The seasonality of canine births and human campylobacteriosis: a hypothesis

Campylobacters as zoonotic pathogens: a food production perspective

Campylobacters remain highly important zoonotic pathogens worldwide which infect an estimated 1% of the population of Western Europe each year. Certain campylobacters are also important in infections of animals, particularly of the reproductive tract, and some are involved in periodontal disease. This paper focuses, however, on the two species which are most important in food-borne infections of humans, Campylobacter (C.) jejuni and C. coli. Infection with these campylobacters is serious in its own right but can also have long-term sequelae such as reactive arthritis and Guillain-Barré syndrome. The pathogens are ubiquitous in nature and in domestic animals and, as a consequence, are found frequently in the environment and on many raw foods, of both plant and animal origin and bacterial numbers can be very high on certain key foods like raw poultry meat. Although all commercial poultry species can carry campylobacters, the risk is greater from chicken because of the high levels of consumption. Campylobacters are relatively 'new' zoonotic pathogens as routine culture from clinical specimens only became possible in the late 1970s. As a consequence there is much that still needs to be understood about the behaviour and pathogenicity of these highly important bacteria. In particular, and from a food industry/food safety perspective, it is important to better understand the behaviour of C. jejuni and C. coli in the food production environment, and how this affects their ability to survive certain food production processes. There is a belief that campylobacters are much more sensitive to hostile conditions than either salmonellas or Escherichia coli. Much of data to support this view have been derived from laboratory experiments and may not fully represent the natural situation. Studies are showing that campylobacters may be more robust than previously thought and thus may represent a greater challenge to food safety. We recommend that research is undertaken to better understand how campylobacters behave in the food chain and how responses to relevant conditions affect their ability to survive processing and their virulence. There is also a need to better understand the reasons why campylobacters are capable of frequent change, particularly in the expression of surface antigens.

Reproductive patterns and reproductive pathologies of stray bitches in the tropics

The objectives of this study were to determine the annual reproductive pattern and to estimate the frequency of reproductive pathologies in female mongrel stray dogs under tropical conditions. The genital tracts of 300 mongrel bitches from a municipal dog pound were examined post-mortem from January to December 2003. Season of the year, age, size, and body condition score (BCS) were recorded for each dog. The year was divided into three seasons: warm-dry (March-June), warm-humid (July-October), and fresh-humid (November-February). Distribution of estrus periods was not influenced by any of the factors studied (i.e. season, age, size, BCS). A significantly lower number of pregnancies were recorded during the warm-dry season, probably as a consequence of embryo resorption. Underweight animals had a significantly lower percentage of pregnancies than bitches of ideal BCS. More ovulations per bitch occurred during the warm-humid season than during the other seasons of the year, probably due to climatic factors. Bitches of medium and large size had more ovulations than those of small size. Of the 300 bitches examined, 43.5% had one or more genital pathologies. The most frequent pathologies found in the ovary, uterus, and vagina were epoöphoron cysts (6.7%), serosal inclusion cysts (5.0%), and transmissible venereal tumors (15.3%), but the capacity of the females to come into estrus or to become pregnant was not affected by these conditions. We concluded that stray domestic bitches in the tropics were not seasonal breeders, but their reproductive pattern was apparently modified by environmental factors such as temperature and probably photoperiod. Although several bitches in the present study had reproductive pathology, the most prevalent pathologies did not adversely reproductive capacity.

Thermotolerant Campylobacters in domestic animals in a defined population in Buenos Aires, Argentina

We assessed the prevalence of Campylobacter jejuni in animals in a region of unsatisfied basic needs in the city of Buenos Aires and studied a few risk factors. First we conducted a census to identify all dwellings having pet animals (dogs, cats, and birds). Fecal samples were then taken for isolation and identification of strains. We observed 17% prevalence for dogs (95% CI: 13, 22), 16% for cats (95% CI: 8, 27) and 19% for birds (95% CI: 5, 42). In dogs, the highest prevalences were found in summer and in animals <1 year old; in cats, in autumn and those aged 3-5 years. Strains were identified as C. jejuni biotype II in 70% of isolates. In the population described here, dogs, cats and birds kept in households were potential sources of human Campylobacter infections.