Contagious caprine pleuropneumonia and Mannheimia haemolytica
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Rev. sci. tech. Off. int. Epiz., 2006, 25 (3), 1153-1163 Contagious caprine pleuropneumonia and Mannheimia haemolytica-associated acute respiratory disease of goats and sheep in Afar Region, Ethiopia G. Shiferaw (1, 3), S. Tariku (2), G. Ayelet (2) & Z. Abebe (1) (1) Department of Microbiology, Kombolcha Regional Veterinary Laboratory, P.O. Box 9, Kombolcha, Ethiopia (2) National Veterinary Institute, P.O. Box 19, Debre Zeit, Ethiopia (3) Department of Microbiology, Immunology and Parasitology, Faculty of Medicine, Addis Ababa University, P. O. Box 9086, Addis Ababa, Ethiopia Submitted for publication: 28 February 2005 Accepted for publication: 6 October 2006 Summary In April 2002, an investigation into an outbreak of acute respiratory disease in goats and sheep in Milae (Afar), Ethiopia was conducted. The investigation involved 4 ﬂocks (722 sheep and 750 goats in total) and comprised the disease history, clinical and post-mortem examination, and microbiological analysis of nasal swabs, lung lesions, and pleural ﬂuid samples. Clinically diseased animals exhibited severe respiratory distress, and necropsy of two of the goats demonstrated ﬁbrinous pneumonia, lung sequestra, and excessive accumulation of straw coloured ﬂuid in the thoracic cavity. Mannheimia haemolytica biotype T was isolated from nine (six goats and three sheep) out of 23 nasal swabs (39.1%). In the two necropsied animals Mycoplasma capricolum subsp. capripneumoniae (Mccp) was isolated from the lungs, and Mannheimia haemolytica biotype T was isolated from lung lesions and thoracic ﬂuid. An unidentiﬁed Mycoplasma species was isolated from the thoracic ﬂuid of one of the goats. Pseudomonas aeruginosa was isolated from a lung sequestrum of one of the necropsied goats. In vitro antimicrobial susceptibility test results indicated that two (33.3%) of the six M. haemolytica isolates that were tested were resistant to ampicillin and penicillin G, three (50%) to tetracycline, four (66.7%) to oxacillin, five (83.3%) to erythromycin, and six (100%) to clindamycin. Pseudomonas aeruginosa was resistant to all of the different classes of antimicrobials that were tested. Pleuropneumonia caused by Mccp, and secondary complications caused by M. haemolytica and the other unidentiﬁed Mycoplasma species, were conﬁrmed as the cause of the outbreak. Morbidity was not associated with the species of animals affected (P > 0.05); however, mortality was signiﬁcantly higher in goats than sheep (P < 0.05). Keywords Acute respiratory disease – Contagious caprine pleuropneumonia – Ethiopia – Goat – Mannheimia haemolytica biotype T – Mycoplasma capricolum subsp. capripneumoniae – Pseudomonas aeruginosa – Sheep. 1154 Rev. sci. tech. Off. int. Epiz., 25 (3) Introduction occurred in Milae District of Afar Region, Ethiopia. The outbreak generated media attention (23), and in response to the request from regional authorities, the outbreak was Small ruminants in Africa represent 21% of the world’s investigated. This study describes the ﬁndings of the small ruminant population. The population of sheep in investigation. Africa represents 17% of the total world sheep population, while goats represent 30% of the world goat population (9). Ethiopia possesses an estimated 11,438,200 and 9,620,800 heads of sheep and goats, respectively (6), equivalent to 2,105,900 tropical livestock units (TLU) Materials and methods (1 TLU = 250 kg; 1 sheep/goat = 0.1 TLU). Small General approach to the investigation ruminants in Africa are reared in different livestock production systems ranging from crop/livestock mixed A ﬁeld investigation was initiated on 2 April 2002 in Milae systems in the highlands, to pastoral systems in the arid District. As part of the investigation, the geographical area lowlands. Sheep and goats play a signiﬁcant role in the and the history of the disease were assessed, clinical and nation’s economy. Meat and milk are major sources of post-mortem examinations were carried out, and samples protein, and hides, live animals, and carcasses account