Characterization of the virulence, growth temperature and antibiotic resistance of the Campylobacter jejuni IAL 2383 strain isolated from humans

The objective of this study was to characterize the C. jejuni IAL2383 strain isolated from humans in Brazil. Transcripts for the racR, dnaJ and ciaB genes were found and flaA, plda and cadF genes were present in the genome and bacteria was sensitive to most of the important antimicrobials used to treat humans. C. jejuni IAL2383 is a good experimental model to analyze the interactions with cells.

Effect of refrigeration and frozen storage on the campylobacter jejuni recovery from naturally contaminated broiler carcasses

Campylobacter jejuni is the most common thermophilic Campylobacter associated with human enteritis in many countries. Broilers and their by-products are the main sources for human enteritis. Refrigeration and freezing are used to control bacterial growth in foods. The effect of these interventions on survival of Campylobacter jejuni is yet not quite understood. This study evaluated the effect of storage temperature on the survival of C. jejuni in chicken meat stored for seven days at 4ºC and for 28 days at -20ºC. The influence of selective enrichment on recovery of Campylobacter was also evaluated. Thirty fresh chicken meat samples were analyzed and 93.3 percent was contaminated with termotolerant Campylobacter spp. with average count of 3.08 Log10 CFU/g on direct plating. After refrigeration, 53.3 percent of the analyzed samples tested positive for Campylobacter and the average count was 1.19 Log10 CFU/g. After storage at -20ºC, 36.6 percent of the samples were positive with a verage count of 0.75 Log10 CFU/g. C. jejuni was detected after enrichment, respectively, in 50 percent of the fresh, 36.7 percent of the refrigerated and 33.3 percent of the frozen meat samples analyzed. No difference was detected for the recovery of C. jejuni from fresh, refrigerated or frozen samples after selective enrichment, showing that this microorganism can survive under the tested storage conditions.

Estudio de sobrevida y cultivo de células cocoides en cepas de: Campylobacter jejuni / A survival and culture study of cocoid cells in Campylobacter jejuni strains

Campylobacter jejuni, uno de los principales agentes causales de síndrome diarreico en seres humanos, es una bacteria que a bajas temperaturas y en condiciones de estrés forma células cocoides no cultivables. Para determinar las condiciones en las que cepas de C. jejuni se conserven viables y cultivables independiente de la morfología, se sometió a dos cepas de este a tres diversas condiciones de laboratorio evaluando morfología mediante tinción de Gram, viabilidad celular mediante pruebas bioquímicas y Citometría de Flujo. Ambas cepas lograron mantenerse viables y cultivables en dichas condiciones, tanto en la forma bacilar como en la cocoide, siendo la condición mas desfavorable para ambas cepas la temperatura ambiente (sobrevida de 4 días y 6 días), y mas favorable la bolsa hermética a 4° C (15 Y 22 días de sobrevida). La citometría de flujo resulto ser una buena herramienta para medir viabilidad de las cepas ensayadas, mostrando que las células cocoides presentaban alteraciones en la continuidad de su membrana, indicativo de perdida de viabilidad celular.

Campylobacter jejuni, a major causative agent of diarrhoeal syndrome in humans, is a bacterium that at low temperatures and under conditions of stress, coccoid cells form non-arable. To determine the conditions under which strains of C. jejuni is kept viable and cultivable, independent of the morphology, underwent two strains of C. jejuni three different laboratory conditions, and morphology was assessed by Gram stain, and cell viability by biochemical tests and flow cytometry. Both strains were able to remain viable and culturable in the three laboratory conditions, both in the form of bacilli in the coccoid form, being the most unfavourable condition for both strains, room temperature (survival of 4 days and 6 days), and the most favourable airtight bag 4 0 C (75 and 22 days of survival). The flow cytometry proved to be a good tool for measuring viability of the strains tested, showing that cells coccoid, showed alterations in the continuity of its membrane, indicative of loss of cell viability.

Better preservation of Campylobacter jejuni/C. coli in a defined medium.

Campylobacter jejuni and C. coli strains were preserved at -10 degrees C in different stock media to determine their efficacy to preserve the organism for a longer period of time. An improved defined stock culture medium was developed for the organism by removal and effective neutralisation of the toxic metabolites. Comparative study revealed that phosphate buffer saline (PBS), pH 6.7 supplemented with 0.2 per cent charcoal, 0.025 per cent FBP (ferrous sulphate, sodium metabisulphate and sodium pyruvate), 0.1 per cent L-cystein and 10 per cent glycerol could support survival of C. jejuni coli strains for as long as 135 days at -10 degrees C followed by George's medium, brucella broth with 15 per cent glycerol, fetal calf serum with 50 per cent TSYB (tryplicase soy yeast-broth) and glycerol transport broth respectively.