Diagnosis of mycobacteria in bovine milk: an overview

Tuberculosis remains as the world’s biggest threat. In 2014, human tuberculosis ranked as a major infectious disease by the first time, overcoming HIV death rates. Bovine tuberculosis is a chronic disease of global distribution that affects animals and can be transmitted to humans by the consumption of raw milk, representing a serious public health concern. Despite the efforts of different countries to control and eradicate bovine tuberculosis, the high negative economic impact on meat and milk production chains remains, given the decreased production efficiency (approximately 25%), the high number of condemned carcasses, and increased animal culling rates. This scenario has motivated the establishment of official programs based on regulations and diagnostic procedures. Although Mycobacterium tuberculosis and Mycobacterium bovis are the major pathogenic species to humans and bovines, respectively, nontuberculous mycobacteria within the Mycobacterium genus have become increasingly important in recent decades due to human infections, including the ones that occur in immunocompetent people. Diagnosis of mycobacteria can be performed by microbiological culture from tissue samples (lymph nodes, lungs) and secretions (sputum, milk). In general, these pathogens demand special nutrient requirements for isolation/growth, and the use of selective and rich culture media. Indeed, within these genera, mycobacteria are classified as either fast- or slow-growth microorganisms. Regarding the latter ones, incubation times can vary from 45 to 90 days. Although microbiological culture is still considered the gold standard method for diagnosis, molecular approaches have been increasingly used. We describe here an overview of the diagnosis of Mycobacterium species in bovine milk

Nontuberculous mycobacteria in milk from positive cows in the intradermal comparative cervical tuberculin test: implications for human tuberculosis infections

Although the tuberculin test represents the main in vivo diagnostic method used in the control and eradication of bovine tuberculosis, few studies have focused on the identification of mycobacteria in the milk from cows positive to the tuberculin test. The aim of this study was to identify Mycobacterium species in milk samples from cows positive to the comparative intradermal test. Milk samples from 142 cows positive to the comparative intradermal test carried out in 4,766 animals were aseptically collected, cultivated on Lowenstein-Jensen and Stonebrink media and incubated for up to 90 days. Colonies compatible with mycobacteria were stained by Ziehl-Neelsen to detect acid-fast bacilli, while to confirm the Mycobacterium genus, conventional PCR was performed. Fourteen mycobacterial strains were isolated from 12 cows (8.4%). The hsp65 gene sequencing identified M. engbaekii (n=5), M. arupense (n=4), M. nonchromogenicum (n=3), and M. heraklionense (n=2) species belong to the Mycobacterium terrae complex. Despite the absence of M. tuberculosis complex species in the milk samples, identification of these mycobacteria highlights the risk of pathogen transmission from bovines to humans throughout milk or dairy products, since many of mycobacterial species described here have been reported in pulmonary and extrapulmonary diseases both in immunocompetent and immunocompromised people

Fundamentos e aplicações da medicina veterinária forense no bem-estar de bovinos leiteiros: Revisão

Este artigo tem o objetivo de discutir o papel da medicina veterinária forense com ênfase no bem-estar de bovinos leiteiros. Cresce a consciência mundial em torno da maneira como manejamos e tratamos os bovinos leiteiros durante o ciclo de produção, sendo o bem-estar animal o maior desafio para alcançar sistemas produtivos. Casos de suspeita de crueldade, abuso ou negligência contra animais confrontam profissionais e suas equipes com dilemas éticos, os quais envolvem preocupações econômicas, de gestão e jurídicas. A cada dia a mídia revela com maior frequência informações sobre a forma como os animais de produção são tratados. Perante este cenário houve grande interesse dos consumidores em geral sobre produtos oriundos de animais criados em regime de manejo humanizado. Neste contexto, surge com força a medicina veterinária forense como ciência embasada cientificamente na criminalística, na ética, no direito e no bem-estar dos animais de produção. Longe de constituir apenas como uma especialidade a medicina veterinária forense vem trazendo um novo cenário exercendo uma visão multidisciplinar e subsidiando um novo paradigma na cadeia de produção animal. A descrição deste artigo deixou claro nova visão do sistema de exploração dos bovinos leiteiros onde deve prevalecer relação de atitudes cotidianas que sejam consideradas as necessidades comportamentais, fisiológicas, reprodutivas e sanitárias, levando em conta à ética, o respeito e a compaixão, que favoreçam equilíbrio entre produção e bem-estar animal

Índice de resistência múltipla aos antimicrobianos, concentração inibitória mínima e ESBL fenotípica em linhagens de Proteus mirabilis e Proteus vulgaris isoladas de diferentes afecções em animais domésticos

