Pasteurella canis

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Pasteurella canis
Scientific classification Red Pencil Icon.png
Domain: Bacteria
Phylum: Pseudomonadota
Class: Gammaproteobacteria
Order: Pasteurellales
Family: Pasteurellaceae
Genus: Pasteurella
Species:
P. canis
Binomial name
Pasteurella canis
Mutters et al. 1985

Pasteurella canis is a Gram-negative, nonmotile, penicillin-sensitive coccobacillus of the family Pasteurellaceae. [1] Bacteria from this family cause zoonotic infections in humans, which manifest themselves as skin or soft-tissue infections after an animal bite. It has been known to cause serious disease in immunocompromised patients. [2] [3]

Contents

Pasteurella was first described around 1880 and thought to be associated with chicken cholera and hemorrhagic septicemia in animals. The genus was first cultured in 1885. In 1920, strains of Pasteurella were isolated and observed in human infections. [1]

Nomenclature

“Micrococcus gallicidus” was the first scientific name used for these bacteria. [4] [5] For a short time, the bacteria were unofficially placed in different genera, such as Octopsis, Coccobacillus , and Eucystia. In 1887, genus “Pasteurella” was proposed to honor Louis Pasteur for his critical discoveries in the field of microbiology. [1]

Before molecular technology was available, species were often labeled based on staining and the hosts from where species were isolated. [1] The name "multocida" was ultimately adopted to represent all the Pasteurella species. [1] [6] Until 1932, the genus Pasteurella only consisted of the species type Pasteurella multocida . [6] Pasteurella canis sp. nov. was previously classified as P. multocida biotype 6 or “dog-type” strains. In 1985, Pasteurella underwent taxonomic reclassification based on DNA hybridization, resulting in several subspecies of P. multocida and new Pasteurella species, including P. canis. [1]

P. canis includes two biotypes: biovar 1 originated from canines, whereas biovar 2 originated from bovines. The two biotypes are distinguishable from an indole test: biovar 1 is indole positive whereas biovar 2 is indole negative. [1]

Microbiology

P. canis is a Gram-negative coccobacillus that shows bipolar staining. [3] P. canis forms small, grey-colored, round, and smooth colonies. [2] [7] It is also nonhaemolytic and nonmotile. [8]

P. canis is reported as aerobic and facultative anaerobic in different sources. [2] [9] It metabolizes both glucose and sucrose. [8] In addition to morphological typing, biochemical tests are commonly used to identify the species. P. canis is positive for catalase, oxidase, and ornithine decarboxylase, but negative for lysine decarboxylase, V-factor (nicotinamide adenine dinucleotide), D-mannitol, dulcitol, D-sorbitol, urease, maltose, and L-arabinose. [1] [8] [10] It can also be indole positive or negative depending on the biotype. [10]

Molecular typing

Molecular analysis of the genome has become the popular method to identify bacteria. The genome of P. canis has yet to be fully sequenced, but several genes and their sequences were already identified. [11] Among them, 16S rRNA, 23S rRNA, RNA polymerase subunit B (rpoB), and manganese-dependent superoxide dismutase (sodA) are used to study Pasteurella phylogeny. [12] [13] [14] However, molecular and biochemical analyses often show conflicting results. For example, research has suggested some P. canis strains were in fact members of P. multocida based on DNA analysis. [10] [12] Phylogenetic analysis of P. canis and P. dagmatis also showed conflicting results, based on their 16s rRNA sequences and biochemical tests done on the strains. [15]

Disease

P. canis is an opportunistic pathogen that can infect both animals and humans.

Animal infections

P. canis can be found in healthy domesticated, farm-raised, and wild animals, such as dogs, cats, rabbits, horses, sheep, cattle, ferrets, deer, and even California sea lions. The bacteria are normally isolated from the oral cavities and respiratory tracts of these animals. [2] [16] [17] [18] [19] [20] P. canis biotype 1 was shown to secrete a toxin analogous to P. multocida toxin, but its identity is unknown. [21] P. canis is responsible for a number of canine infections, including systemic infection, external otitis, bacterial rhinitis, vertebral osteomyelitis, meningomyelitis (a type of myelitis), bronchopneumonia, tracheitis, paranasal sinus inflammation, and toxicosis. [8] [15] [22] [23] [24] Horses infected with the bacteria may develop arthritis. [17] The bacteria also cause pneumonia in cattle and various infections in sheep, cats, rabbits, and deer. [10] [15] [16]

