Listeria spp

From Cow
Listeria monocytogenes, smear of brain stem, Gram's stain
Postmortem findings of generalised encephalitis associated with Listeria spp infection in a cow

Listeria spp are a genus of Gram-positive bacteria that cause listeriosis ('circling disease'), a cluster of symptoms associated with reproductive and neurological disease in cattle worldwide.

Listeriosis in a yearling cow

Species which are pathogenic in cattle include:

  • L. monocytogenes serotypes 1/2a, 1/2c[1][2]

This group of bacteria are ubiquitous saprophytes found in the environment and infections in winter grazing cattle causes sporadic outbreaks of septicaemia, encephalitis and abortion in cattle.

Clinical signs

Clinical signs are relatively sporadic in cattle, and single cases are commonly seen. Epidemic outbreaks have been recorded in some herds, although recovery rates are high.

Lethargy, Fever, septicaemia, facial paralysis and ataxia are the most common signs, and in pregnant cows, abortion may be noted in the last trimester[3].

Listeric encephalitis may recur on affected properties but outbreaks are usually of low incidence.

Diagnosis

Diagnosis of listeriosis is based on historical evidence of neurological disease, abortions and postmortem findings of encephalitis in aborted calves. Confirmation is achieved by isolation of L. monocytogenes from milk[4], submitted CSF and tissue samples[5]. Immunofluorescence, ELISA and PCR assay are accurate at establishing the presence of listeriosis in a herd.

A differential diagnosis would include ketosis, BSE, Histophilus spp, sporadic bovine encephalomyelitis, Chlamydophila spp, rabies, Echinococcus granulosus and lead poisoning.

Treatment

Listeriosis responds to broad-spectrum antimicrobials such as penicillins, ceftiofur, chloramphenicol, enrofloxacin, gentamicin, kanamycin, lincomycin, vancomycin and erythromycin[6].

Vaccines have equivocal results at preventing outbreaks. Monitoring of disease outbreaks can be achieved through regular milk sampling of dairy herds[7].

References

  1. Zhu L et al (2012) Prevalence and serotypes of Listeria monocytogenes contamination in Chinese beef processing plants. Foodborne Pathog Dis 9(6):556-560
  2. Fox EM et al (2012) PFGE analysis of Listeria monocytogenes isolates of clinical, animal, food and environmental origin from Ireland. J Med Microbiol 61(4):540-547
  3. Silva AP et al (2012) Transcription of pattern recognition receptors and abortive agents induced chemokines in the bovine pregnant uterus. Vet Immunol Immunopathol 145(1-2):248-256
  4. Amagliani G et al (2012) Microbiological surveillance of a bovine raw milk farm through multiplex real-time PCR. Foodborne Pathog Dis 9(5):406-411
  5. Di Palma S et al (2012) Comparative spatiotemporal analysis of the intrathecal immune response in natural listeric rhombencephalitis of cattle and small ruminants. Comp Immunol Microbiol Infect Dis 35(5):429-441
  6. Okada Y et al (2011) Antimicrobial susceptibilities of Listeria monocytogenes isolated in Japan. J Vet Med Sci 73(12):1681-1684
  7. Chiang YC et al (2012) Multiplex PCR and a chromogenic DNA macroarray for the detection of Listeria monocytogens, Staphylococcus aureus, Streptococcus agalactiae, Enterobacter sakazakii, Escherichia coli O157:H7, Vibrio parahaemolyticus, Salmonella spp. and Pseudomonas fluorescens in milk and meat samples. J Microbiol Methods 88(1):110-116