vegetables; the detection rates were spinach, 3.3; lettuce, 3.1; radish, 2.7; green onions, 2.5; parsley, 2.4; and potatoes, 1.6%. Campylobacter jejuni was the predominant species (88%), with the remainder being C. lari (8%) and C. coli (4%). When the outdoor market samples were thoroughly washed with chlorinated water, all were negative for campylobacters. Of the samples from supermarkets, all were negative for campylobacters whether purchased in summer or winter. These results suggest that vegetables sold at farmers' outdoor markets are produced and (or) stored under less sanitary conditions than those sold at supermarkets, and they could constitute health hazards. Therefore, vegetables (e.g., potatoes and spinach) from farmers' markets must be decontaminated by washing with chlorinated water or cooked thoroughly before consumption.

Survey of thermotolerant Campylobacter spp. and Yersinia spp. in three surface water sources in Norway

We investigated the occurrence of thermotolerant Campylobacter and Yersinia spp. in three surface water sources in Norway which represented different levels of pollution andtrophication. Samples were collected every fortnight during a 14-month period. In addition, samples from 100 private wells were examined for campylobacters only. Campylobacter was recovered from 42 (43.8%) of the 96 samples of surface water, whereas Yersinia spp. were isolated from four(4.2%) of the samples. Campylobacter was not isolated from the well water samples. The highest isolation rate of Campylobacter was obtained from the two most polluted water sources. The proportion of positive samples was significantly higher in the autumn (71.4%) than in the spring (36.4%) or summer (22.2%). The highest overall isolation rate was obtained at water temperatures ranging from 2.1 to 8.0°C, and the lowest at temperatures greater than 15°C. Logistic regression analysis showed a highly significant relationship between the prevalence of Campylobacter and the number of three types of indicator bacteria: faecal coliforms, faecal streptococci and sulphite-reducing clostridia. Of the 60 Campylobacter isolates obtained, 51.7% belonged to C. jejuni biotype 1, 20.0% belonged to jejuni biotype 2, 21.7% to C. coli, 3.3% to C. lari and 3.3% were non-typable. All four Yersinia isolates were non-pathogenic variants.

Clinical features of sporadic Campylobacter infections in Norway.

To assess risk factors and clinical impact of campylobacteriosis in Norway, a case-control study of sporadic cases of infection with thermotolerant Campylobacter spp. was conducted. This report describes: (1) the frequency and duration of signs and symptoms, antimicrobial treatment, hospitalization, and faecal carriage among the study patients; (2) diarrhoeal illness and campylobacter carriage among their household members; and (3) antimicrobial susceptibility pattern among bacterial isolates. A total of 135 patients with bacteriologically confirmed campylobacter infection were enrolled in the study. Of these, 58 (43%) were domestically acquired while 77 (57%) were acquired abroad. If the study enrollees are representative of the cases reported to the national surveillance system, the reported infections led to an estimated annual average of at least 8590 days of illness, 78 admissions to hospital, 329 days of hospital stay, 2236 days lost at work or at school, 1000 physician consultations, and 96 antimicrobial prescriptions among the 4.2 million Norwegians. Convalescent carriage of campylobacter was detected in 16% of the patients who submitted follow-up stool specimens; the organism was carried for a mean of 37.6 days (median 31, range 15-69) after the onset of illness. Antimicrobial treatment appeared to have reduced the likelihood of carriage once symptoms had resolved. Diarrhoeal illness was more commonly reported in members of case households than control households (OR = 5.44, p < 0.0001). Cases were more likely than controls to report antecedent recurrent diarrhoea (OR = 6.00, p = 0.034). Two cases of neonatal infection, probably acquired from the mother at the time of delivery, were detected.(ABSTRACT TRUNCATED AT 250 WORDS)

Campylobacter intestinal carriage among stray and pet dogs

The natural distribution of thermotolerant Campylobacter sp. in dogs (150 stray animals and 64 pets) was studied. Campylobacters were more frequently isolated (p < 0.01) from stray dogs (51.3%) rather than from pet dogs (21.9%). All the biotypes described by Lior for C. jejuni and C. coli were found among stray animals, whereas only C. jejuni biotypes I and II and C. coli biotype II were found among pet dogs. The need for more studies related to the role of environmental sanitary conditions in the spreading of Campylobacter species is noted.

Application of a Biotin-Labelled DNA Probe to Detect Campylobacter

A procedure for direct detection of Campylobacter in feces has been developed using a biotin-labelled DNA probe. A species-specific probe (Bio-pCJ174 probe) for C. jejuni and a multivalent probe (Bio-pooled probe) for the thermotolerant Campylobacter species were developed with Bio-11-dUTP. Both probes were used to detect Campylobacter in 100 specimens of chicken feces. The coincidence rate of the results obtained by the Bio-pooled probe and cultivation was 90% and that of the Bio-pCJ 174 probe and cultivation was 96%. Identification of isolates was also carried out with both probes.