Human infections

P. canis usually does not affect humans [25] but may be transmitted from animals to humans through animal bites, scratches, or licking over wounds. [7] [22] However, some patients developed infections without any scratches and puncture wounds. [26] In one case, a patient exposed to rabbit secretions was infected with P. canis. [20] Those with rheumatoid arthritis, cirrhosis, and diabetes mellitus are more susceptible to the bacteria. Patients who are immunocompromised also have higher risk of infections. [2]

P. canis often causes soft-tissue infections and wound infections, as well as systemic bacteremia in humans. [2] [3] [7] [20] These infections include peritonitis, conjunctivitis, osteomyelitis, and arthritis. [26] [27] [28] Joint prosthetics can also be infected by the bacteria. [29] Less commonly, this bacterium may result in respiratory infections, septic arthritis, endocarditis, and meningitis. Most patients with pulmonary infections caused by this species are elderly with pre-existing chronic lung diseases such as COPD. [25]

Antibiotics treatment and resistance

Many common antibiotics can successfully treat P. canis infections in both humans and animals. P. canis has shown sensitivity to ampicillin (penicillin), cefuroxime (second-generation cephalosporin), most third-generation cephalosporins (cefixime, cefotaxime, ceftriaxone, and cefoperazone), ciprofloxacin (quinolones), trimethoprim/sulfamethoxazole (sulfonamides), chloramphenicol, most aminoglycosides, and tetracycline. However, the bacterium is also resistant to numerous drugs, such as dicloxacillin (penicillin), some aminoglycosides (spectinomycin and neomycin), vancomycin (glycopeptides), cephalexin and cefadoxil (first-generation cephalosporin), erythromycin (macrolides), and imipenem (carbapenem). [2] [7] [28]