Proteus spp. are opportunistic multidrug resistant enterobacteria associated with diverse clinical diseases in domestic animals. However, Proteus infections in domestic animals are often misdiagnosed or considered contaminants in microbiological cultures rather than a primary agent of disease. Descriptions of Proteus infections in domestic animals are typically restricted to case reports, retrospective studies, or surveillance of other microorganisms. The present study investigated multiple antibiotic resistance indices, minimum inhibitory concentrations (MICs), and ESBL production in 73 strains of Proteus mirabilis (n = 69) and Proteus vulgaris (n = 4) isolated from domestic animals with various clinical manifestations. In dogs, the pathogen was most commonly associated with cystitis (48.21), enteritis (21.42%), otitis (14.29%), and conjunctivitis (3.57%). In bovines, the microorganism was predominant in cases of enteritis (22.22%), abscess (11.11%), otitis (11.11%), omphalitis (11.11%), and peritonitis (11.11%), and in organ fragments (11.11%). In equines (50.0%) and cats (100.0%), diarrhea was the main clinical sign. In vitro standard disk diffusion assay showed that the most effective antimicrobials against the isolates were imipenem (98.63), norfloxacin (95.89), amikacin (95.89), levofloxacin (90.41), ceftriaxone (87.64), and florfenicol (87.67). In contrast, the isolates commonly showed resistance to novobiocin (95.89), azithromycin (57.53), and trimethropim/sulfamethoxazole (39.73). Among the 73 isolates, the efficacy of amoxicillin/clavulanic acid, gentamicin, ceftriaxone, and ciprofloxacin according to MICs was 87.67%, 86.30%, 84.93%, and 82.19%, respectively. The MIC50 values of amoxicillin/clavulanic acid, ceftriaxone, ciprofloxacin, and gentamicin were, respectively, 1.0, 0.004, 0.03, and 1.0 µg/mL. Thirty-three strains (45.21%) showed a antimicrobial multiple resistance index of ? 0.3. Multidrug resistance profiles of isolates were observed most frequently in dogs (n = 25; 75.76%), particularly in those with cystitis (n = 13; 52.0%), followed by bovines (n = 4; 12.12%), equines (n = 2; 6.06%), and cats (n = 2; 6.06%). Two (2.7%) strains, obtained from canine skin and feces, were diagnosed phenotypically as ESBL-producers. Here, we observed the diversity of Proteus infections in domestic animals. The presence of multidrug-resistant isolates and ESBL-producers reinforces the need for appropriate antimicrobial use and in vitro antimicrobial tests to support therapy.Proteus spp. são enterobactérias oportunistas, multirresistentes aos antimicrobianos, associadas a diversas infecções em animais domésticos. No entanto, as infecções por Proteus em animais de produção e de companhia são negligenciadas ou, por vezes, o patógeno é considerado “contaminante”, ainda que em infecções como agente primário. Os registros de infecções por Proteus sp. em animais domésticos estão restritos aos relatos de casos, estudos retrospectivos ou compondo estudos com outros micro-organismos. O presente estudo investigou o índice de resistência múltipla (IRMA) e a concentração inibitória mínima (CIM) de 73 Proteus mirabilis (n=69) e Proteus vulgaris (n=4) a diferentes antimicrobianos, bem com a produção fenotípica de ESBL, em isolados obtidos de várias manifestações clínicas em animais domésticos. Em cães, o micro-organismo foi identificado predominantemente em casos de cistite (48,21%), enterite (21,42%), otite (14,29%) e conjuntivite (3,57%). Nos bovinos, o agente foi isolado predominantemente de casos enterite (22,22%), abscesso (11,11%), otite (11,11%), onfalite (11,11%), peritonite (11,11%), metrite (11,11%) e em fragmento de órgão (11,11%). Nos equinos (50,0%) e felinos (100,0%) o micro-organismo foi isolado principalmente de enterite. A maior sensibilidade dos isolados no teste “in vitro” de difusão com discos foi observada para imipeném (98,63%), norfloxacino (95,89%), amicacina (95,89%), levofloxacino (90,41%), ceftriaxona (87,64%) e florfenicol (87,67%), enquanto a maior resistência das linhagens foi observada para novobiocina (95,89%), azitromicina (57,53%) e sulfametoxazole-trimetropim (39,73%). Dentre as 73 linhagens, a eficácia da amoxicilina/ácido clavulânico, gentamicina, ceftriaxona e ciprofloxacino utilizando o teste de CIM foi, respectivamente, 87,67%, 86,30%, 84,93% e 82,19%. A CIM50 para amoxicilina/ácido clavulânico, ceftriaxona, ciprofloxaicno e gentamicina foi, respectivamente, 1,0 µg/mL, 0,004 µg/mL, 0,03 µg/mL e 1,0 µg/mL. O índice de resistência múltipla aos antimicrobianos (IRMA ? 0,3) foi observado em 33 (45,21%) linhagens, variando entre 0,1 a 1. Entre os isolados com perfis de multirresistência, a maior ocorrência foi observada em cães (n=25; 75,76%), particularmente em animais com cistite (n=13; 52,0%), seguido pelos bovinos (n=4; 12,12%), equinos (n=2; 6,06%) e felinos (n=2; 6,06%). A presença fenotípica de ESBL foi identificada em dois (2,7%) isolados obtidos de dermatite e fezes de cães. Infere-se a diversidade de infecções causadas por Proteus em animais domésticos, a presença de isolados ESBL-positivos e multirresistentes aos antimicrobianos, reforçando a importância da instituição do tratamento do patógeno com respaldo em testes “in vitro” de sensibilidade microbiana e do uso racional de antimicrobianos no tratamento de infecções em animais domésticos

Successful therapy in unusual generalized Dermatophilus congolensis infection in a calf based on modified in vitro disk diffusion test

<div><p>ABSTRACT: Bovine dermatophilosis is a dermatitis characterized by typical focal or localized lesions with “paintbrush” aspect and occasionally as disseminated cutaneous disease. We report the case of a one-year-old Nelore female with history of chronic cutaneous disseminated lesions that appeared immediately after a rainfall period. Serous to purulent exudates, hair with tufted appearance, hyperkeratotic, non-pruritic, hardened, yellowish to brown, and coalescent crusty lesions were observed distributed all over its body. Removal of the crusts revealed ulcerated or hemorrhagic areas, with irregular elevated crusts like “paintbrush”. Microbiological diagnosis enabled the identification of a microorganism, the Dermatophilus congolensis. Despite disseminated and chronic lesions, we obtained a successful therapy with parenteral therapy using long-acting tetracycline based on modified in vitro disk diffusion test. The present report highlights success therapy in uncommon generalized bovine dermatophilosis with selection of first-choice drugs based on modified in vitro susceptibility test, and need of responsible use of antimicrobials in livestock.</p></div