Abstract in English:
ABSTRACT.- Peixoto R.M., França C.A., Souza Júnior A.F., Veschi J.L.A. & Costa M.M. 2010. [Etiology and profile of antimicrobial sensitivity of bacteria from small ruminant mastitis and relationship of diagnostic techniques.] Etiologia e perfil de sensibilidade antimicrobiana dos isolados da mastite em pequenos ruminantes e concordância de técnicas empregadas no diagnóstico. Pesquisa Veterinária Brasileira 30(9):734-740. Campus Ciências Agrárias, Universidade Federal do Vale do São Francisco, Rodov. BR 407 Km 12, Lote 543, Projeto de Irrigação Senador Nilo Coelho s/n, Petrolina, PE 56300-990, Brazil. E-mail: mateus.costa@univasf.edu.br
Mastitis is an inflammation of mammary gland, that are important in milking breed as well in meat ones. It is associated with serious reduction in milk production and quality, lambs weight gain reduction and mortality The goal of this work was determine the major etiologic agents of goat and sheep mastitis, as well as antimicrobial drug–resistance patterns and the agreement between two different diagnostic tools. We visit 25 goat, sheep, and goat and sheep farms in Pernambuco and Bahia State, and a total of 439 goats and 76 sheep milk samples were collected. To diagnose of small ruminant mastitis were compared two tests: Milk culture and California Mastitis Test (CMT). The bacterial drug-resistance pattern was determined by Kirby Bauer test. Staphylococcus spp. was the most frequent bacteria isolated from goat and sheep mastitis cases. Streptococcus spp., Corynebacterium spp. and gram-negative bacilli were isolated. It was possible to observe the high sensitivity to antimicrobial drugs in all tested bacteria, being the lower sensitivity percentage determined to nalidixic acid. Considering caprine mastitis diagnostic the comparative analysis between microbiologic culture and shown a concordance degree of K=0,17, although to ovine species these value was K=0,22. The use of CMT to subclinical mastitis diagnostic in goat and ewes must be associated to milk bacterial culture.
Abstract in Portuguese:
RESUMO.- Peixoto R.M., França C.A., Souza Júnior A.F., Veschi J.L.A. & Costa M.M. 2010. [Etiology and profile of antimicrobial sensitivity of bacteria from small ruminant mastitis and relationship of diagnostic techniques.] Etiologia e perfil de sensibilidade antimicrobiana dos isolados da mastite em pequenos ruminantes e concordância de técnicas empregadas no diagnóstico. Pesquisa Veterinária Brasileira 30(9):734-740. Campus Ciências Agrárias, Universidade Federal do Vale do São Francisco, Rodov. BR 407 Km 12, Lote 543, Projeto de Irrigação Senador Nilo Coelho s/n, Petrolina, PE 56300-990, Brazil. E-mail: mateus.costa@univasf.edu.br
A mastite é a inflamação da glândula mamária que acomete raças de aptidão leiteira como também aquelas voltadas para produção de carne. Esta enfermidade ocasiona sérias alterações na produção de leite e na sua qualidade, redução no ganho de peso e mortalidade de cordeiros. O presente estudo teve por objetivo conhecer os principais agentes causadores de mastite em ovinos e caprinos, bem como a sua susceptibilidade aos agentes antimicrobianos, além de avaliar o grau de concordância entre testes diagnósticos. Foram visitadas 25 propriedades durante a realização do experimento, sendo criatórios de caprinos, ovinos e rebanhos mistos, nos estados de Pernambuco e Bahia. Coletou-se leite de 439 caprinos e 76 ovinos. Foi realizada lactocultura, o California Mastitis Test (CMT) e o teste de sensibilidade aos antimicrobianos. Além disso, determinou-se o grau de concordância entre os testes diagnósticos empregados. Foi constatada uma maior freqüência de Staphylococcus spp. nos casos de mastite em caprinos e ovinos, sendo observado ainda, isolados de Streptococcus spp., Corynebacterium spp. e bacilos gram negativos (BGN). Os isolados apresentaram alta sensibilidade aos antimicrobianos testados, sendo o menor percentual de sensibilidade observado para o ácido nalidíxico. Em relação ao diagnóstico da mastite caprina, a análise comparativa entre o exame microbiológico e o CMT demonstrou um grau de concordância igual a K=0,17, enquanto que para a espécie ovina, este valor foi de K=0,22. A utilização do CMT para o diagnóstico da mastite subclínica em cabras e ovelhas deverá ser associado à técnica da lactocultura.
