Cervical lymphadenitis in guinea pigs: infection via intact ocular and nasal mucosa by Streptococcus zooepidemicus.

The traditional view regarding the pathogenesis of cervical lymphadenitis in guinea pigs is that Lancefield Group C Streptococcus gains access to cervical lymph nodes via an abraded oral mucosa. In this study, it is established that inoculation of intact nasal and conjunctival mucous membranes with Streptococcus zooepidemicus (Lancefield Group C) also can produce the disease. Weanling (SPF) guinea pigs (Cavia porcellus) were divided into two experimental groups of 10 and two control groups of four each. Guinea pigs from each group were individually housed in separate cubicles. Group I was inoculated with 0.05 ml of culture containing 2.8 x 10(7) CFU/ml of S. zooepidemicus into the conjunctiva of the left eye. Group II received a similar inoculum into the left nares. Control groups received 0.05 ml of TSB broth in the same sites. Five of ten guinea pigs in Group II died four to nine days postinoculation. Surviving guinea pigs were euthanatized at intervals between days 4-13 postinoculation. All guinea pigs were necropsied, cultured and examined for evidence of infection. S. zooepidemicus was recovered from 30/50 and 39/46 sites cultured from Groups I and II, respectively. Lymphadenitis was found in cervical lymph nodes from 8/10 guinea pigs in Group I and 10/10 in Group II. The conjunctival and nasal mucosa, therefore, represent potential sites of entry resulting in cervical lymphadenitis in guinea pigs.

Campylobacter jejuni/coli in commercially reared beagles: prevalence and serotypes.

A 5 year longitudinal study involving 187 commercially reared beagles from three suppliers was undertaken to determine prevalence and serotypes of Campylobacter jejuni and C. coli. Campylobacter jejuni or C. coli was isolated from the feces in 62 of 177 asymptomatic beagles and 8 of 10 dogs with diarrhea for an overall prevalence of 37%. A total of 36 isolates were serotyped on the basis of thermostable antigens with 20 antisera prepared against frequently occurring serotypes isolated from humans with campylobacter associated enteritis (15 C. jejuni, 5 C. coli serotypes). Of these isolates, 17 (47%) serotyped with antisera to 7 C. jejuni serotypes frequently isolated in human cases of enteric campylobacteriosis (serotypes 1, 4, 10, 16, 18, 19, 37). One C. coli reacted to antisera 24, 34, 37, one strain of C. coli to antisera type 37, and another C. coli to antisera type 34. All three C. coli belonged to serotypes frequently encountered in diarrheic human patients.

Campylobacter jejuni infection in the ferret: an animal model of human campylobacteriosis.

Campylobacter infection in weanling ferrets (Mustela putorius furo) was studied as an animal model for enteric campylobacteriosis in persons. The screening of fecal cultures on selective campylobacter media showed that Campylobacter jejuni/coli was not present in the normal enteric flora. Intragastric feeding of a mixture of cat feed and 2.5 X 10(8) C jejuni isolated from ferrets with naturally occurring proliferative colitis was accomplished. All ferrets (n = 8) became infected on 3 days after they were inoculated, and at 5 to 7 days, they had bile-tinged, liquid feces with excessive mucus and blood. Ferrets gradually recovered from the diarrhea, and feces were normal 10 to 14 days after inoculation was done. Feces contained C jejuni at 14, 23, 28, 39, 46, 60, 91, 101, 109 and 144 days. In the second experiment, weanling ferrets initially were treated with 10% sodium bicarbonate, and 1 X 10(10) C jejuni organisms were administered in the cat feed. Diarrhea with fecal leukocytes and occult blood with occasional mucus appeared in almost all of the 21 ferrets from days 4 through 7. Campylobacter jejuni was isolated from the blood of 11 ferrets between 3 hours and 14 days after they were inoculated. Campylobacter jejuni bactericidal antibodies were present in serum samples at 14 days, with titers of 1:16 to 1:32. Intestinal lesions including cellular infiltration with mononuclear and polymorphonuclear leukocytes were in the lamina propria of the pyloric mucosa and small intestine of infected and control ferrets. The colon of 3 infected ferrets had small focal infiltrates of neutrophils on the lamina propria; one ferret had perivascular cuffing.(ABSTRACT TRUNCATED AT 250 WORDS)

The pathogenicity of Salmonella mbandaka in specific pathogen free rabbits.

Salmonella mbandaka was isolated from the lungs of three rabbits that developed a peracute disease and died three to eight weeks following extensive experimental manipulation. To examine the pathogenicity of this rare serotype, clinically normal, S. mbandaka-carrier rabbits were subjected to either corticosteroid immunosuppression alone or corticosteroid immunosuppression with a minor surgical procedure. Acute or peracute salmonellosis developed in one of two rabbits immunosuppressed only, and in three of four rabbits immunosuppressed and surgically manipulated. Stressful experimental procedures may precipitate episodes of clinical salmonellosis in rabbits harboring this organism. Salmonella mbandaka, should be considered a zoonotic agent in the laboratory environment.

Antibiotic sensitivity patterns of Campylobacter jejuni/coli isolated from laboratory animals and pets.

Fifty-four strains of Campylobacter jejuni/coli isolated from a variety of species of laboratory animals as well as pet dogs were tested by an agar dilution technique for susceptibility to each of 12 antimicrobial agents. Gentamicin and furazolidone were the most active of the drugs examined. The strains tested frequently were sensitive to two other aminoglycoside antibiotics, neomycin and kanamycin. Erythromycin also was effective at levels achievable in serum except in three strains which were resistant. Doxycycline and chloramphenicol were active against most strains, with 51 (96%) being susceptible to 8 micrograms/ml. The minimal inhibitory concentrations were high for penicillin, ampicillin, tetracycline, metronidazole, and sulfadimethoxine.