for from both live and dead animals were taken for laboratory a signiﬁcant proportion of exports. In Ethiopia, sheep and analysis. Four ﬂocks were clinically examined, and two goats are affected by many infectious and parasitic diseases. goats from one of these ﬂocks, both of whom had severe Infectious diseases of small ruminants such as peste des respiratory distress, were provided by the owner for post- petits ruminants (PPR) (10), sheep and goat pox, mortem examination. The owners of all four ﬂocks were contagious caprine pleuropneumonia (CCPP) (7, 10, 19, interviewed (individually and in a group) using a checklist 21, 27), brucellosis, pneumonic pasteurellosis/ based on the format used by the World Organisation for mannheimiosis and maedi-visna (2) have been reported. Animal Health (OIE) in their monthly outbreak reports Considerable losses occur frequently as a result of (the list includes elements such as species of animal outbreaks of such infectious diseases; however, both the affected, number of cases and deaths, source of the disease, outbreaks and losses from such outbreaks are not well vaccination history, previous treatment, etc). documented. Diseases caused by parasites such as Fasciola, lungworms, Haemonchus and mange mites also hinder the full production potential of these resources. Study area The study area was situated within Milae District of Afar The classical Mycoplasma mycoides cluster contains Region. The district is located 135 km east of Kombolcha M. capricolum subsp. capripneumoniae (Mccp), and about 500 km north-east of Addis Ababa along the M. capricolum subsp. capricolum, M. mycoides subsp. capri, road to Djibouti. The outbreak area was geographically M. mycoides subsp. mycoides type LC (MmmLC), positioned at 11°24’476”N and 040°45’439”E at an M. mycoides subsp. mycoides type SC, and Mycoplasma sp. altitude of 703 metres above sea level (Fig. 1). The region bovine serogroup 7 (19). Many Mycoplasma species are is within an arid agro-ecological zone and is prone to capable of infecting goat and sheep lungs and inducing recurrent drought due to erratic rainfall. Multi-species pleuropneumonia. Contagious caprine pleuropneumonia pastoralism is the preferred and most practiced system of is a severe contagious disease of goats caused by Mccp. livestock production. Local breeds of goats and sheep are Unlike true CCPP, which is conﬁned to the thoracic cavity, relatively resistant to the harsh conditions of the area. They the disease caused by MmmLC, M. mycoides subsp. capri, serve as a source of milk and meat for the local households and M. capricolum subsp. capricolum is characterised by and live animals are sold to generate cash whenever the prominent lesions in other organs and/or parts of the body need arises. The district has an estimated 140,976 goats in addition to the thoracic cavity (26). Mycoplasma and 70,488 sheep (Afar Bureau of Agriculture, personal capricolum subsp. capripneumoniae was ﬁrst isolated and communication). Small ruminants are herded and housed shown to cause CCPP in Kenya. It has subsequently been separately from other species of animals. isolated in Sudan, Tunisia, Oman, Turkey, Chad, Uganda, Ethiopia, Niger, Tanzania, Eritrea, and the United Arab Emirates (26). In Ethiopia, CCPP occurs in most of the extensive goat rearing areas, namely, Afar, Borana, Omo Samples collected Valley, West Gojjam, and in the lowlands of Tigray (21, Samples collected from live animals (nasal swabs, serum, 27). The ﬁrst case was reported from Assosa District, and whole blood) and from the two necropsied goats (lung Western Ethiopia (21). lesions, pleural ﬂuid, and tracheal swabs) were placed in sterile bottles. Eye swabs were also collected from animals In the months of February and March 2002, an outbreak showing signs of keratoconjunctivitis. Tubes containing of a contagious acute respiratory disease of sheep and goats tryptone soya broth were immediately inoculated with Rev. sci. tech. Off. int. Epiz., 25 (3) 1155 Study Area Towns Lakes Regional Boundary Elevation Metres above sea level High: 4517 Low: -236 Fig. 1 Map of Ethiopia indicating the outbreak area