Mycoplasma hyorhinis infections

Identity

Preferred Scientific Name

• Mycoplasma hyorhinis infections

International Common Names

• English: enzootic pneumonia of pigs; mycoplasma arthritis and septicemia in pigs; mycoplasma arthritis and septicemia in pigs; mycoplasmal arthritis; mycoplasmal polyserositis; otitis in pigs; otitis media, externa, interna, middle and inner ear infections; polyarthritis in pigs; polyserositis in pigs

Pathogen/s

Overview

M. hyorhinis, first characterized by Switzer (1955), is a common contaminant of the upper respiratory tract of pigs worldwide, occasionally causing polyarthritis and polyserositis in young animals. It is often found in association with the more fastidious and economically more important M. hyopneumoniae, the primary cause of enzootic pneumonia in pigs, and other bacteria such as Actinobacillus spp. where it may exacerbate disease; it may also overgrow M. hyopneumoniae in culture. It has been shown to be a primary cause of acute eustachitis and otitis in piglets. Recently, it has been thought to exacerbate porcine reproductive and respiratory syndrome (PRRS). M. hyorhinis is also a common contaminant of cell cultures which it probably infects via the trypsin; once established in cell cultures it is very difficult to eliminate.

Host Animals

Systems Affected

Distribution

M. hyorhinis is found wherever pigs are kept.

Distribution Table

The distribution in this summary table is based on all the information available. When several references are cited, they may give conflicting information on the status. Further details may be available for individual references in the Distribution Table Details section which can be selected by going to Generate Report.

Pathology

Gross lesions consist of serofibrinous inflammation of the membranes lining the pericardial, pleural and peritoneal cavities and serofibrinous to serosanguineous arthritis. In the chronic stages, there are often lesions in the body cavities and chronic arthritis (Ross, 1992). These features are not pathnomonic and other bacteria including Haemophilus parasuis, Streptococcus suis and Pasteurella multocida may also give similar lesions sometimes in collaboration with M. hyorhinis. It has been suggested that while M. hyorhinis can be regarded as a cause of polyserositis in piglets it requires the synergic presence of other bacteria in order for it to spread from the respiratory tract to the serous cavities (Friis and Feenstra, 1994).

M. hyorhinis has been isolated from the auditory tubes and tympanic cavities of piglets exhibiting otitis and eustachitis, leading to the possibility that the mycoplasma may be the primary cause of these ear infections (Morita et al., 1993; Kazama et al., 1994; Morita et al., 1999). Further evidence of its pathogenicity was shown with experimental infections; intranasal infection of specific pathogen free pigs led to inflammation of the auditory tubes and tympanic cavities (Morita et al., 1999).

Diagnosis

Lesions of serofibrinous to fibropurulent polyserositis and arthritis in 3-10 week old piglets are suggestive of M. hyorhinis but are not characteristic, as Haemophilus parasuis and Streptococcus suis can cause similar lesions; laboratory diagnosis is necessary for confirmation. Samples of choice for mycoplasma isolation include joint fluid and synovial membranes from pigs with polyarthritis; and samples of pleura, pericardium and peritoneum from cases of polyserositis. M. hyorhinis grows rapidly in most media, producing 'centred' colonies within 2-3 days. It can be identified by traditional typing tests such as growth inhibition and metabolic inhibition techniques using hyperimmune rabbit antiserum but antigenic variability amongst strains may make these methods unreliable; immunofluoescent antibody methods are preferred (Armstrong, 1994).

Serological tests including complemement fixation test and indirect haemagglutination assays have been described and antibodies can be detected in blood serum and synovial fluid 6 weeks after infection (Kobisch, 1983). However these methods are not widely available and culture is the preferred method.