Abstract in English:
ABSTRACT.- Abreu D.L.C., Franco R.M., Nascimento E.R., Pereira V.L.A., Alves F.M.X. & Almeida J.F. 2010. [Profile of antimicrobial resistance and detection of iss gene by the polymerase chain reaction in the typification of pathogenic Escherichia coli in meat type quails under sanitary inspection.] Perfil de sensibilidade antimicrobiana e detecção do gene iss pela reação em cadeia da polimerase na tipificação de Escherichia coli patogênica em codornas de corte sob inspeção sanitária. Pesquisa Veterinária Brasileira 30(5):406-410. Departamento de Tecnologia de Alimentos, Universidade Federal Fluminense, Niterói, RJ 24320-340, Brazil. E-mail: dayseabreu@predialnet.com.br
The pathogenicity of Escherichia coli strains is partially related to the expression of virulence factors genes, present in genetic elements called plasmids. APEC strains responsible for diseases in birds may present the iss gene which increases the resistance of E. coli strains to the lityc effect of the host’s serum, besides resistance to several antimicrobials. This study was conduced in order to detect E. coli in tracheae of meat-type quails and to evaluate, by the presence of the iss gene and the profile of antimicrobial susceptibility, the pathogenic potential of the isolated samples for birds and humans. One hundred and eighty tracheae of quails were collected for detection of E. coli, antimicrobial sensitivity tests, and for polymerase chain reaction (PCR), for detection of iss gene. From the examined quails, 8.9 % (16/180) were positive for E. coli, from which 20 strains of this bacterium were obtained. Most of them were resistant to Tetracycline (16/20), followed by Ceftadizime (13/20) and Nalidixic-acid (12/20) and only one isolate was resistant to Amoxicillin. The detection of iss gene occurred in 55% (11/20) of the isolates, indicating that these strains had the potential to be pathogenic not only for quails, but also for other kinds of birds, other animals and even human beings that would be in contact with these E. coli isolates.
Abstract in Portuguese:
RESUMO.- Abreu D.L.C., Franco R.M., Nascimento E.R., Pereira V.L.A., Alves F.M.X. & Almeida J.F. 2010. [Profile of antimicrobial resistance and detection of iss gene by the polymerase chain reaction in the typification of pathogenic Escherichia coli in meat type quails under sanitary inspection.] Perfil de sensibilidade antimicrobiana e detecção do gene iss pela reação em cadeia da polimerase na tipificação de Escherichia coli patogênica em codornas de corte sob inspeção sanitária. Pesquisa Veterinária Brasileira 30(5):406-410. Departamento de Tecnologia de Alimentos, Universidade Federal Fluminense, Niterói, RJ 24320-340, Brazil. E-mail: dayseabreu@predialnet.com.br
A patogenicidade das cepas de Escherichia coli está relacionada à expressão de fatores de virulência encontrados em elementos genéticos denominados plasmídios. O patotipo APEC, responsável por diferentes tipos de doenças em aves, pode apresentar o gene iss que aumenta a resistência das cepas de E. coli aos efeitos líticos do soro, além da resistência a diversos antimicrobianos. Este estudo foi conduzido para detectar E. coli em traquéias de codornas destinadas ao abate e avaliar, pela presença do gene iss e o perfil de susceptibilidade antimicrobiana, o potencial patogênico para aves e humanos dos isolados obtidos. Foram coletadas 180 traquéias de codornas para detecção de E. coli, determinação do perfil de resistência a agentes antimicrobianos e posterior detecção, por reação em cadeia da polimerase (PCR), do gene iss. Das traquéias analisadas, 8,9 % (16/180) foram positivas para E. coli, sendo obtidos 20 isolados deste agente. A maioria dos isolados foi resistente à Tetraciclina (16/20), seguida pela Ceftazidima (13/20) e Ácido Nalidíxico (12/20), sendo apenas um resistente à Amoxicilina. A detecção do gene iss ocorreu em 55% (11/20) dos isolados. A presença do gene iss e a resistência a múltiplos antimicrobianos dos isolados obtidos neste estudo pode indicar um possível potencial patogênico das cepas de E. coli tanto para codornas quanto para outros tipos de aves e animais e mesmo para o ser humano que fique em contato com as mesmas.