nasal swab specimens for the isolation of Mannheimia. All characteristics and the results of the biochemical tests, of the samples were frozen (–20°C) and transported on ice isolates were classiﬁed and grouped according to genus to the regional government laboratory in Kombolcha and species. (within a day). In addition, samples of lung lesions and pleural ﬂuid were transported to a laboratory in Debre Zeit In vitro antimicrobial susceptibility (within two days) and stored at –20°C until processed. The agar disc diffusion technique using Mueller-Hinton medium as described by Jorgenson et al. (12) was applied to Mannheimia isolates from two lung samples and four Laboratory diagnosis nasal swabs, and to Pseudomonas isolated from one lung sample. Escherichia coli 25922 (ATCC) obtained from the Bacteriological analysis National Health and Nutrition Research Institute was used Nasal swabs (from 14 live goats and 9 live sheep) and as a quality control. Tests were considered to be valid when autopsy samples collected from the necropsied goats were results for the reference strain were within the expected subjected to conventional bacteriological examination in range speciﬁed by the Clinical and Laboratory Standards the regional laboratory (Kombolcha). Prior to culture, the Institute (CLSI [formerly NCCLS]). Pure colonies of samples were enriched via inoculation into tryptone soya bacteria were grown in tryptone soya broth. Bacterial broth (Oxoid, United Kingdom [UK]) and incubation at suspensions were prepared by matching the samples to 37°C. The enriched samples were then used to inoculate 0.5 McFarland turbidity standards and were then used to plates of blood and MacConkey agar (Oxoid, UK). inoculate Mueller-Hinton media. Antimicrobial discs Bacterial growths were subcultured to obtain pure (ampicillin, penicillin G, oxacillin, erythromycin, colonies, which appeared as Gram-negative short rods after tetracycline, clindamycin, and sulphafurazole; Oxoid, UK) Gram staining. On blood agar, the colony characteristics of were distributed on the inoculated plates using an pure cultures were examined and recorded. On antimicrobial dispenser and the plates were incubated at MacConkey agar, colony growth and lactose fermentation 37°C. Results were read after an incubation period of 18 to properties were observed and recorded. The following 24 hours. Interpretation was made using interpretative biochemical tests were subsequently performed: oxidase, standards described by Jorgenson et al. (12), which are catalase, indole, hydrogen sulphide, urease, glucose, based on CLSI performance standards for antimicrobial sucrose, salicine, and trehalose. Based on growth susceptibility testing (18). The zone diameter cut-off value 1156 Rev. sci. tech. Off. int. Epiz., 25 (3) provided for Gram-negative bacteria was used to evaluate affected in each of the ﬂocks. The disease covered a large susceptibility to ampicillin and penicillin, a cut-off value of geographical area, indicating a high transmission rate. The 14 mm was used to determine susceptibility to oxacillin, ﬂocks were not vaccinated for CCPP and clinically ill and the cut-off value provided for sulphonamides was used animals and suspected cases had been treated with to assess susceptibility to sulphafurazole (12). oxytetracycline, which seemed to reduce morbidity and mortality (although the survey team was unable to observe Mycoplasma isolation the animals for an extended period of time). Lung and thoracic ﬂuid specimens collected from the two More than 30,000 animals were at risk. Out of a total of necropsied goats were submitted to the National Veterinary 722 sheep and 750 goats from four ﬂocks, the morbidity Institute (Debre Zeit, Ethiopia) for Mycoplasma isolation rate was 57% and 53% and the mortality rate was 22% and and characterisation. Mycoplasma was isolated using 32% in sheep and goats, respectively. At the time that the Thiaucourt’s medium, which contained Bacto-PPLO broth present investigation was undertaken, the case fatality rate without crystal violet (Difco Laboratories), inactivated had reached 38% in the sheep population and 59% in the