Campylobacter jejuni is a leading cause of bacterial gastroenteritis in humans, and contamination of poultry has been implicated in illness. The bacteria are fastidious in terms of their temperature requirements, being unable to grow below ca. 31°C, but have been found to be physiologically active at lower temperatures and to tolerate exposure to low temperatures in a strain-dependent manner. In this study, 19 field isolates of C. jejuni (10 of clinical and 9 of poultry origin) were studied for their ability to tolerate prolonged exposure to low temperature (4°C). Although substantial variability was found among different strains, clinical isolates tended to be significantly more likely to remain viable following cold exposure than poultry-derived strains. In contrast, the relative degree of tolerance of the bacteria to freezing at ؊20°C and freeze-thawing was strain specific but independent of strain source (poultry versus clinical) and degree of cold (4°C) tolerance.Campylobacter jejuni is currently a leading cause of bacterial gastroenteritis in humans (1,20,30). Infection by C. jejuni is also the most common antecedent to Guillain-Barré syndrome, an autoimmune disorder of the peripheral nervous system (19). C. jejuni and related campylobacters are unique among human food-borne pathogens in being obligate microaerophiles and in their narrow and rather unusual temperature range for growth. C. jejuni and other "thermophilic campylobacters" grow optimally at a relatively high temperature (42°C), but their minimal growth temperature is in the range of 31 to 36°C (3,5,8), and growth ceases abruptly around 30°C (8).C. jejuni is a commensal microbe in avian species, including poultry (13, 36), and epidemiological studies have frequently implicated raw and undercooked poultry in human campylobacteriosis (1,20,30). A substantial portion (as much as 98%) of poultry at retail is contaminated with the pathogen (1, 29). Other meat products can also be contaminated with Campylobacter and can contribute to human illness, along with untreated water, raw milk, and exposure to live birds and to pets with diarrhea (1,20).Several studies suggest that, in spite of fastidious requirements for growth, C. jejuni has the potential for remarkable survival under conditions nonpermissive to growth. In surface waters and water microcosms, survival was shown to be limited to a few days at ambient temperatures of ca. 20°C but was noticeably enhanced (up to several weeks) at 4°C (2, 22, 31). Rollins and Colwell (26) showed that at 4°C C. jejuni could survive and remain at the viable but nonculturable stage for about 4 months. Oxygen consumption, catalase activity, ATP generation, chemotaxis, and protein synthesis were also observed at 4°C (8). Furthermore, Lee et al. (15) showed that C. jejuni remained viable on raw chicken skin fragments at Ϫ20 and Ϫ70°C for 14 and 56 days, respectively. In the same study, C. jejuni was also able to persist on the chicken skin fragments at 4°C (15).The ability of C. jejuni to survive refrigeration and fr...

During 22-24 August 2004, an outbreak of Shigella sonnei infection affected air travellers who departed from Hawaii. Forty-seven passengers with culture-confirmed shigellosis and 116 probable cases who travelled on 12 flights dispersed to Japan, Australia, 22 US states, and American Samoa. All flights were served by one caterer. Pulsed-field gel electrophoresis of all 29 S. sonnei isolates yielded patterns that matched within one band. Food histories and menu reviews identified raw carrot served onboard as the likely vehicle of infection. Attack rates for diarrhoea on three surveyed flights with confirmed cases were 54% (110/204), 32% (20/63), and 12% (8/67). A total of 2700 meals were served on flights with confirmed cases; using attack rates observed on surveyed flights, we estimated that 300-1500 passengers were infected. This outbreak illustrates the risk of rapid, global spread of illness from a point-source at a major airline hub.

Listeria monocytogenes and Listeria innocua differ markedly in virulence but are indistinguishable by classical taxonomic criteria. Both species are actively motile and produce abundant flagellin at 22 degrees C. We have found, however, noticeable differences between L. monocytogenes and L. innocua in motility and flagellin production at 37 degrees C. At this temperature, L. monocytogenes strains were virtually nonmotile and produced little or no detectable flagellin, whereas strains of L. innocua were frequently motile and produced substantial amounts of flagellin. This flagellin was recognized by a Listeria genus-specific monoclonal antibody that also recognized flagellin produced at 22 degrees C. These results suggest differential regulation of flagellin production between L. monocytogenes and L. innocua at 37 degrees C.

Two clusters of necrotizing fasciitis (NF) due to group A streptococcus (GAS) were identified on the Hawaiian islands of Kauai and Maui during 1997 and 2002, respectively. The emm gene sequence types and the pulsed-field gel electrophoresis patterns were determined for 6 isolates recovered from patients with NF and for 116 isolates recovered from patients with temporally associated community-acquired GAS infection. No predominant emm type was identified, and the emm types of 64 (52.5%) of the isolates were considered to be uncommon in the continental United States. These findings suggest that unusual emm types might be responsible for invasive GAS infections in patients from Hawaii.