Campylobacter jejuni associated diarrhea in commercially reared beagles.

Campylobacter jejuni was isolated from nine of ten (90%) juvenile beagles with diarrhea, compared with an isolation rate of five of eight (63%) from beagles which remained asymptomatic during the 2 month study. In four dogs, the diarrhea was recurrent and characterized by watery, mucoid, bile-streaked feces with occasional blood. Elevated temperature and leukocytosis were noted in three of these dogs. Two dogs with diarrhea also had Giardia canis trophozoites.

An enzyme linked immunosorbent assay for detection of antibodies to Corynebacterium kutscheri in experimentally infected rats.

An enzyme-linked immunosorbent assay (ELISA) which detects rat antibody to Corynebacterium kutscheri was developed and compared with a tube agglutination assay in two infectivity studies. In four groups of rats inoculated intratracheally with 100-fold dilutions of Corynebacterium kutscheri , mortality, lesions, and recovery of Corynebacterium kutscheri were confined to the two highest dose groups. Five of 17 (29%) test rats seroconverted within 14 to 21 days post-inoculation as assayed by ELISA; four of these five (80%) seroconverted within 42 to 98 days post-inoculation as assayed by tube agglutination. ELISA titers were one to 16 times greater than tube agglutination titers. In 15 rats challenged intranasally with 6.9 X 10(6) Corynebacterium kutscheri , clinical signs were observed in one of 15 (6.7%), and bacteriologic and histopathologic evaluations detected exposure to Corynebacterium kutscheri in three of 14 (21.4%) and one of 14 (7.1%) of the rats, respectively. Fourteen days post-inoculation, seroconversion was observed in 14 of 15 (93.3%) by ELISA, as compared to six of 15 (40%) by tube agglutination (p less than 0.001). The ELISA was more sensitive than tube agglutination through 21 days post-inoculation, while sera assayed 33 to 53 days post-inoculation had comparable titers in both assays. Specificity studies using four other Corynebacterium sp indicated that the Corynebacterium kutscheri ELISA cross reacted with two of four (50%) sets of corynebacterial antisera (Corynebacterium ulcerans and Corynebacterium equi) prepared in rats, whereas no cross reactivity was observed by tube agglutination.

Mastitis caused by hemolytic Escherichia coli in the ferret.

Hemolytic Escherichia coli was isolated from the mammary glands of 8 ferrets with gangrenous mastitis. Clinical signs included firm swelling of one or more mammary glands and discoloration of the overlying skin. Peracute disease and acute septicemia were observed, and in some cases the animals rapidly became moribund. Antibiotic therapy alone did not alter the course of the disease. Wide surgical resection of the involved glands in combination with systemic antibiotic therapy (ampicillin 10 mg/kg, BID, and gentamicin 5 mg/kg, SID) was the most successful treatment. Histopathologic changes included extensive edema, hemorrhage, and necrosis, with a mixed leukocytic infiltrate and large numbers of bacteria. The agent of this disease was isolated from rectal swab specimens from clinically normal ferrets as well as ferrets that had mastitis.

Ferret as a potential reservoir for human campylobacteriosis.

A survey was conducted to determine the frequency of Campylobacter fetus subsp jejuni in feces of ferrets purchased for use in biomedical research. Over a 12-month period, 168 ferrets from 2 commercial breeders were examined by bacteriologic cultural procedures for Campylobacter spp; 61% were culturally positive for C fetus subsp jejuni. In a therapeutic trial with 16 ferrets shedding C fetus subsp jejuni in feces, erythromycin given orally failed to eliminate intestinal carriage of the organism in 15 of the animals.

Proliferative colitis in ferrets.

During a 4-month period, 31 of 156 ferrets (Mustela putorius) in a biomedical research program developed protracted diarrhea. Clinical signs were green mucohemorrhagic fecal material, partially prolapsed rectum, anorexia, body weight loss, and dehydration. Nine of the affected animals were necropsied. On gross examination, the descending colon was grossly thick and histologically characterized by marked proliferation of the mucosa, relatively few goblet cells, mixed inflammatory cell infiltrate, and penetration of the mucosal glands through the muscularis mucosa into the submucosa and tunica muscularis. Campylobacter fetus subsp jejuni was isolated from 6 of 9 ferrets with proliferative colitis. Warthin-Starry stained sections of hyperplastic colon revealed large numbers of organisms in the apical portion of epithelial cells, and organisms similar to Campylobacter spp were observed by electron microscopy in hyperplastic colonic epithelium. The proliferative colitis in the ferret is compared with the pathologic and bacterial features of similar intestinal proliferative diseases in swine and hamsters.

Isolation of Pasteurella ureae from reproductive tracts of congenic mice.

Infertility noted in two congenic strains of mice was associated with abortion, metritis, and stillbirths. Pasteurella pneumotropica was recovered from affected uterine tracts of ATL mice. Tetracycline treatment for 6 weeks was instituted in an attempt to minimize Pasteurella-associated infertility. Nine ATL mice and 12 ATH mice were examined 4 and 12 months after cessation of tetracycline therapy, respectively. Histopathologically, all animals appeared normal. P. pneumotropica was recovered from six of nine prepuces of both ATH and ATL mice; similarly, two of three vaginal culture of the ATL mice yielded this bacterium. Pasteurella ureae was isolated from three of eight reproductive tracts of the female ATH mice, Negative indole and ornithine decarboxylase reactions and positive acid production for mannitol differentiated P. ureae from P. pneumotropica. This report represents the first confirmed isolation of P. urea from animals. Biochemical profiles of atypical strains of P. pneumotropica isolated from animals are discussed and compared with those of P. ureae. The need for careful biochemical characterization of all Pasteurella isolated from rodents is emphasized.