horse serum, yeast extract, glucose, sodium pyruvate, goat population. ampicillin, and thallium acetate. Tissues were homogenised in broth media using a sterile mortar and pestle. The homogenate was then streaked onto agar plates and the seeded agar plates were incubated at 37°C in a CO2 Clinical signs incubator for 14 days. The plates were checked daily for Both species developed the disease, though clinical signs the appearance of colonies. Pure colonies were selected were more severe in goats. Fever, loss of appetite and and biochemical tests for the breakdown of glucose, condition, hyperpnoea, expiratory grunt, mucoid nasal hydrolysis of arginine, reduction of tetrazolium chloride, discharge, and open-mouth breathing were observed in phosphatase activity, and arginine hydrolysis were carried clinically sick animals (Fig. 2). In one ﬂock, a few of the out on each isolate. Isolated Mycoplasma colonies were also animals had keratoconjunctivitis with corneal opacity and examined by growth inhibition and dot-blot tests four of the animals had diarrhoea. using Mccp monoclonal antibodies (Centre de coopération internationale en recherche agronomique pour le développement - Elevage et médecine vétérinaire tropicale [CIRAD-EMVT]) (26). Virus isolation and serology for antibodies to peste des petits ruminants virus A portion of the specimens were also submitted for virus isolation to the Virology Laboratory at the National Veterinary Institute. Eighty-seven samples of sera were sent to the National Animal Health Research Center in Sebeta, Ethiopia, where they were tested for PPR using a competitive enzyme-linked immunosorbent assay (cELISA). Statistical analysis Data were presented using descriptive statistics and the Chi square test was used to test the null hypothesis of equality of clinical cases and deaths, resulting from the disease, between goats and sheep. Results Disease history The outbreak was ﬁrst reported in February. Herdsmen Fig. 2 claimed the disease was associated with a shortage of feed Nasal discharge and mouth breathing due to respiratory due to the long dry season. Both goats and sheep were distress Rev. sci. tech. Off. int. Epiz., 25 (3) 1157 Post-mortem ﬁndings Bacteriological analysis Necropsy examinations were performed on two goats Bacterial isolates were identiﬁed from the various samples provided by the owner of one of the ﬂocks. Inspection was based on growth characteristics, Gram staining, and concentrated on the thoracic cavity. Lesions were mainly primary and secondary biochemical test results. localised in one lung in both of the animals; the gross pathological observations were as follows: excess straw Nasal swab coloured fluid in the thoracic cavity, a red area of consolidation, slightly distended intralobular septa, pleural Using a variety of different biochemical tests the following adhesion, and two encapsulated foci containing whitish results were obtained: 9 of the 23 nasal swabs material (sequestra) (Figs 3a to 3d). (39.1%) were positive for Mannheimia haemolytica biotype Fig. 3a Fig. 3c Pneumonic lung with ﬁbrin deposition Lung with sequestra Fig. 3d Fig. 3b Deposits of ﬁbrin in the visceral pleura and excessive straw Lung lesion localised in one lung coloured ﬂuid in the thoracic cavity 1158 Rev. sci. tech. Off. int. Epiz., 25 (3) T (six from goats and three from sheep), 5 failed to be Mycoplasma investigation positive for M. haemolytica due to the results of one of the biochemical tests, and 9 (39.1%) were positive for Bacillus Mycoplasma was isolated from lung lesions and thoracic soecies. ﬂuid collected from the two necropsied goats. After cloning and subculture, three isolates (two from the lung and one from the pleural ﬂuid) were further identiﬁed to the Lung species level using biochemical tests and growth inhibition Mannheimia haemolytica biotype T was isolated from lung and dot-blot tests speciﬁc for Mccp. The isolates were lesions from both of the necropsied goats. Pseudomonas positive for glucose fermentation and reduction of aeruginosa was isolated from lung sequestra and exhibited tetrazolium chloride, negative for phosphatase activity, and