See also

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References

  1. 1 2 3 4 5 6 7 8 Mutters, R; P. Pohl, S.; Frederiksen, W.; Mannheim, W. (1985). "Reclassification of the Genus Pasteurella Trevisan 1887 on the Basis of Deoxyribonucleic Acid Homology, with Proposals for the New Species Pasteurella dagmatis, Pasteurella canis, Pasteurella stomatis, Pasteurella anatis, and Pasteurella langaa". International Journal of Systematic Bacteriology. 35 (3): 309–322. doi: 10.1099/00207713-35-3-309 .
  2. 1 2 3 4 5 6 7 Hara, H; Ochiai, T.; Morishima, T.; Arashima, Y.; Kumasaka, K.; Kawano, K. (2002). "Pasteurella canis osteomyelitis and cutaneous abscess after a domestic dog bite". Journal of the American Academy of Dermatology. 46 (5 Supplement): S151–S152. doi:10.1067/mjd.2002.106350. PMID   12004298.
  3. 1 2 3 Albert, T.J.; Stevens, D.L. (2010). "The first case of Pasteurella canis bacteremia: a cirrhotic patient with an open leg wound". Infection. 38 (6): 483–485. doi:10.1007/s15010-010-0040-1. PMID   20623245. S2CID   23668828.
  4. ↑ Illinois Industrial University, Board of Trustees (1882). Annual Report of the Board of Trustees of the Illinois Industrial University.
  5. ↑ Burrill, T.J. "New species of Micrococcus (bacteria)". Am. Nat. 17: 319–320.
  6. 1 2 Sneath, P.H.A. (1982). "Status of nomenclatural types in the Approved Lists of Bacterial Names". Int. J. Syst. Bacteriol. 32 (4): 459–460. doi: 10.1099/00207713-32-4-459 .
  7. 1 2 3 4 Rashid, N; Zam, Z.; MdNoor, S.; Siti-Raihan, I; Azhany, Y. (2012). "Pasteurella canis Isolation following Penetrating Eye Injury: A Case Report". Case Reports in Ophthalmological Medicine. 2012: 362–369. doi: 10.1155/2012/362369 . PMC   3350076 . PMID   22606491.
  8. 1 2 3 4 de la Puente Redondo, V.A.; Gutierrez Martin, C.B.; Garcia del Blanco, N.; Antolin Ayala, M.I.; Alonso Alonso, P.; Rodriguez Ferri, E.F. (2000). "Systemic Infection by Pasteurella canis Biotype 1 in Newborn Puppies". Journal of Comparative Pathology. 123 (2–3): 195–197. doi:10.1053/jcpa.2000.0394. PMID   11032675.
  9. ↑ Goldstein, E.J.C.; Citron, D.M.; Vreni Merrian, C. (1999). "Linezolid Activity Compared to Those of Selected Macrolides and Other Agents against Aerobic and Anaerobic Pathogens Isolated from Soft Tissue Bite Infections in Humans". Antimicrobial Agents and Chemotherapy. 43 (6): 1469–1474. doi:10.1128/aac.43.6.1469. PMC   89299 . PMID   10348773.
  10. 1 2 3 4 Christensen, H; Angen, Ø.; Olsen, J.E.; Bisgaard, M. (2004). "Revised description and classification of atypical isolates of Pasteurella multocida from bovine lungs based on genotypic characterization to include variants previously classified as biovar 2 of Pasteurella canis and Pasteurella avium". Microbiology. 150 (6): 1757–1767. doi:10.1099/mic.0.26720-0. PMID   15184562.
  11. ↑ "Pasteurella canis". NCBI Taxonomy Browser. Retrieved April 19, 2013.
  12. 1 2 Kainz, A; Lubitz, W.; Busse, H.J. (2000). "Genomic Fingerprints, ARDRA Profiles and Quinone Systems for Classification of Pasteurella sensu stricto". Systematic and Applied Microbiology. 23 (4): 494–503. doi:10.1016/s0723-2020(00)80023-5. PMID   11249019.
  13. ↑ Król, J; Florek, M.; Pliszczak-Król, A.; Staroniewicz, Z. (2006). "Microbiologic analysis of bite wounds in humans caused by dogs and cats". Medycyna Weterynaryjna. 62 (5): 498.
  14. ↑ Król, J; Bania, J.; Florek, M.; Podkowik, M.; Pliszczak-Król, A.; Staroniewicz, Z. (2011). "Genetic Diversity of Pasteurella dagmatis as Assessed by Analysis of the 16S rRNA and rpoB Gene Sequences". Curr. Microbiol. 63 (1): 87–93. doi:10.1007/s00284-011-9949-6. PMC   3104006 . PMID   21573831.
  15. 1 2 3 Sellyei, B; Wehmann, E.; Makrai, L.; Magyar, T. (2011). "Evaluation of the Biolog system for the identification of certain closely related Pasteurella species". Diagnostic Microbiology and Infectious Disease. 71 (1): 6–11. doi:10.1016/j.diagmicrobio.2011.04.016. PMID   21795002.