Abstract in English:
ABSTRACT.- Medeiros E.S., Mota R.A., Santos M.V., Freitas M.F.L. Pinheiro Jr J.W. & Teles J.A. A. 2009. [In vitro antimicrobial sensitivity to Staphylococcus spp. isolates from dairy cows with subclinical mastitis.] Sensibilidade antimicrobiana in vitro de Staphylococcus spp. isoladas do leite de vacas com mastite subclínica. Pesquisa Veterinária Brasileira 29(7):569-574. Departamento de Medicina Veterinária, Universidade Federal Rural de Pernambuco, Rua Dom Manoel de Medeiros s/n, Dois Irmãos, Recife, PE 51171-900, Brazil. E-mail: rinaldo.mota@hotmail.com
The objective of the investigation was to evaluate the in vitro antimicrobial sensibility of 291 isolates of Staphylococcus spp., taken from the mammary glands of dairy cows with subclinical mastitis in the regions of Metropolitan Recife (A), Agreste (B) and Zona da Mata (C) in the state of Pernambuco, Brazil. From the 291 isolates, 170 (58.4%) were identified as negative coagulase Staphylococcus (SCN), 84 (28.9%) as Staphylococcus aureus, and 37 (12.7%) as positive coagulase Staphylococcus (SCP). To study sensitivity to antimicrobials, the diffusion in disks method was used with 16 antimicrobial drugs commonly employed in the treatment of mastitis. The most efficient antibiotic in vitro was the combination of neomicine + bacitracine + tetracycline with percentages of 98.4%, 99.3%, and 89.7% for the A, B, and C regions, respectively. The least efficient was ampicillin, which was resistant to 56.5% of the isolates taken from region A, 72.8% from region B, and 71.8% from region C. These results indicate the need for periodic testing of sensitivity in vitro, as these variations can compromise the treatment of animals as well as control programs for bovine mastitis caused by Staphylococcus spp.
Abstract in Portuguese:
ABSTRACT.- Medeiros E.S., Mota R.A., Santos M.V., Freitas M.F.L. Pinheiro Jr J.W. & Teles J.A. A. 2009. [In vitro antimicrobial sensitivity to Staphylococcus spp. isolates from dairy cows with subclinical mastitis.] Sensibilidade antimicrobiana in vitro de Staphylococcus spp. isoladas do leite de vacas com mastite subclínica. Pesquisa Veterinária Brasileira 29(7):569-574. Departamento de Medicina Veterinária, Universidade Federal Rural de Pernambuco, Rua Dom Manoel de Medeiros s/n, Dois Irmãos, Recife, PE 51171-900, Brazil. E-mail: rinaldo.mota@hotmail.com
The objective of the investigation was to evaluate the in vitro antimicrobial sensibility of 291 isolates of Staphylococcus spp., taken from the mammary glands of dairy cows with subclinical mastitis in the regions of Metropolitan Recife (A), Agreste (B) and Zona da Mata (C) in the state of Pernambuco, Brazil. From the 291 isolates, 170 (58.4%) were identified as negative coagulase Staphylococcus (SCN), 84 (28.9%) as Staphylococcus aureus, and 37 (12.7%) as positive coagulase Staphylococcus (SCP). To study sensitivity to antimicrobials, the diffusion in disks method was used with 16 antimicrobial drugs commonly employed in the treatment of mastitis. The most efficient antibiotic in vitro was the combination of neomicine + bacitracine + tetracycline with percentages of 98.4%, 99.3%, and 89.7% for the A, B, and C regions, respectively. The least efficient was ampicillin, which was resistant to 56.5% of the isolates taken from region A, 72.8% from region B, and 71.8% from region C. These results indicate the need for periodic testing of sensitivity in vitro, as these variations can compromise the treatment of animals as well as control programs for bovine mastitis caused by Staphylococcus spp.