• Roughned hair coat
  
• Moderate temperature elevations
  
• Listlessness
  
• Moderate inappetance
  
• Reluctance to move
  
• Abdominal tenderness
  
• Lameness
  
• Swollen joints
  
• 'Tucked up' appearance'
  
• Laboured breathing
  
• Stretching movements
  
• Lying in a sternal recumbency
  
• Head tilt (otitis media)

List of Symptoms/Signs

Disease Course

Outbreaks of polyserositis generally occur in piglets of 3-10 weeks of age but also occasionally in young adults (Ross, 1993). The incubation period is about one week following infection or after the onset of stress. Clinical disease caused by M. hyorhinis is characterized by laboured breathing, lameness, decreased appetite, elevated temperature (40-40.6°C) and abdominal tenderness; the hair coat may have a roughened appearance. Joint disease is usually transient but can persist for up to 6 months.

Evidence that M. hyorhinis is a primary cause of acute and chronic disease has been provided following intranasal and intrperitoneal infections of young piglets (Whittlestone, 1979; Kobisch, 1983). Clinical signs included hyperthermia, joint swelling, lameness and growth retardation; polyserositis and arthritis were clearly seen but pneumonia and rhinitis were absent. In the acute stages, serofibrinous pericarditis, pleuritis and peritonitis were seen accompanied by hypertrophy of the synovial membranes and an increase in synovial fluid. In the chronic disease, lesions were composed of fibrinoid adhesions and articular erosion. Microscopic changes included fibrinous inflammation of the serous membrane and infitration by mononuclear cells. M. hyorhinis was recovered widely from tissues. A difference in the virulence of field strains has been noted.

Other workers have been able to reproduce lung lesions identical to those caused by M. hyopneumoniae, the major cause of enzootic pneumonia (Gois and Kuksa, 1974; Armstrong et al., 1984)

The persistence of M. hyorhinis antigens in the joint tissues long after mycoplasma isolation ceases to be observed suggests that auto-immune mechanisms may be involved in joint damage; re-inoculation of killed organisms 18 months later can induce further cases of arthritis (Cole et al., 1985).

Epidemiology

M. hyorhinis normally inhabits the mucous membranes of the upper respiratory tract and tonsils (Friis and Feenstra, 1994) and is present in an estimated 10% of normal nasal cavities in adult and growing pigs (Ross, 1992). It has occasionally been isolated from the conjunctiva (Friis, 1976) and is frequently found in the joints of fattening pigs where it may play a role in arthritis. Adult carrier pigs transmit the mycoplasma to the litter where it spreads rapidly via aerosol and contact; many of the piglets may have clinically inapparent nasal and tracheobronchial infections. From the respiratory tract, the mycoplasma can spread haematogenously producing characteristic serofibrinous lesions in the pericardial, pleural and peritoneal cavities (Kobisch and Friis, 1996). It has been estimated to infect 2-5% of all pigs (Whittlestone, 1979).

Recently, M. hyorhinis has been implicated in fatal cases of PRRS because of its isolation from severe pulmonary lesions along with viruses thought to be responsible for the syndrome (Kawashima et al., 1996; Kobayashi et al., 1996; Shibata et al., 1996). A synergistic link may occur between M. hyorhinis and Pasteurella multocida; it has been shown that M. hyorhinis had no effect on the pneumonic lesion scores in naturally infected pigs unless P. multocida is present (Falk and Lium, 1990).

Impact: Economic

It is not possible to gauge the economic effects of M. hyorhinis infections, as generally these diseases are multifactorial.

Disease Treatment

In vitro studies have demonstrated the effectiveness of a range of antibiotics including (in order of potency) tetracycline, tiamulin, enrofloxacin, tylosin and lincomycin against M. hyorhinis in Denmark (Aarestrup et al., 1998). However, in Japan 10% of strains showed resistance to all 14- and 16-membered macrolide antibiotics tested; tiamulin was the most effective antibiotic (Kobayashi et al., 1996). As with many mycoplasma diseases, those caused by M. hyorhinis are usually refractory to antibiotic treatment, particularly in clinically sick pigs (Kobisch and Friis, 1996); early treatment is recommended.

No vaccines are currently available or considered desirable.

Prevention and Control

The widespread distribution of M. hyorhinis makes disease prevention difficult. As stress appears to play a major role in disease outbreaks, unnecessary movement of pigs, overcrowding and temperature fluctuations should be avoided; an optimal environment should be maintained, with particular attention made to air quality and ventilation.

