Naturally acquired infections of Klebsiella pneumoniae in Wistar rats

Abstract

357Summary Klebsiella pneumoniae was isolated from lesions in 2 dead and 82 ill animals in a breeding colony of 2300 Wistar rats. The clinical signs were unilaterial and bilateral fluctuating masses in the cervical and inguinal areas, and focal cutaneous ulcers in the ventral neck. Cervical and inguinal lymphadenitis with abscess formation were found on microscopic examination. Lesions also occurred in visceral organs. Although characteristic of the natural infection in most species, no respiratory lesions were seen in this epizootic episode. A capsular serotype 5 K. pneumoniae which did not utilize malonate was the only bacterial strain cultured from the lesions, but other K. pneumoniae strains that utilized malonate and were untypable hy capsular serology were cultured from throats and faeces. 30% (6/20) of asymptomatic animals tested had both types of K. pneumoniae in their faeces.

Natural Pathogens of Laboratory Mice, Rats, and Rabbits and Their Effects on Research

“…Klebsiella pneumoniae is a gramnegative bacterium normally inhabiting the intestinal tract of rats, mice, and numerous other animals. Reports of clinical disease in immunocompetent rodents are rare (208,275,325,579), and K. pneumoniae is therefore considered an opportunistic pathogen (475). The prevalence in rodent colonies is high and may increase with antibiotic treatment which eliminates other bacteria (272).…”

“…Transmission is primarily fecal-oral; aerosol transmission is effective (58). Clinical signs in mice most commonly include dyspnea, sneezing, cervical lymphadenopathy, inappetance, hunched posture, and rough coat (208,579), and those in rats include cervical and inguinal abscesses (275,325). Following hematogenous spread, focal abscess formation can occur in any organ.…”

Respiratory Diseases of Rodents and Rabbits

“…Systemic abscesses and granulomatous pneumonia have been reported in mice, and abscesses and draining fistulas have been reported in rats. 43…”

Rapid Identification of <i>Klebsiella pneumoniae</i>, <i>Corynebacterium kutscheri</i>, and <i>Streptococcus pneumoniae</i> Using Triplex Polymerase Chain Reaction in Rodents

“…K. pneumoniae is a gram-negative bacterium that normally inhabits the intestinal tract of rats, mice, and other animals [2]. As an opportunistic pathogen, K. pneumoniae has been reported to infect mice [14] and rats [5], and its prevalence is increased in antibiotic-treated nude rats to eliminate other bacteria [4]. C. kutscheri is a genus of grampositive bacteria.…”