  16. 1 2 Biberstein, E.L.; Jang, S.S.; Kass, P.H.; Hirsh, D.C. (1991). "Distribution of indole-producing urease-negative Pasteurellas in animals". Journal of Veterinary Diagnostic Investigation. 3 (4): 319–323. doi: 10.1177/104063879100300408 . PMID   1760464.
  17. 1 2 Bourgault, A; Bada R.; Messier, S. (1994). "Isolation of Pasteurella canis from a foal with polyarthritis". Can Vet J. 35 (4): 244–245. PMC   1686756 . PMID   8076283.
  18. ↑ Hansen, M.J.; Bertelsen, M.F.; Christensen, H.; Bisgaard, M.; Bojesen, A.M. (2012). "Occurrence of Pasteurellaceae bacteria in the oral cavity of selected marine mammal species". Journal of Zoo and Wildlife Medicine. 43 (4): 828–835. doi:10.1638/2011-0264r1.1. PMID   23272350.
  19. ↑ Sarkozi, R; Makrai, L.; Fodor, L. (2011). "Characterization of Pasteurella species isolated from oral cavity of cats". Magyar Allatorvosok Lapja. 133 (9): 540–545.
  20. 1 2 3 Yefet, E; Abozaid, S.; Nasser, W.; Peretz, A.; Zarfin, Y. (2011). "Unusual infection--Pasteurella canis bacteremia in a child after exposure to rabbit secretions". Harefuah. 150 (1): 13–5, 70. PMID   21449149.
  21. ↑ Holst, E; Rollof, J.; Larsson, L.; Nielsen, J.P. (1992). "Characterization and Distribution of Pasteurella Species Recovered from Infected Humans". Journal of Clinical Microbiology. 30 (11): 2984–2987. doi: 10.1128/JCM.30.11.2984-2987.1992 . PMC   270564 . PMID   1452670.
  22. 1 2 Csebi, P; Jakab, C.; Janosi, K.; Sellyei, B.; Ipolyi, T.; Szabo, Z. (2010). "Vertebral Osteomyelitis and Meningomyelitis Caused by Pasteurella canis in a Dog – Clinicopathological Case Report". Acta Veterinaria Hungarica. 58 (4): 413–421. doi:10.1556/avet.58.2010.4.2. PMID   21087911.
  23. ↑ Knotek, Z; Fichtel, T.; Kohout, P.; Benák, J. (2001). "Diseases of Nasal Cavity in the Dog. Aetiology, Symptomatology, Diagnostics". Acta Vet. Brno. 70 (1): 73–82. doi: 10.2754/avb200170010073 .
  24. ↑ Zamankhan, M.H.; Jamshidi, S.; Zahraei, S.T. (2010). "Identification and antimicrobial susceptibility patterns of bacteria causing otitis externa in dogs". Vet Res Commun. 34 (5): 435–444. doi:10.1007/s11259-010-9417-y. PMID   20526674. S2CID   8911559.
  25. 1 2 Faceira, Ana; Póvoa, Sara; Souteiro, Pedro; Ceia, Filipa; Ferreira, Susana (March 2017). "Human infection by Pasteurella canis – A case report". Porto Biomedical Journal. 2 (2): 63–65. doi:10.1016/j.pbj.2017.01.005 . Retrieved 6 March 2023.
  26. 1 2 Hazelton, M.J.; Axt, M.W.; Jones, C.A. (2013). "Pasteurella canis Osteoarticular Infections in Childhood: Review of Bone and Joint Infections Due to Pasteurella Species Over 10 Years at a Tertiary Pediatric Hospital and in the Literature". Journal of Pediatric Orthopaedics. 33 (3): E34–E38. doi:10.1097/bpo.0b013e318287ffe6. PMID   23482278. S2CID   20655243.
  27. ↑ Balikoglu-Yilmaz, M; Yilmaz, T.; Esen, A.B.; Engin, K.N.; Taskapili, M. (2012). "Pasteurella canis and Granulicatella adiacens Conjunctivitis Outbreak Resistant to Empirical Treatment in a Child Welfare Agency". Journal of Pediatric Ophthalmology and Strabismus. 49 (5): 314–319. doi:10.3928/01913913-20120710-02. PMID   22800794.
  28. 1 2 Castellano, I; Marín, J.P.; Gallego, S.; Mora Rangel, G.; Suarez, M.A.; Deira, J.L.; Garcia–Bernalt, V.; Novillo, R.; Gómez–Martino, J.R. (2011). "Pasteurella canis Peritonitis in a Peritoneal Dialysis Patient". Peritoneal Dialysis International. 31 (4): 503–504. doi:10.3747/pdi.2011.00007. PMID   21799062. S2CID   19793398.
  29. ↑ Mondo, D; Bouillet, B.; Lesens, O.; Descamps, D. (2010). "First report of a total knee arthroplasty infected by Pasteurella canis". Médecine et Maladies Infectieuses. 40 (10): 600–1. doi:10.1016/j.medmal.2010.02.006. PMID   20462714.
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