Guidelines for health and welfare monitoring of fish used in research.

The aim of this paper is to provide background material necessary for the development of international guidelines for the health and welfare monitoring of fish used in research. It provides an overview of present guidelines and discusses why more detailed and species-specific guidelines are needed. A major issue within fish research is to document the situation today and point out areas where improvements are needed.

Microbiological monitoring of laboratory mice and biocontainment in individually ventilated cages: a field study.

Over recent years, the use of individually ventilated cage (IVC) rack systems in laboratory rodent facilities has increased. Since every cage in an IVC rack may be assumed to be a separate microbiological unit, comprehensive microbiological monitoring of animals kept in IVCs has become a challenging task, which may be addressed by the appropriate use of sentinel mice. Traditionally, these sentinels have been exposed to soiled bedding but more recently, the concept of exposure to exhaust air has been considered. The work reported here was aimed firstly at testing the efficiency of a sentinel-based microbiological monitoring programme under field conditions in a quarantine unit and in a multi-user unit with frequent imports of mouse colonies from various sources. Secondly, it was aimed at determining biocontainment of naturally infected mice kept in an IVC rack, which included breeding of the mice. Sentinels were exposed both to soiled bedding and to exhaust air. The mice which were used in the study carried prevalent infectious agents encountered in research animal facilities including mouse hepatitis virus (MHV), mouse parvovirus (MPV), intestinal flagellates and pinworms. Our data indicate that the sentinel-based health monitoring programme allowed rapid detection of MHV, intestinal flagellates and pinworms investigated by a combination of soiled bedding and exhaust air exposure. MHV was also detected by exposure to exhaust air only. The IVC rack used in this study provided biocontainment when infected mice were kept together with non-infected mice in separate cages in the same IVC rack.

Shigellosis due to occupational contact with non-human primates.

A small cluster of dysenteric illness, due to Shigella flexneri, was identified among technical assistants of a primate research unit. All of the affected individuals had been in regular contact with a colony of cynomolgus macaque monkeys, one of which was known to have suffered from acute haemorrhagic colitis in the preceding few weeks. Four monkeys were found to be excreting S. flexneri bacilli of identical antigen type (1b) to that isolated from the human cases. Investigation of working practices revealed the potential for inadvertent faeco-oral spread and the need to improve existing control methods. We conclude that this small outbreak of shigellosis represents a primate-associated occupational zoonosis. The risk may not be fully appreciated by handlers or their doctors.

Pharmacokinetics of oxytetracycline in clinical cases in the red-necked wallaby (Macropus rufogriseus).

Oxytetracycline, administered at 40 mg kg-1 by intravenous injection, was used as part of the treatment of three female red-necked wallabies, Macropus rufogriseus, with suspected Fusobacterium necrophorum infections. The plasma concentrations of this drug in blood samples collected at intervals up to 24 hours after administration were measured using a biological assay. The pattern of decline in plasma oxytetracycline concentration with time was consistent with a two-compartment model. The half-life of the elimination phase was calculated to be 11.4 hours and the apparent volume of distribution was found to be 2.041 litres kg-1. These results provide a basis for devising appropriate oxytetracycline dosage regimes for the species.

Use of carbenicillin in two species of tortoise (Testudo graeca and T hermanni).

A preliminary investigation of the blood levels of carbenicillin, after the administration of a single intramuscular injection, suggests that the tortoise's bladder may act as a reservoir of antibiotic that is available for resorption. This phenomenon could confound the establishment of a safe, effective dose regime for antibiotics, in tortoises, which are excreted in an unchanged active form in urine.

Bacteriological, haematological and clinical chemical studies on the Mauritius kestrel (Falco punctatus).

Buccal and cloacal swabs and blood samples were taken from Mauritius kestrels (Falco punctatus). A number of organisms were isolated, some of which may be of relevance to the health status of this endangered species. Haematological and clinical chemical figures showed some similarities to those of other falcons but there were important discrepancies. The need to screen small populations of rare birds is emphasised.

Rhinitis in long term captive Mediterranean tortoises (Testudo graeca and T hermanii).

Rhinitis is a common condition of captive Mediterranean tortoises (Testudo species). The interpretation of the results of the bacteriological examination of naso-oropharyngeal swabs from affected individuals has proved difficult, because the normal bacterial population of this region was unknown. No substantial differences in the strains of bacteria isolated from healthy individuals and from those affected by rhinitis could be found in this study. The report that Sendai virus was implicated in the genesis of rhinitis in tortoises could not be substantiated. Paired blood samples failed to show a rise in titres against Sendai virus in either study group.

A preliminary study on the use of carbenicillin in snakes.

The results of a 10 year survey on the in vitro antibiotic resistance patterns of Pseudomonas spp. isolated from clinically ill reptiles, showed a high degree of sensitivity to carbenicillin. On the basis of sensitivity testing, carbenicillin was used to treat nine snakes of four different species, with confirmed Pseudomonas infections. Plasma carbenicillin levels were assayed, by a microbiological agar diffusion technique, at intervals of time after a single intramuscular injection at a dose rate of 400 mg/kg. Peak plasma levels of 177 and 270 micrograms/ml were reached 1 h after the initial injection and therapeutic levels persisted for at least 12 h. This initial study indicated that a suggested dose regime in snakes, derived by extrapolation from mammalian dosages, of 100-125 mg/kg daily was insufficient to produce plasma levels of sufficient magnitude and duration to effectively treat Pseudomonas infections in snakes.