the following characteristics: growth on MacConkey agar, negative for the hydrolysis of arginine. Two of the isolates lactose fermentation negative, oxidase positive, indol (from the lungs of both of the goats) were inhibited with doubtful, and glucose, sucrose, and salicine positive. Mccp hyperimmune serum and were positive for the dot- Pseudomonas aeruginosa colonies produced a blue pigment blot test, while the isolate from the pleural ﬂuid of one of on Mueller-Hinton agar and appeared red in colour in the goats was not inhibited by Mccp hyperimmune serum brilliant green agar. and was negative for the dot-blot test. Hence, from one of the goats, only Mccp was isolated, while from the other Pleural ﬂuid goat, Mccp was isolated from the lung and another Mycoplasma, which could not be identiﬁed, was isolated Mannheimia haemolytica biotype T was isolated from from the pleural ﬂuid. pleural ﬂuid collected from the two necropsied goats. Tracheal swab Virus isolation and peste des petits ruminants Bacillus species were isolated from tracheal swabs collected serology from the necropsied goats. No viruses were isolated and one animal was sero-reactive for PPR using the cELISA test. Eye swab Staphylococcus and Bacillus species were isolated from eye swabs taken from animals showing signs of keratoconjunctivitis. Discussion Based on clinical, necropsy, laboratory, and epidemiological ﬁndings, clinical disease was diagnosed as In vitro antimicrobial susceptibility CCPP, which is caused primarily by Mccp with secondary Mannheimia isolated from two lung and four nasal swab . invasion by M. haemolytica biotype T and P aeruginosa. samples, and Pseudomonas isolated from one lung sample, Mycoplasma capricolum subsp. capripneumoniae was were used for in vitro antimicrobial susceptibility tests. The isolated from lung lesions of both of the necropsied goats; results are presented in Table I. however, the species of Mycoplasma isolated from the Table I Results of antimicrobial susceptibility tests Mannheimia haemolytica Pseudomonas aeruginosa Antimicrobials Susceptible no. Intermediate no. Resistant no. Susceptible no. Intermediate no. Resistant no. of isolates (%) of isolates (%) of isolates (%) of isolates (%) of isolates (%) of isolates (%) Ampicillin (10 µg) 4 (66.7) 2 (33.3) 1 (100) Penicillin G (10 IU) 3 (50) 1 (16.7) 2 (33.3) 1(100) Oxacillin (1 µg) 2 (33.3) 1 (16.7) 4 (66.7) 1 (100) Erythromycin (15 µg) 2 (33.3) 1 (16.7) 5 (83.3) 1 (100) Tetracycline (30 µg) 4 (66.7) 3 (50.0) 1 (100) Sulphafurazole (100 µg) 2 (33.3) 1 (100) Clindamycin (2 µg) 6 (100.0) 1 (100) Rev. sci. tech. Off. int. Epiz., 25 (3) 1159 pleural ﬂuid of one of the goats could not be identiﬁed. Pneumonia in sheep and goats, primarily caused by Small ruminant respiratory disease often has a multi- Mycoplasma, is commonly complicated by factorial origin (4), which may have been the case in this Pasteurella/Mannheimia (4), which was observed in this outbreak. Mycoplasma capricolum subsp. capripneumoniae outbreak. The Mannheimia species/biotype isolated in caused the primary infection, at least in the goat upper respiratory tract (nasal swab) and lower respiratory population. Clinical disease may have occurred as a result tract (lung and pleural ﬂuid) samples was M. haemolytica of a new infection or may have been the result of a ﬂare-up biotype T. Isolates from both anatomic sites showed a of subclinical infection stimulated by environmental stress. similar antimicrobial susceptibility pattern. In a study During the outbreak period, the weather conditions were undertaken in calves with clinical signs of respiratory harsh (extreme ambient temperature) and there was a . disease, M. haemolytica and P multocida isolates obtained severe feed shortage. Primary infection of the lower from nasal and transtracheal swabs showed similar respiratory tract with Mycoplasma and Bordetella ribotyping and antibiotic susceptibility patterns (5). The parapertussis can increase the susceptibility of sheep and investigation suggested that a nasal swab culture can be goats to secondary M. haemolytica infection (4). Stress, predictive of bacterial pathogens within