Abstract in English:
ABSTRACT.- Coelho S.M.O., Reinoso E., Pereira I.A., Soares L.C., Demo M., Bogni C & Souza M.M.S. 2009. Virulence factors and antimicrobial resistance in Staphylo-coccus aureus isolated from bovine mastitis in Rio de Janeiro. Pesquisa Veterinária Brasileira 29(5):369-374. Departamento de Microbiologia e Imunologia Veterinária, Instituto de Veterinária, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ 23890-000, Brazil. E-mail: miliane@ufrrj.br
The study was conducted to characterize pheno-genotypically the virulence factors and resistance pattern of Staphylococcus aureus isolates from milk samples of cows with subclinical mastitis. All hemolytic isolates presented beta-hemolysin, and 38% of the non-hemolytic isolates were able to express hemolysins in the presence of a beta-hemolytic strain. The amplification of the coa-gene displayed four different size polymorphisms with about 400 bp, 600 bp, 700 bp and 900 bp. The spaA gene that encodes the IgG-binding region of protein A revealed sizes of 700 bp and 900 bp. The amplification of region X from spaA yielded a single amplicon for each isolate with the prevalent amplicon size being of 180 bp. Amplification of sae gene yielded an amplicon size of 920 bp in 71% of the isolates. Antibiotic resistance pattern revealed that 42% S. aureus were susceptible to all antimicrobials tested. Seven different antibiotic patterns were observed. Our results indicated that 47% and 25% of S. aureus strains exhibited resistance to penicillin and oxacillin respectively. All oxacillin-resistant isolates were mecA-positive.
Abstract in Portuguese:
ABSTRACT.- Coelho S.M.O., Reinoso E., Pereira I.A., Soares L.C., Demo M., Bogni C & Souza M.M.S. 2009. Virulence factors and antimicrobial resistance in Staphylo-coccus aureus isolated from bovine mastitis in Rio de Janeiro. Pesquisa Veterinária Brasileira 29(5):369-374. Departamento de Microbiologia e Imunologia Veterinária, Instituto de Veterinária, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ 23890-000, Brazil. E-mail: miliane@ufrrj.br
The study was conducted to characterize pheno-genotypically the virulence factors and resistance pattern of Staphylococcus aureus isolates from milk samples of cows with subclinical mastitis. All hemolytic isolates presented beta-hemolysin, and 38% of the non-hemolytic isolates were able to express hemolysins in the presence of a beta-hemolytic strain. The amplification of the coa-gene displayed four different size polymorphisms with about 400 bp, 600 bp, 700 bp and 900 bp. The spaA gene that encodes the IgG-binding region of protein A revealed sizes of 700 bp and 900 bp. The amplification of region X from spaA yielded a single amplicon for each isolate with the prevalent amplicon size being of 180 bp. Amplification of sae gene yielded an amplicon size of 920 bp in 71% of the isolates. Antibiotic resistance pattern revealed that 42% S. aureus were susceptible to all antimicrobials tested. Seven different antibiotic patterns were observed. Our results indicated that 47% and 25% of S. aureus strains exhibited resistance to penicillin and oxacillin respectively. All oxacillin-resistant isolates were mecA-positive.
Abstract in English:
ABSTRACT.- Costa M.M., Peixoto R.M., Boijink C.L., Castagna L., Meurer F., & Vargas A.C. 2008. [Antimicrobial sensibility of bacterial isolates from jundiá (Rhamdia quelen).] Sensibilidade antimicrobiana de bactérias isoladas de jundiá (Rhamdia quelen). Pesquisa Veterinária Brasileira 28(10):477-480. Universidade Federal do Vale do São Francisco, Rua da Simpatia 179, Petrolina, PE 56304-440, Brazil. E-mail: mateus.costa@univasf.edu.br
Aiming the evaluation of sensitivity profiles of pathogen bacteria responsible for fish diseases, 51 bacterial isolates from Jundiá (Rhamdia quelen) belonging to the genus Acinetobacter spp. (8), Aeromonas spp. (15), Edwardsiella spp. (2), Enterobacter spp. (2), Klebsiella spp. (1), Plesiomonas spp. (5), Pseudomonas spp. (1), Staphylococcus spp. (11), and Vibrio spp. (6), were tested against antimicrobial agents used for treatment of bacterial fish diseases. All samples were processed at the Laboratory of Bacteriology, Department of Preventive Veterinary Medicine, UFSM. From 51 bacteria isolated from jundiá fishes (Rhamdia quelen) 51 (100%) were sensitive to gentamycin, 49 (96,08%) to sulphazotrin, 47(92,16%) to chloramphenicol, 43 (84,31%) to tetracylin, 43 (84,31%) to naldixic acid, 31 (60,78%) to nitrofurantoin, 22 (43,14%) to erytromycin, 22 (43,14%) to ampicillin, 15 (29,41%) spiramycin, 13 (25,50%) to cholystin, and 5 (3%) to penicillin G. With exception of an isolate of Staphylococcus spp., the bacteria analyzed in the present study were resistant to one or more antimicrobial agents tested. Knowledge of the sensitivity profile of bacteria involved in infectious processes in fish will allow rational antimicrobial treatment that will contribute to the control of fish diseases in Rhamdia quelen without causing great risks to public health and the environment.
