Sandra Maria Ferraz

Prevalência, quantificação e resistência a antimicrobianos de sorovares de Salmonella isolados de lingüiça frescal suína

Salmonella sp. is one of the main causes of food poisoning. In the last years, the main focus has been on beef and swine products because of both public health concerns and commercialization/exportation. This study was conducted in order to: 1) verify the prevalence of Salmonella serovars in fresh pork sausages commercialized in Lages, state of Santa Catarina and analyze its level of contamination; and 2) determine the profile of antimicrobial resistance of Salmonella sp. isolates. For this purpose, 200 samples of nine brands were collected from different commercial stores. Salmonella sp. was isolated from 27% (54). Serovar Derby accounted for the highest percentage of isolates. Only one sausage sample had a quantity of microorganism higher than 1.100 MPN.g-1. This microorganism concentration is considered enough to cause a nontyphoidal Salmonella infection. Later, the 60 strains were tested against 14 antimicrobials. Among them, 56,67% showed resistance to at least one antimicrobial agent and 20% showed multi-resistance. The Salmonella sp. prevalence in the products may be a risk for the consumer, mainly considering the high number of antimicrobial resistant isolates found in the study.

Broncopneumonia causada por Arcanobacterium pyogenes em Veado Campeiro (Ozoteceros bezearticus).

Arcanobacterium pyogenes e uma bacteria comensal das membranas mucosas do trato respiratorio e genital de varias especies de animais domesticos e selvagens. Porem, em decorrencia de estresse ou traumatismos, A. pyogenes pode se tornar um patogeno oportunista, associado a infeccoes supurativas. Estresse e um importante fator de risco para doencas em todos os animais, mas especialmente em animais silvestres nao habituados ao contato humano. Um veado-campeiro ( Ozoteceros bezearticus ) criado em area conservacionista, foi encontrado prostado e demonstrando dificuldades respiratorias. Este animal foi encaminhado ao Hospital de Clinica Veterinaria - CAV/UDESC, onde recebeu tratamento, mas, dois dias apos, morreu. O exame microscopico dos pulmoes revelou areas focalmente extensas de necrose associada a infiltrado moderado de polimorfonucleares, circundados por tecido fibroso. De acordo com a necropsia, cultivo microbiologico e sequenciamento de DNA, o agente envolvido foi classificado como A. pyogenes , caracterizando o primeiro relato de Broncopneumonia causada por A. pyogenes em Veado-Campeiro ( Ozoteceros bezearticus ) no Brasil.

Low occurrence of pathogenic Yersinia enterocolitica in pig tonsils at slaughter in Southern Brazil

Yersinia enterocolitica is a foodborne pathogen and pigs are the main reservoir of it in their tonsils. As Brazil is a large producer and exporter of pork meat and information regarding this pathogen is still quite scarce, this study aimed at evaluating the direct detection of Y. enterocolitica followed by pathogenic Y. enterocolitica (PYE) determination in tonsils of slaughtered pigs. For this purpose, 400 pig tonsils were collected from 15 farms in four federally certified slaughterhouses in Southern Brazil. Initially, samples were screened using conventional PCR targeting of the 16sRNA gene, followed by multiplex PCR (mPCR) in order to detect three virulence genes (ail, yadA, and virF) and quantitative real-time PCR (qPCR) for the detection of the ail gene. One hundred and one (25.2%) of the samples tested positive for the 16sRNA gene. However, a PYE was detected in one out of the 101 Y. enterocolitica positive samples. The three virulence genes were determined by mPCR and confirmed by partial DNA sequencing. Thus, a significant occurrence of Y. enterocolitica was observed in pig tonsils from federally inspected slaughterhouses in Brazil, although the presence of pathogenic strains was quite low.