the lung and could induced by factors such as heat, overcrowding, exposure to be used to determine antibiotic susceptibility when the harsh weather conditions, poor ventilation, handling, and isolates are from acutely ill animals (5). A study transport, is a major predisposing factor (4). undertaken in the highlands of Ethiopia suggested that cases of pneumonic pasteurellosis were mainly caused by . M. haemolytica species (unpublished data, F Kebede and Gross pathological observations were consistent with CCPP; G. Shiferaw). however, the sequestra which were observed on necropsy are not a common characteristic of CCPP. Kusiluka et al. In vitro antimicrobial susceptibility test results could be demonstrated the concurrent presence of sequestra and used as preliminary information for further monitoring. M. capripneumoniae and M. mycoides subsp. mycoides in an Most interpretive criteria used to categorise veterinary outbreak of CCPP in Tanzania (14). Wesonga et al. reported pathogens as susceptible or resistant to antimicrobials in chronic pleuropneumonia with sequestra formations on vitro are based on data obtained from human pathogens necropsy at days 82 and 126 post-infection in goats and pharmacokinetics of drugs used in humans (20). The experimentally infected with Mccp (25). validity of these criteria when used in animal pathogens is questionable (24). From the six M. haemolytica isolates The present outbreak involved both sheep and goats; tested, all were resistant to clindamycin. Fifty percent of however, classical CCPP is described only in goats. A the isolates were resistant to tetracycline and 33.3% were possible explanation for the occurrence in sheep in this resistant to penicillin and ampicillin, which is indicative of outbreak is the presence of another pathogenic Mycoplasma a serious condition. Tetracycline (oxytetracycline) is a which was capable of causing disease in both species of common and widely used antimicrobial for treatment of animals (11, 22). Most of such Mycoplasma organisms pneumonic as well as other infectious diseases in small produce mastitis, arthritis, keratitis, pneumonia, and ruminants and other farm animals. Penicillin is the most septicaemia, which present as single conditions or in commonly available antimicrobial in Ethiopia and is the combination (1, 22, 26). In this particular outbreak the front-line drug for treatment of infectious disease in all pneumonic conditions were predominant, though animals species of livestock. in one of the ﬂocks also exhibited keratitis and diarrhoea. The presence of lesions in other parts of the body Pseudomonas aeruginosa was isolated from lung sequestra (a characteristic of disease caused by members of the from one of the necropsied goats and was found to be M. mycoides cluster other than Mccp) may have been resistant to the spectrum of antimicrobials tested. overlooked during necropsies and clinical examinations, Pseudomonas is an opportunistic organism and most which were concentrated on the thoracic cavity. The infections with this organism have been localised to the number of cases of the disease (morbidity) had no respiratory tract and occur in patients with underlying association with the species of animal (P > 0.05), while the pulmonary disease (13, 17). Pseudomonas is considered to severity of the disease (mortality) was signiﬁcantly higher be a true pathogen when it is isolated from a sterile site in goats than sheep (P < 0.05). Absence of post-mortem (13), and in this particular outbreak was not considered to examination, bacteriology analyses, and specific be an important pathogen because it was isolated from a investigation for Mycoplasma in the lungs of the sheep lung lesion of only one goat. Had the isolated Pseudomonas made it very difﬁcult to determine the primary cause of been classiﬁed as a signiﬁcant pathogen, treatment of the infection in sheep. However, it should be noted that Mccp infection could have been potentially frustrating since the and antibodies to Mccp have been reported in pneumonic bacterium is typically resistant to multiple classes of sheep in outbreaks of CCPP (3, 