Species and biotype distribution of thermotolerant campylobacters in animal reservoirs in southern Chile.

The prevalence of thermotolerant Campylobacters in mammals and birds from Southern Chile was determined. Campylobacters were isolated from 46.3% of the animals studied being C. jejuni biotipe 1 the most frequent (25.7%) followed by C. coli (17.4%) and C. jejuni biotipe 2 (3.2%).

Comparison of media and filtration procedures for qualitative recovery of thermotolerant Campylobacter spp. from naturally contaminated surface water

Different media and filtration procedures were compared for efficiency in recovering thermotolerant campylobacters from three naturally contaminated water sources representing different turbidities and levels of contamination. Three selective enrichment broths were evaluated. Regardless of the kind of broth employed, enrichment did not significantly enhance recovery over that produced by direct plating onto both Skirrow's agar and colistin-amphotericin-keflin (CAK) agar. However, enrichment was clearly advantageous when Skirrow's agar was used as the sole plating medium. Of the four filtration procedures compared, the highest recovery was obtained with 0.45 μm Millipore membrane filters. Subsequent filtration through a 0.22 μm membrane did not increase the yield. Of the three plating media evaluated, the best overall recovery was obtained with Preston agar, followed by CAK agar, whereas Skirrow's medium was inferior. For all three agar media, incubation for 48 h greatly increased the yield as compared with 24 h incubation. We could not demonstrate any statistically significant differences between the plating media as regards their relative efficiency in isolating different Campylobacter species.

Campylobacter infection associated with raw milk. An outbreak of gastroenteritis due to Campylobacter jejuni and thermotolerant Campylobacter fetus subsp fetus.

Raw milk is identified with increasing numbers of outbreaks of gastroenteritis and is an important vehicle for transmission of Campylobacter infection. Unlike Campylobacter jejuni, Campylobacter fetus subsp fetus has not been associated with common-source outbreaks of gastroenteritis. This report describes an outbreak of gastroenteritis involving C jejuni and a thermotolerant strain of C fetus subsp fetus associated with raw milk. Fifteen (39%) of 38 persons who attended a banquet in Wisconsin in June 1982 developed acute gastroenteritis. Stool specimens were obtained from nine ill guests; four yielded C jejuni and three yielded C fetus subsp fetus. The C fetus subsp fetus isolates were identified fortuitously, in part because of unusual thermotolerance (growth at 42 degrees C), permitting isolation at temperature appropriate for C jejuni. Survey results implicated raw milk as the source of the outbreak. Findings provide evidence of a potentially emergent milkborne pathogen contributing to the risk of raw milk consumption and suggest that current diagnostic laboratory techniques may fail to identify significant foodborne agents.

Investigation of Yersinia enterocolitica, Yersinia enterocolitica-like bacteria, and thermotolerant campylobacters in Norwegian pork products

Altogether, Yersinia spp. were isolated from 41 (27.0%) of 152 samples of retail pork products. Thermotolerant campylobacters were not detected in this study. Yersinia spp. were recovered from 39 (30.7%) of the 127 raw pork samples and from two (8.0%) of the 25 cooked pork samples investigated. Sixty distinct strains were isolated. Y. enterocolitica comprised 58.3% of the total number, followed by Y. intermedia (20.0%), Y. kristensenii (18.3%), and Y. frederiksenii (3.3%). The serotyping scheme employed enabled us to type 91.7% of the strains. The most frequently isolated serotype was O:5 which comprised 20.0% of the total number, followed by O:7, 8 (11.7%), and O:11 (8.3%). Only one strain of O:3/biotype 4, the predominant human pathogen in Europe, was isolated. This was the only isolate which provoked positive reaction in the autoagglutination virulence assay. A second O:3 strain was classified as Y. kristensenii. Optimal recovery of Yersinia spp. was achieved using three-weeks cold enrichment in addition to a two-step procedure based on pre-enrichment in a low-selectivity medium (8 days, 4°C) followed by selective enrichment in modified Rappaport broth (4 days, 20–25°C). The results indicate that Yersinia spp. are more likely to be isolated from foods with a high level of coliforms than from foods with low coliform counts.

Base composition and sequence homology of deoxyribonucleic acid of thermotolerantCampylobacter from human and animal sources

A total of 31Campylobacter strains were studied. Of these, 24 were thermotolerant field isolates and 7 were reference strains. Mol% G+C was estimated by thermal denaturation and DNA-DNA-relatedness by the hydroxyapatite method. The strains identified asC. jejuni orC. coli and differentiated by the hippurate hydrolysis test formed separate, homogenous DNA homology groups. The two species were genetically more related to each other than to otherCampylobacter species. Results also show that the group of hippurate-negative thermotolerant campylobacters resistant to nalidixic acid is genetically heterogenous.