Abstract in Portuguese:
ABSTRACT.- Costa M.M., Peixoto R.M., Boijink C.L., Castagna L., Meurer F., & Vargas A.C. 2008. [Antimicrobial sensibility of bacterial isolates from jundiá (Rhamdia quelen).] Sensibilidade antimicrobiana de bactérias isoladas de jundiá (Rhamdia quelen). Pesquisa Veterinária Brasileira 28(10):477-480. Universidade Federal do Vale do São Francisco, Rua da Simpatia 179, Petrolina, PE 56304-440, Brazil. E-mail: mateus.costa@univasf.edu.br
Aiming the evaluation of sensitivity profiles of pathogen bacteria responsible for fish diseases, 51 bacterial isolates from Jundiá (Rhamdia quelen) belonging to the genus Acinetobacter spp. (8), Aeromonas spp. (15), Edwardsiella spp. (2), Enterobacter spp. (2), Klebsiella spp. (1), Plesiomonas spp. (5), Pseudomonas spp. (1), Staphylococcus spp. (11), and Vibrio spp. (6), were tested against antimicrobial agents used for treatment of bacterial fish diseases. All samples were processed at the Laboratory of Bacteriology, Department of Preventive Veterinary Medicine, UFSM. From 51 bacteria isolated from jundiá fishes (Rhamdia quelen) 51 (100%) were sensitive to gentamycin, 49 (96,08%) to sulphazotrin, 47(92,16%) to chloramphenicol, 43 (84,31%) to tetracylin, 43 (84,31%) to naldixic acid, 31 (60,78%) to nitrofurantoin, 22 (43,14%) to erytromycin, 22 (43,14%) to ampicillin, 15 (29,41%) spiramycin, 13 (25,50%) to cholystin, and 5 (3%) to penicillin G. With exception of an isolate of Staphylococcus spp., the bacteria analyzed in the present study were resistant to one or more antimicrobial agents tested. Knowledge of the sensitivity profile of bacteria involved in infectious processes in fish will allow rational antimicrobial treatment that will contribute to the control of fish diseases in Rhamdia quelen without causing great risks to public health and the environment.
Abstract in English:
Vargas A.C., Costa M.M., Groff A.C.M., Viana L.R., Krewer C.C., Spricigo D.A. & Kirinus J.K. 2005. [Antimicrobial susceptibility of Campylobacter fetus subsp. venerealis isolated from cattle.] Susceptibilidade antimicrobiana de Campylobacter fetus subsp. venerealis isolado de bovinos. Pesquisa Veterinária Brasileira 25(1):1-3. Laboratório de Bacteriologia do Departamento de Medicina Veterinária Preventiva, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil. E-mail: agueda@ccr.ufsm.br
Venereal campylobacteriosis is associated with infection of Campylobacter fetus subsp. fetus and Campylobacter fetus subsp. venerealis. The etiological agent is transmitted by natural bull breeding or artificial insemination using contaminated semen. The present study aimed to determine the in vitro susceptibility of C. fetus subsp. venerealis isolates to antimicrobial drugs generally used in clinical and semen treatment. Reference strains of C. fetus subsp. fetus and C. fetus subsp. venerealis and 21 C. fetus isolates were tested. The susceptibility test was performed by using the modified Kirby-Bauer diffusion disc method. C. fetus subsp. fetus reference strain was resistant to lincomycin and penicillin. C. fetus subsp. venerealis was susceptible to all antimicrobial tested, with exception to C.C. KrewerDnalidixic acid. C. fetus subsp. venerealis samples were sensible to amikacin, ampicillin, cefalotin, streptomycin, gentamycin, penicillin and tetracycline. Drug resistance was observed on 42.86% of lincomycin, 4,76 % of enrofloxacin, and 100% to nalidixic acid. In addition 4.76% of the isolates showed intermediate susceptibility to enrofloxacin, neomycin, polimixin B and 9.52% to lincomycin. The susceptibility of C. fetus isolates to antimicrobial drugs commonly used in clinical and semen treatment was demonstrated.
