Antimicrobial susceptibility patterns of Brazilian Haemophilus parasuis field isolates / Perfil de susceptibilidade antimicrobiana de isolados clínicos brasileiros de Haemophilus parasuis

Haemophilus parasuis is the etiological agent of Glässer's disease (GD), an ubiquitous infection of swine characterized by systemic fibrinous polyserositis, polyarthritis and meningitis. Intensive use of antimicrobial agents in swine husbandries during the last years triggered the development of antibiotic resistances in bacterial pathogens. Thus, regular susceptibility testing is crucial to ensure efficacy of different antimicrobial agents to this porcine pathogen. In this study, 50 clinical isolates from South Brazilian pig herds were characterized and analyzed for their susceptibility to commonly used antibiotic. The identification and typing of clinical isolates was carried out by a modified indirect hemagglutination assay combined with a multiplex PCR. The susceptibility of each isolate was analyzed by broth microdilution method against a panel of 21 antimicrobial compounds. We found that field isolates are highly resistance to gentamycin, bacitracin, lincomycin and tiamulin, but sensitive to ampicillin, clindamycin, neomycin, penicillin, danofloxacin and enrofloxacin. Furthermore, an individual susceptibility analysis indicated that enrofloxacin is effective to treat clinical isolates with the exception of those classified as serovar 1. The results presented here firstly demonstrate the susceptibility of Brazilian clinical isolates of H. parasuis to antimicrobials widely used by swine veterinary practitioners and strengthen the need to perform susceptibility test prior to antibiotic therapy during GD outbreaks. In addition, because only six antimicrobial drugs (28.6%) were found effective against field isolates, a continuous surveillance of the susceptibility profile should be of major concern to the swine industry.(AU)

Haemophilus parasuis é o agente etiológico da doença de Glässer (GD), um processo infeccioso que acomete suínos e que se caracteriza por poliserosites fibrinosas sistêmicas, poliartrites e meningites. O uso intensivo de agentes antimicrobianos na produção de suínos, durante os últimos anos, tem disparado a seleção de cepas bacterianas resistentes a antibióticos. Desta maneira, a avaliação rotineira de susceptibilidade torna-se crucial para assegurar a correta seleção de um antimicrobiano eficaz contra este patógeno. Neste estudo, analisou-se a susceptibilidade antimicrobiana de 50 isolados clínicos de H. parasuis procedentes de granjas localizadas na região sul do Brasil. A identificação e tipificação dos isolados clínicos foi realizada através de uma PCR multiplex combinada com o teste de hemaglutinação indireta modificada. A susceptibilidade de cada isolado foi analisada pelo método de microdiluição em caldo utilizando-se um painel composto por 21 agentes antimicrobianos. Os resultados deste estudo indicam que as cepas clínicas de H. parasuis apresentam alta resistência à gentamicina, bacitracina, lincomicina e tiamulina, no entanto, são susceptíveis a ampicilina, clindamicina, neomicina, penicilina, enrofloxacina e danofloxacina. A análise de susceptibilidade realizada dentro de cada grupo de cepas de um mesmo sorovar indicou que a enrofloxacina é o antibiótico mais efetivo para tratar todos isolados clínicos com exceção daqueles pertencentes ao sorovar 1. Em termos gerais, neste trabalho, demonstra-se o perfil de susceptibilidade de isolados clínicos de H. parasuis aos antimicrobianos comumente utilizados pelos médicos veterinários especialistas em suínos, e reforça-se a necessidade da realização de testes de susceptibilidade antes do início da terapia com antibióticos durante surtos de DG. Além disso, como somente seis antimicrobianos (28.6%) foram efetivos contra os isolados clínicos, uma vigilância contínua do perfil de susceptibilidade aos antimicrobianos deve ser de grande preocupação para a indústria de suínos.(AU)

Antimicrobianos para o controle da enteropatia proliferativa suína / Antimicrobial use for the control of porcine proliferative enteropathy

A enteropatia proliferativa suína (EPS), causada pela bactéria Lawsonia intracellularis, causa perdas econômicas importantes mundialmente, devido à diarréia e baixa taxa de crescimento de suínos na recria (forma crônica) e à morte súbita de animais de terminação e reposição (forma aguda). Programas de controle têm sido focalizados na medicação com antibióticos na ração. Essencialmente, a eficiência de um antimicrobiano pode ser testada in vitro ou in vivo. Testes in vivo podem ser desenvolvidos utilizando-se animais natural ou experimentalmente infectados. No caso de infecção experimental, o inóculo pode ser preparado com culturas puras de L. intracellularis ou com homogenado de mucosa intestinal de leitões enfermos. O uso de antimicrobianos tem-se mostrado eficiente em reduzir os sinais clínicos da EPS, resultando em melhor performance dos animais tratados em relação aos não-medicados e na redução da eliminação fecal da bactéria e da extensão e severidade das lesões macroscópicas. A maioria dos fármacos eficientes que são discutidas no texto são dos grupos dos macrolídeos, das tetraciclinas, lincosamidas e pleuromutilinas. Todos esses fármacos agem bloqueando a síntese protéica de bactérias.