References

Aarestrup FM; Friis NF; Szancer J, 1998. Antimicrobial susceptibility of Mycoplasma hyorhinis in a liquid medium compared to a disc assay. Acta Veterinaria Scandinavica, 39(1):145-147; 7 ref.

Armstrong CH, 1994. Porcine mycoplasmas. Mycoplasmosis in animals: laboratory diagnosis., 68-83; 25 ref.

Armstrong CH; Schiedt AB; Thacker HL; Runnels LJ; Freeman MJ, 1984. Evaluation of criteria for the postmortem diagnosis of mycoplasmal pneumonia of swine. Canadian Journal of Comparative Medicine, 48(3):278-281; 17 ref.

Barigazzi G; Guadagnini PF; Valenza F, 1990. The role of mycoplasms in the pathogenesis of respiratory diseases of pigs in Italy. Rivista di Suinicoltura, 31(3):71-80; 43 ref.

Bulnes C; Joa R; Martinez A, 1999. Patologia pulmonar asociada a infeccion por Mycoplasma sp. en cerdos de matadero. [Lung pathology associated with Mycoplasma sp. infection in pigs.] Revista de Salud Animal, 21(3):153-159.

Cole BC; Washburn LR; Taylor-Robinson D, 1985. Mycoplasma-induced arthritis. The mycoplasmas. Volume IV. Mycoplasma pathogenicity, 107-160; 9pp. of ref.

Copes J; Nievas F; Cerda R; Perfumo C, 1995. Isolation and properties of mycoplasmas from the lungs of slaughtered pigs. analecta Veterinaria, 1:27-30; 11 ref.

Falk K; Lium BM, 1990. Enzootic pneumonia of pigs - studies on field material on the relationship between the extent of lung lesions and the demonstration of Pasteurella multocida amd Mycoplasma hyorhinis.. Proceedings, International Pig Veterinary Society, 11th Congress, July 1-5, 1990, Lausanne, Switzerland., 93; 5 ref.

Friis NF, 1976. A serologic variant of Mycoplasma hyorhinis recovered from the conjunctiva of swine. Acta Veterinaria Scandinavica, 17(3):343-353.

Friis NF; Feenstra AA, 1994. Mycoplasma hyorhinis in the etiology of serositis among piglets. Acta Veterinaria Scandinavica, 35(1):93-98; 10 ref.

Gois M; Kuksa F, 1974. Intranasal infection of gnotobiotic piglets with Mycoplasma hyorhinis: differences in virulence of the strains and influence of age on the development of infection. Zentralblatt fur Veterinaermedizin, Reike B, 21:352-361.

Herrmann R, 1992. Genome structure and organization. In: Maniloff J ed. Mycoplasmas: molecular biology and pathogenesis. Washington DC, USA: American Society of Microbiology, 157-168.

Kawashima K; Yamada S; Kobayashi H; Narita M, 1996. Detection of porcine reproductive and respiratory syndrome virus and Mycoplasma hyorhinis antigens in pulmonary lesions of pigs suffering from respiratory distress. Journal of Comparative Pathology, 114(3):315-323; 21 ref.

Kazama S; Yagihashi T; Morita T; Awakura T; Shimada A; Umemura T, 1994. Isolation of Mycoplasma hyorhinis and Mycoplasma arginini from the ears of pigs with otitis media. Research in Veterinary Science, 56(1):108-110; 15 ref.

Kobayashi H; Morozumi T; Miyamoto C; Shimizu M; Yamada S; Ohashi S; Kubo M; Kimura K; Mitani K; Ito N; Yamamoto K, 1996. Mycoplasma hyorhinis infection levels in lungs of piglets with porcine reproductive and respiratory syndrome (PRRS). Journal of Veterinary Medical Science, 58(2):109-113; 16 ref.

Kobisch M, 1983. Pathogenicity of Mycoplasma hyorhinis. Yale Journal of Biological Medicine, 56(5):922-923.