8), and, therefore, antimicrobial agents (13, 17), which was demonstrated by Mccp could be the primary cause of disease seen in sheep the in vitro susceptibility results in this study. In addition, in this outbreak. susceptible organisms can become resistant during therapy 1160 Rev. sci. tech. Off. int. Epiz., 25 (3) due to the production of antibiotic inactivating enzymes and authority at various levels, has to be implemented to (e.g. -lactamases), or through mutations in the genes control endemic diseases in these areas. coding the outer membrane pore proteins, or by the transfer of plasmid-mediated resistance from a resistance This study demonstrated the presence of Mccp and organism to a susceptible one (17). M. haemolytica in a single outbreak in which both goats and sheep were clinically affected, indicating the necessity This study indicated the emergence of strains of animal for strong surveillance based on laboratory isolation and pathogens resistant to commonly used antimicrobials. identiﬁcation of infectious organisms. There is a need for Further investigation on the clinical efficacy of the development and standardisation of rapid, inexpensive antimicrobials and the impact of emerging resistant strains diagnostic tests for primary screening in the ﬁeld prior to of animal pathogens on human health is required. conﬁrmatory laboratory diagnosis as part of surveillance and control programmes. Promising experimental results The interaction of a number of factors can predispose have been reported using latex agglutination tests (capsular animals to acute respiratory disease. The reduction of polysaccharide antigen and antibody detection tests) stressful conditions (e.g. provision of supplementary feed (15, 16). during periods of drought) and the immunisation of ﬂocks against endemic diseases associated with the respiratory disease complex (CCPP, PPR, parainfluenza, and M. haemolytica) are important elements of any preventive Acknowledgements herd health programme. The primary method of We would like to thank Dr Tsegaw Fentie, former Head of containing the outbreak was the mass treatment of infected the Kombolcha Regional Veterinary Laboratory, for ﬂocks using antimicrobials (oxytetracycline), which helped arranging the field visit to undertake the present to reduce morbidity and mortality. Although alternative investigation. We are indebted to Dr Lakemariham Yigezu options to reduce the mortality of the flocks were of the National Animal Health Research Institute (Sebeta, unavailable, caution should be exercised in the mass Ethiopia) for analysis of the sera for PPR. Drs. Amsalu application of antimicrobials as there is a risk of creating a Demessie and Girma Abeto are also appreciated for their pool of carriers and/or selecting resistant pathogens. encouragement. Last but not least, we would also like to Pastoralists need to be encouraged and supported to apply thank Mr Atsemachew Bizawerk from the International self-imposed quarantine measures. An early detection, Livestock Research Institute for providing the map early warning, and early reaction system, which requires of Ethiopia. the involvement of stock owners and veterinary personnel Pleuropneumonie contagieuse caprine et maladie respiratoire aiguë associée à Mannheimia haemolytica des ovins et des caprins dans la région d’Afar, Ethiopie G. Shiferaw, S. Tariku, G. Ayelet & Z. Abebe Résumé En avril 2002, une enquête a porté sur un foyer de maladie respiratoire aiguë apparu chez les caprins et les ovins à Milae (Afar), en Ethiopie. Une anamnèse, des examens cliniques et post-mortem, ainsi qu’une analyse microbiologique des écouvillonnages nasaux, des lésions pleurales et des prélèvements de liquide pleural ont été réalisés dans le cadre de l’enquête. Les animaux atteints de signes cliniques de maladie présentaient une détresse respiratoire sévère et l’autopsie de deux des caprins a montré l’existence d’une pneumonie ﬁbrineuse, de séquestres pulmonaires et d’une accumulation excessive de liquide jaune Rev. sci. tech. Off. int. Epiz., 25 (3) 1161 paille dans la cavité thoracique. Mannheimia haemolytica T a été isolé à partir de 9 (6 caprins