Porcine proliferative enteropathy (PPE), caused by the bacterium Lawsonia intracellularis, causes serious economic losses worldwide due to diarrhea and poor growth rate medication in young growing pigs (chronic disease form) and sudden death in finisher and replacement pigs (acute hemorrhagic form). Typical control programs have focused on antibiotics. Essentially, the effectiveness of an antimicrobial can be tested in vitro or in vivo. In vivo test can be developed with natural or experimentally infected pigs. In tests that the animals are experimentally challenged, the inoculation is done with pure culture of L. intracellularis or intestinal mucosal homogenate of pig with PPE. Antimicrobial use have been shown to be effective in reducing the clinical signs of PPE and to result in better performance in treated pigs than in untreated animals. In addition, it decreases fecal shedding and the severity of gross lesions. The most efficient antimicrobial groups of drugs discussed in this manuscript are macrolides, tetracyclines, lincosamides and pleuromutilins. All of them act by blocking bacterial protein synthesis.

Therapeutic effect of bee venom in sows with hypogalactia syndrome postpartum

The objective of this study was to determine the clincotherapeutic effect of whole bee venom in hypogalactic sows postpartum. Sows after parturition were assigned to treated and nontreated control groups. In the treated group, 22 sows were bee acupunctured once a day for 3 consecutive days. Honeybees (Apis mellifera L.) for bee acupuncture were about 15 days after metamorphosis. One live bee was used to sting the acupoints known as Yang-ming (ST-18, 1.5 cm lateral to the base of the last 2 pairs of teats) and Jiao-chao (GV-1, at the indentation between the base of tail and the anus). In the control group, 20 sows were intramuscularly injected with a standard dosage of penicillin G (400,000 IU/head) once a day for 3 consecutive days. At post-treatment, 85.0% of the drug-treated control and 90.9% of the bee venomtreated group recovered from hypogalactia syndrome. The advantages of apitherapy were that the patients did not have stress because they were not restrained for a long period. The result suggested that apitherapy using bee venom is an effective treatment for sows with hypogalactia syndrome postpartum.

Sensibilidade antimicrobiana de amostras de Escherichia coli isoladas de leitöes lactentes com diarréia / Antimicrobial sensitivity Escherichia coli of strains isolated from suckling piglets with diarrhoea

A Escherichia coli é o principal agente infeccioso envolvido nas diarréias dos leitöes lactentes, sendo usada terapia através de drogas para controlar esta doença. Foram estudadas 224 cepas de Escherichia coli isoladas de leitöes lactentes com diarréia em relaçäo à sensibilidade antimicrobiana. Os resultados mostram alta resistência a três antimicrobianos na inibiçäo do crescimento de cepas de Escherichia coli, isoladas de leitöes lactentes, com diarréia, no sudoeste do Paraná.

Schistosoma japonicum in the pig: the influence of age on the host/parasite relationship.

The current study sought to elucidate a possible association between age and susceptibility to a primary infection with Schistosoma japonicum in pigs. Sixteen Landrace/Yorkshire crossbred specific pathogen-free pigs in three different age groups (group A-C), aged approximately 7, 24 and 37 weeks at the beginning of the experiment, were infected by intramuscular injections of 1,000, 1,500 or 2,400 cercariae, respectively. Fecal egg counts were obtained twice weekly from six to eight weeks post infection (wpi), and the pigs were killed 11 wpi. The number of worms collected were counted and sexed subsequent to perfusion. Tissue egg counts were estimated on samples from the liver. The worm recoveries for group A, B and C were 3.2%, 8.1% and 3.8%, respectively. No differences were observed between the male/female ratios of the three groups. The fecundity parameters, ie, fecal egg counts per mature female and liver egg counts per mature female, showed no significant differences between the three age groups. The results did not indicate any difference in susceptibility between the different age-groups of pigs to a primary infection with S. japonicum.