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On the microbiological diagnostics of Campylobacter jejuni
Abstract:
Investigation of campylobacteriosis cases in 1983-1989 resulted in the isolation of a total of 245 antigenically identified and 23 unidentified strains from humans, animals and foods. A commonly accepted method developed in 1985 using our own experience was used for strain isolation and culturing. A variety of nutrient media in combination with different supplementary substances (antibiotics, growth factors) and additives, such as horse serum, were verified as well as filtration and Fortner's procedures. The best results were obtained when material was stored in thioglycolate transport medium accompanied by cold enrichment (24 h at 4 degrees C) and repeated inoculation into appropriate solid nutrient medium. Owing to the simple culturing of C. jejuni, the number of not elucidated diarrheas was reduced and the incidence of campylobacteriosis (approximately 12 %) is higher than that of salmonellosis and shigellosis. A total of 245 C. jejuni strains was classified using Kahlich's antigenic scheme. The incidence of serovars 1 and 2 was greater than 10 %. Five serovars (13, 17, 25, 26 and 27) were represented by only one strain. The study of campylobacteriosis also revealed the long-term excretion of C. jejuni by convalescents (71 days at most) as well as the occurrence of family outbreaks. Procedures were developed to ensure short-term and long-term (freeze-drying) preservation of isolated strains. The number of cases reported by microbiological laboratories in the framework of the Hygienic Service throughout Czechoslovakia suggest an increase in positive findings with C. jejuni as the etiological agent.
Insights
This study isolated 245 Campylobacter jejuni strains, revealing serovar prevalence and long-term excretion. Improved culturing methods reduced undiagnosed diarrheal cases, highlighting campylobacteriosis as a significant public health concern.
Area of Science:
- Microbiology
- Infectious Diseases
- Food Safety
Background:
- Campylobacteriosis is a significant cause of diarrheal illness.
- Accurate identification and culturing of Campylobacter jejuni are crucial for epidemiological studies.
- Previous methods for isolating Campylobacter jejuni were suboptimal.
Purpose of the Study:
- To investigate campylobacteriosis cases between 1983-1989.
- To optimize strain isolation and culturing techniques for Campylobacter jejuni.
- To determine the antigenic profile and prevalence of Campylobacter jejuni serovars.
Main Methods:
- Isolation and culturing of bacterial strains from human, animal, and food samples.
- Verification of various nutrient media, supplementary substances, and procedures.
- Application of cold enrichment and thioglycolate transport medium for optimal results.
- Antigenic classification of isolated Campylobacter jejuni strains using Kahlich's scheme.
Main Results:
- 245 antigenically identified and 23 unidentified Campylobacter jejuni strains were isolated.
- Optimized methods involving thioglycolate transport medium and cold enrichment yielded the best results.
- Campylobacteriosis incidence (approx. 12%) was found to be higher than salmonellosis and shigellosis.
- Serovars 1 and 2 were most prevalent, each exceeding 10% incidence.
- Long-term excretion of Campylobacter jejuni (up to 71 days) and family outbreaks were observed.
Conclusions:
- The study established effective methods for Campylobacter jejuni isolation and culturing, reducing undiagnosed diarrheal cases.
- Antigenic typing revealed significant prevalence of specific serovars, aiding in epidemiological tracking.
- Findings underscore the public health importance of campylobacteriosis and the need for continued surveillance.