et 3 ovins) écouvillonnages nasaux (39,1 %). Mycoplasma capricolum sous-espèce capripneumoniae (Mccp) a été isolé dans les poumons et Mannheimia haemolytica T dans les lésions pulmonaires et le liquide thoracique de deux caprins autopsiés. Une espèce de mycoplasme non identifiée a été isolée dans le liquide thoracique de l’un des caprins. Pseudomonas aeruginosa a été isolé dans un séquestre pulmonaire de l’un des caprins autopsiés. Les résultats des tests de sensibilité aux antimicrobiens réalisés in vitro ont indiqué que deux (33,3 %) des six souches de M. haemolytica étaient résistantes à l’ampicilline et à la pénicilline G, trois (50 %) à la tétracycline, quatre (66,7 %) à l’oxacilline, cinq (83,3 %) à l’érythromycine, et six (100 %) à la clindamycine. Pseudomonas aeruginosa était résistant à toutes les classes d’antimicrobiens testées. Il a été conﬁrmé que la pleuropneumonie due à Mccp, et que les complications causées par M. haemolytica et l’autre espèce de mycoplasme non identiﬁée étaient à l’origine du foyer. La morbidité n’était pas associée à l’espèce animale touchée (P > 0,05) ; par contre, la mortalité était signiﬁcativement plus élevée chez les caprins que chez les ovins (P < 0,05). Mots-clés Caprin – Ethiopie – Maladie respiratoire aiguë – Mannheimia haemolytica T – Mycoplasma capricolum subsp. capripneumoniae – Ovin – Pleuropneumonie contagieuse caprine – Pseudomonas aeruginosa. Pleuroneumonía contagiosa caprina y enfermedad respiratoria aguda asociada a Mannheimia haemolytica en ovejas y cabras de la región de Afar (Etiopía) G. Shiferaw, S. Tariku, G. Ayelet & Z. Abebe Resumen Los autores describen una investigación realizada en abril de 2002 sobre un brote de enfermedad respiratoria aguda que afectó a ovinos y caprinos de la zona de Milae, Afar (Etiopía). Amén de estudiar la historia de la enfermedad, se practicaron exámenes clínicos y post-mortem y análisis microbiológicos de exudados nasales, lesiones pulmonares y muestras de líquido pleural. Los ejemplares clínicamente afectados mostraban graves trastornos respiratorios, y en dos cabras sometidas a necropsia se observó neumonía fibrinosa, secuestro pulmonar y excesiva acumulación en la cavidad torácica de un líquido amarillento. En 9 de los exudados nasales (un 39,1%), 6 de cabra y 3 de oveja, se aisló Mannheimia haemolytica T, microorganismo también presente en las lesiones pulmonares y el líquido torácico de las dos cabras objeto de necropsia, en cuyas muestras de pulmón se aisló además Mycoplasma capricolum subsp. capripneumoniae (Mccp). En el secuestro pulmonar de una de ellas se detectó asimismo la presencia de Pseudomonas aeruginosa. Por otro lado, a partir del líquido torácico de una cabra se aisló una especie no identificada 1162 Rev. sci. tech. Off. int. Epiz., 25 (3) de micoplasma. Los resultados del antibiograma pusieron de maniﬁesto que dos (33,3%) de las seis cepas aisladas de M. haemolytica eran resistentes a la ampicilina y la penicilina G, tres (50%) a la tetraciclina, cuatro (66,7%) a la oxacilina, cinco (83,3%) a la eritromicina y seis (100%) a la clindamicina. Pseudomonas aeruginosa era resistente a todas las clases de antimicrobianos utilizadas. Se conﬁrmó que el origen del brote residía en la pleuroneumonía causada por Mccp y en las complicaciones secundarias debidas a M. haemolytica y a la otra especie de micoplasma no identiﬁcada. Aunque la tasa de morbilidad no dependía de la especie afectada (P > 0,05), la mortalidad resultó signiﬁcativamente más alta en cabras que en ovejas (P < 0,05). Palabras clave Caprino – Enfermedad respiratoria aguda – Etiopía – Mannheimia haemolytica T – Mycoplasma capricolum subsp. capripneumoniae – Ovino – Pleuroneumonía contagiosa caprina – Pseudomonas aeruginosa. References 1. Armed Forces Institute of Pathology (2002). – Wednesday 8. Houshaymi R., Tekleghiorghis T., Wilsmore A.J., Miles R.J. & slide conference, 2001-2002, Conference 18, 20 February Nicholas R.A.J. (2002). – Investigation of outbreaks of 2002. CASE I – 3070 (AFIP 2694900). The Armed Forces contagious caprine pleuropneumonia in Eritrea. Trop. anim. 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