Kobisch M; Friis NF, 1996. Swine mycoplasmoses. Revue Scientifique et Technique - Office International des épizooties, 15(4):1569-1605; 145 ref.

Morita T; Muraki Y; Awakura T; Shimada A; Umemura T, 1993. Detection of Mycoplasma hyorhinis in porcine eustachitis. Journal of Veterinary Medical Science, 55(3):475-477; 15 ref.

Morita T; Ohiwa S; Shimada A; Kazama S; Yagihashi T; Umemura T, 1999. Intranasally inoculated Mycoplasma hyorhinis causes eustachitis in pigs. Veterinary Pathology, 36(2):174-178; 14 ref.

Nevjestic A; Pasic S; Filipovic K; Hadzimuratovic M, 1991. Enzootic pneumonia in fattening pigs in Bosnia and Hercegovina. Praxis Veterinaria (Zagreb), 39(1):95-108; 59 ref.

Palmér E, 1995. Medicated feed for respiratory diseases of pigs. Svensk Veterinärtidning, 47(7):337; [comment on article in Svensk Veterinærtidning 1994, 46 (16)]; 3 ref.

Pettersson B; Uhlén M; Johansson KE, 1996. Phylogeny of some mycoplasmas from ruminants based on 16S rRNA sequences and definition of a new cluster within the hominis Group. International Journal of Systematic Bacteriology, 46(4):1093-1098; 24 ref.

Pfützner H, 1993. Mycoplasma infections of pigs. Praktische Tierarzt, 74(8):708-710, 713; 26 ref.

Popovic M; Pasic S; Jurisic Z, 1988. Study of porcine mycoplasmas in Bosnia and Herzegovina. I. Properties of the isolates. Veterinaria (Sarajevo), 37(2-3):245-248; 8 ref.

Ross RF, 1992. Mycoplasmal diseases. In: Leman AD, Straw B, Mengeling W, D'Allaire S, Taylor D, eds. Diseases of Swine. Ames, Iowa, USA: Iowa State University Press, 537-551.

Ross RF, 1993. Mycoplasmas - Animal pathogens. In: Kahane I, Adoni A, eds. Rapid Diagnosis of Mycoplasmas. New York, USA: Plenum Press, 69-110.

Sheldrake RF; Romalis LF, 1992. Evaluation of an enzyme-linked immunosorbent assay for the detection of Mycoplasma hyopneumoniae antibody in porcine serum. Australian Veterinary Journal, 69(10):255-258; 22 ref.

Shibata I; Okada M; Hayashi Y; Namimatsu T; Sakano T, 1996. Microbiological examination of the lungs and tonsils from fatal cases of porcine reproductive and respiratory syndrome. Journal of the Japan Veterinary Medical Association, 49(5):316-318; 17 ref.

Sobko AI; Nastenko VD; Berdnik VP; Schimmel D; Pfützner H, 1989. Development of procedures for immunizing piglets against mycoplasmosis. Archiv für Experimentelle Veterinärmedizin, 43(5):645-655; 25 ref.

Stipkovits L, 1990. What about M. [Mycoplasma] pneumonia. Pigs, 6(3):27, 29.

Switzer WP, 1955. Studies on infectious atrophic rhinitis. IV Characterisation of a pleuropneumonialike organism isolated from the nasal cavities of swine. American Journal of Veterinary Research, 16:540-544.

Weng CN, 1989. The morphology of porcine mycoplasmas growth in different media. Journal of the Chinese Society of Veterinary Science, 15(1):41-46; 14 ref.

Whittlestone P, 1979. Porcine mycoplasmas. In: Tully JG, Whitcomb RF, eds. The Mycoplasmas. Vol 2. New York, USA: Academic Press, 133-176.

Distribution References

Aarestrup F M, Friis N F, Szancer J, 1998. Antimicrobial susceptibility of Mycoplasma hyorhinis in a liquid medium compared to a disc assay. Acta Veterinaria Scandinavica. 39 (1), 145-147.

Armstrong C H, Schiedt A B, Thacker H L, Runnels L J, Freeman M J, 1984. Evaluation of criteria for the postmortem diagnosis of mycoplasmal pneumonia of swine. Canadian Journal of Comparative Medicine. 48 (3), 278-281.