Abstract in Portuguese:
Vargas A.C., Costa M.M., Groff A.C.M., Viana L.R., Krewer C.C., Spricigo D.A. & Kirinus J.K. 2005. [Antimicrobial susceptibility of Campylobacter fetus subsp. venerealis isolated from cattle.] Susceptibilidade antimicrobiana de Campylobacter fetus subsp. venerealis isolado de bovinos. Pesquisa Veterinária Brasileira 25(1):1-3. Laboratório de Bacteriologia do Departamento de Medicina Veterinária Preventiva, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil. E-mail: agueda@ccr.ufsm.br
Venereal campylobacteriosis is associated with infection of Campylobacter fetus subsp. fetus and Campylobacter fetus subsp. venerealis. The etiological agent is transmitted by natural bull breeding or artificial insemination using contaminated semen. The present study aimed to determine the in vitro susceptibility of C. fetus subsp. venerealis isolates to antimicrobial drugs generally used in clinical and semen treatment. Reference strains of C. fetus subsp. fetus and C. fetus subsp. venerealis and 21 C. fetus isolates were tested. The susceptibility test was performed by using the modified Kirby-Bauer diffusion disc method. C. fetus subsp. fetus reference strain was resistant to lincomycin and penicillin. C. fetus subsp. venerealis was susceptible to all antimicrobial tested, with exception to C.C. KrewerDnalidixic acid. C. fetus subsp. venerealis samples were sensible to amikacin, ampicillin, cefalotin, streptomycin, gentamycin, penicillin and tetracycline. Drug resistance was observed on 42.86% of lincomycin, 4,76 % of enrofloxacin, and 100% to nalidixic acid. In addition 4.76% of the isolates showed intermediate susceptibility to enrofloxacin, neomycin, polimixin B and 9.52% to lincomycin. The susceptibility of C. fetus isolates to antimicrobial drugs commonly used in clinical and semen treatment was demonstrated.
Abstract in English:
Attempts were made to study a possible involvement of bacteria in the periodontal lesions of "Cara inchada" in cattle (CI). Corynebacterium pyogenes could be isolated from all of 23 CI-positive bovines and from the tissue samples of 1 of 22 CI-negative controls. Bacteroides mekzninogenicus occurred together with C. pyogenes in all CI-lesions and only in 1 of the CI-negative tissue samples. Bacteroides bivius was cultivated from 13 and Fusobacterium nucleatum from 9 of the 23 CI-positive, but from none of the CI-negative animals. Actinomyces israelii occurred more frequently in the samples of the CI-negative than those of the CI-positive animals. The isolated bacteria were consistently susceptible in vitro to penicillin G, tetracycline and erythromycin. Repeated intragingival injections of C. pyogenes alone and together with B. melaninogenicus into 5 calves and 2 young sheep did not produce progressive periodontal lesions. However, 2 of the calves developed distinct and 2 slight retractions of the gingiva near the sites of injections. This did not indicate a primary role of the isolated bacteria in "Cara inchada" of cattle, but could suggest some bacterial involvement in the development of the periodontal lesions.
Abstract in Portuguese:
Foi conduzido um estudo para investigar o possível envolvimento de agentes bacterianos em lesões de "cara inchada" em bovinos (CI). Corynebacterium pyogenes foi isolado das lesões peridentárias de todos os 23 bezerros com CI necropsiados para fins de estudo bacteriológico, e somente 1 das 22 biópsias da gengiva feitas em bezerros negativos para a doença. Bacteroides melaninogenicus ocorreu, junto com C. pyogenes, em todas as lesões peridentárias, mas somente em 1 das biópsias dos animais sadios de controle. Bacteroides bivius foi isolado de 13 e Fusobacterium nucleatum de 9 dos 23 bezerros com CI, mas de nenhum dos animais de controle. Actinomyces israelii ocorreu mais freqüentemente nas biópsias da gengiva dos bezerros de controle do que nas lesões peridentárias dos animais com CI. As bactérias isoladas mostraram-se, in vitro, sempre sensíveis à penicilina G, à tetraciclina e à eritromicina. Repetidas inoculações intra-gengivais de C. pyogenes, realizadas em 5 bezerros e 2 cordeiros, e de C. pyogenes junto com B. melaninogenicus, nã'o causaram lesões peridentárias progressivas; mas em 2 bezerros observaram-se, na região das inoculações, retração moderada e, em 2 outros, retração leve da gengiva. Estes resultados não indicam que as bactérias isoladas tenham papel primário na etiologiada "cara inchada" dos bovinos, mas parecem sugerir algum envolvimento destas bactérias na patogênese das lesões peridentárias.