Preliminary study on the use of ceftazidime, a broad spectrum cephalosporin antibiotic, in snakes.

Ceftazidime, a broad spectrum cephalosporin antibiotic with an enhanced anti-pseudomonal activity, was tested in vitro against a variety of reptilian bacterial isolates. Blood concentrations of this antibiotic were determined in clinically ill snakes following an intramuscular injection at a dose rate of 20 mg kg-1. Peak plasma levels of up to 70.5 micrograms ml-1 were reached one to eight hours after the injection and therapeutic plasma levels were maintained for at least 96 hours. A series of snakes treated with ceftazidime at a dose rate of 20 mg kg-1 every 72 hours showed a rapid and obvious clinical response to treatment. The snakes were maintained at 30 degrees C during treatment and the effect of environmental temperature on antibiotic half-life is discussed. Ceftazidime proved to be a highly active antibiotic against the bacteria known to cause disease in reptiles, with no obvious adverse effects having been so far described.

Abnormality of an index of alveolar-capillary barrier permeability associated with respiratory tract infection in the rat.

The study investigated the role of subclinical respiratory tract infection in producing an abnormality of lung function assessed by measuring an index of the permeability of the blood-gas barrier to 99mTcDTPA. Pasteurella pneumotropica was grown from throat swabs taken from 9 female rats age 10 weeks at the time of the experiment and housed under conventional husbandry conditions for 4 weeks previously. There was a significant association between the amount of bacteriological growth and an abnormality of the index of permeability. In contrast to this finding, there was no bacterial growth and no abnormality of function found in 12 female rats age 6 weeks, kept under strict barrier-maintained conditions. This finding emphasises the need for great care to be taken in the husbandry of animals used in scientific research.

Bacterial overgrowth associated with a naturally occurring enteropathy in the German shepherd dog.

Quantitative and qualitative bacteriological studies were performed on duodenal juice from 19 dogs with chronic small intestinal disease. Bacterial overgrowth was demonstrated in seven German shepherd dogs with minimal histological but specific biochemical abnormalities in the jejunal mucosa. Most frequently this overgrowth comprised bacteria of the normal flora, particularly Escherichia coli and enterococci, but these were occasionally accompanied by bacteria rarely present in the proximal small intestine of the normal dog, particularly Clostridium species. In most cases this overgrowth was associated with raised serum folate and reduced serum vitamin B12 concentrations, a finding consistent with the capacity of many enteric bacteria to synthesise folate and bind vitamin B12.

Respiratory disease associated with parainfluenza Type I (Sendai) virus in a colony of marmosets (Callithrix jacchus).

An outbreak of acute respiratory disease was observed in a colony of marmosets (Callithrix jacchus). Parainfluenza Type I (Sendai) virus was isolated from the lungs and from throat swabs of 2 animals which showed clinical signs of disease. A rising titre of serum neutralizing antibody to the virus isolated was detected in several affected animals. Approximately 50% of the colony showed clinical signs of disease, and 3 animals died. The duration of illness ranged from 3 to 16 days.

The starling (Sturnus vulgaris) as an experimental model for staphylococcal infection of the avian foot.

Inoculation of the footpad of the starling (Sturnus vulgaris) with a broth culture of Staphylococcus aureus resulted in a swelling of the foot and histological changes similar to those seen in bumblefoot in poultry and other species. In a number of cases S: aureus could be re-isolated. It is suggested that this could prove to be a useful model in the study of avian pododermatitis.

An eye infection in laboratory lizards associated with an Aeromonas sp.

Laboratory-maintained lizards (Family Lacertidae) kept for studies on thermal biology developed a superficial eye infection associated with Aeromonas liquefaciens. The origin of the infection could not be traced and attempts at therapy were generally unrewarding.

Antibody levels in mothers colonised with group B streptococci during pregnancy and in their newborn infants, as measured by an enzyme linked immunosorbent assay.

An enzyme-linked immunosorbent assay (ELISA) was developed to measure serum antibodies to group B streptococci in 20 healthy pregnant women before delivery and in their newborn infants. The sera from 10 of these women who were colonised with group B streptococci and umbilical cord sera from their infants, had higher levels of type-specific IgG antibody than the 10 non-colonised controls and their neonates. All the babies remained well. The results demonstrate that infants from colonised mothers receive type-specific antibody. The possibility that this antibody may provide some degree of protection at birth against this potentially lethal organism warrants investigation.

Genital flora during pregnancy and colonization of the newborn.

A longitudinal study of the cervical and vaginal microflora of 131 pregnant women showed a similar range of organisms at first visit (up to 16 weeks), at 28 weeks and at 36 weeks of pregnancy. Twenty different groups or genera of microorganisms were recovered, predominantly lactobacilli. There was a fall in the isolation rate of organisms in the mothers 6 to 8 weeks after delivery. Lactobacilli and yeasts including Candida albicans were recovered less frequently whereas the incidence of Escherichia coli and group B streptococci increased.Infants born to these mothers were swabbed within 24 hours of delivery and yielded organisms from the umbilicus, ear and mouth in 24%, 33% and 38% of cases respectively. Alpha haemolytic streptococci and Staphylococcus aureus were the predominant organisms. Sixteen different groups or genera were isolated.The isolation rates in non-pregnant women attending a `well-women' clinic were similar to those in the postnatal mothers; few women of 60 years or more were colonized.