Barigazzi G, Guadagnini P F, Valenza F, 1990. The role of mycoplasms in the pathogenesis of respiratory diseases of pigs in Italy. (Ruola dei micoplasmi nella patogenesi delle malattie respiratoire del suino in Italia.). Rivista di Suinicoltura. 31 (3), 71-80.

Bulnes C, Joa R, Martínez A, 1999. Lung pathology associated with Mycoplasma sp. infection in pigs. (Patología pulmonar asociada a infección por Mycoplasma sp. en cerdos de matadero.). Revista de Salud Animal. 21 (3), 153-159.

CABI, Undated. CABI Compendium: Status inferred from regional distribution. Wallingford, UK: CABI

CABI, Undated a. CABI Compendium: Status as determined by CABI editor. Wallingford, UK: CABI

Copes J, Nievas F, Cerda R, Perfumo C, 1995. Isolation and properties of mycoplasmas from the lungs of slaughtered pigs. (Aislamiento y caracterización de Mycoplasma sp. de pulmones de cerdos provientes de mataderos.). analecta Veterinaria. 27-30.

Friis N F, 1976. A serologic variant of Mycoplasma hyorhinis recovered from the conjunctiva of swine. Acta Veterinaria Scandinavica. 17 (3), 343-353.

Kobisch M, 1983. Pathogenicity of Mycoplasma hyorhinis. In: Yale Journal of Biological Medicine, 56 (5) 922-923.

Morita T, Muraki Y, Awakura T, Shimada A, Umemura T, 1993. Detection of Mycoplasma hyorhinis in porcine eustachitis. Journal of Veterinary Medical Science. 55 (3), 475-477.

Nevjestić A, Pašić Š, Filipović K, Hadžimuratović M, 1991. Enzootic pneumonia in fattening pigs in Bosnia and Hercegovina. (Enzootska pneumonija tovnih svinja u Bosni i Hercegovini.). Praxis Veterinaria (Zagreb). 39 (1), 95-108.

Palmér E, 1995. Medicated feed for respiratory diseases of pigs. (Fodermedicinering vid luftvägslidanden hos svin.). Svensk Veterinärtidning. 47 (7), 337.

Pfützner H, 1993. Mycoplasma infections of pigs. (Mykoplasmen-Infektion des Schweines.). Praktische Tierarzt. 74 (8), 708-710, 713.

Popović M, Pašić Š, Jurišić Z, 1988. Study of porcine mycoplasmas in Bosnia and Herzegovina. I. Properties of the isolates. (Proučavanje porcinih mikoplazmi u Bosni i Hercegovini. 1. Osobine izolata.). Veterinaria (Sarajevo). 37 (2-3), 245-248.

Sheldrake R F, Romalis L F, 1992. Evaluation of an enzyme-linked immunosorbent assay for the detection of Mycoplasma hyopneumoniae antibody in porcine serum. Australian Veterinary Journal. 69 (10), 255-258. DOI:10.1111/j.1751-0813.1992.tb09875.x

Sobko A I, Nastenko V D, Berdnik V P, Schimmel D, Pfützner H, 1989. Development of procedures for immunizing piglets against mycoplasmosis. Archiv für Experimentelle Veterinärmedizin. 43 (5), 645-655.

Stipkovits L, 1990. What about M. [Mycoplasma] pneumonia. Pigs. 6 (3), 27, 29.

SWITZER W P, 1955. Studies on infectious atrophic rhinitis. IV. Characterization of a pleuropneumonia-like organism isolated from the nasal cavities of swine. American Journal of Veterinary Research. 540-544.

Weng C N, 1989. The morphology of porcine mycoplasmas growth in different media. Journal of the Chinese Society of Veterinary Science. 15 (1), 41-46.

Whittlestone P, 1979. Porcine mycoplasmas. In: The Mycoplasmas, 2 [ed. by Tully JG, Whitcomb RF]. New York, USA: Academic Press. 133-176.

Distribution Maps