Ocurrence of Campylobacter spp. in chilled chicken carcasses slaughtered in the west region of Santa Catarina, Brazil

Background: The thermophilic bacteria of the genus Campylobacter are important agents of alimentary gastroenteritis, called campylobacteriosis. These microorganisms multiply in temperatures ranging from 25oC to 46oC, however, low temperatures are incompatible with their multiplication. For this reason, the seasons of the year may interfere with the level of contamination by Campylobacter sp. The main sources of transmission are contaminated meat and giblets from poultry during poorly conducted slaughter operations. The disease may present itself with a different range of forms of disease: from mild signs of gastrointestinal infection to more severe cases, such as the Guillain-Barre syndrome. Material, Methods & Results: Due to the great importance of western Santa Catarina to the poultry industry, it was necessary to verify the occurrence of the pathogen in cold carcasses of broilers slaughtered in this region, and its variation through the seasons of the year. From January 2013 to February 2015 broiler carcasses were collected weekly, after the water cooling process, in slaughterhouses under Federal Inspection of the three largest microregions of western Santa Catarina in terms of number of broilers slaughtered, totaling 808 samples. The assessment of thermophilic Campylobacter was performed according to the methodology recommended by ISO 10272-1: 2006. Of the 808 samples analyzed, the frequency of isolation of thermophilic Campylobacter was 1.82% (8/440) in microregion 1, 4.95% (10/202) in microregion 2 and 13.86% (23/166) in the microregion 3, totaling 5.07% of positive samples (41/808). Comparing the microregions, it was verified that there was no significant difference (P > 0.05) between the isolation frequencies of microregions 1 and 2. However, there was a significant difference (P 0.05) between the seasons. However, it is evident the need for a longer study to evaluate the actual influence of the seasons (winter and summer) on the isolation rate of thermophilic Campylobacter in broiler carcasses shortly after the cooling process. Even though the study demonstrated low levels of thermophilic Campylobacter isolation rates in the evaluated regions, just the fact of isolating the agent already shows that there is an imminent risk to consumers, mainly due to cross-contamination of foods that will be consumed raw; therefore, higher standards of microbiological controls should be practiced in the production chain and slaughter of poultry, respecting good manufacturing practices, hygiene and handling practices within the industry.

Antimicrobial Resistance Phenotypic Profile of Isolates from Clinical Infections in Dogs

Background: Antimicrobial resistance is described as a condition in which a micro-organism is able to survive when exposed to an antimicrobial agent. The resistance rates to antimicrobials in companion animals have risen considerably. Studies of local antimicrobial susceptibility profiles are needed as well as education and warning about the use of tests for the identification and susceptibility of pathogenic bacterial strains. The aim of this study was to identify the main antimicrobial resistance in clinical samples of dogs, and to detect multidrug-resistant strains of importance to public health. Materials, Methods & Results: Bacterial pathogens of 77 dog infections were isolated and their sensitivity profile to antimicrobials was determined. One hundred bacterial isolates were identified. Of these, 61 were Gram-positive (55 Staphylococcus spp., 4 Enterococcus spp. and 2 Streptococcus spp.) and 39 Gram-negative (36 fermenters and 3 non-fermenters). Seventy-nine isolates were considered multiresistant following individual assessment of drugs, and 85 following the evaluation of classes. Only 3 were sensitive to all drugs. Four isolates were resistant to all classes and only sensitive to some antibiotics. Of the 55 samples of Staphylococcus spp., 36 (65.45%) were identified as phenotypically MRS. Two isolates of Enterococcus spp. were resistant to vancomycin (VRE). Also 66.67% (26/39) of the samples were positive for the presumptive test for ESBL. For the MRS-positive isolates detected in this study, chloramphenicol was the antimicrobial that showed superior sensitivity in 74.29% of the cases (27/36); therefore it is considered the most appropriate for treatment of this type of micro-organism. In case of aminoglycosides, when their resistance was checked in MRS isolates, all resistance percentages increased, implying a limited use of this class for such a type of multi-resistant micro-organism. Contrarily, in case of ESBL, a superior sensitivity was observed towards MRS isolates, thus making them a prime treatment choice for the infection caused by these micro-organisms. Discussion: Literature have reported a gradual increase in multidrug resistance towards antimicrobial agents in veterinary medicine over the past decades. In this study, 64% of multiresistant strains were considered of significant importance, notably MRS (36), VRE (2) and ESBL (26). The early identification of pathogens in animals has become an important step in order to minimize the transmission of antibacterial resistance. The increase in the number of multidrug-resistant bacteria in animals and humans demonstrates the need to develop and implement measures in order to monitor and control the spread of this resistance. It is possible that the increased drug resistance is linked to the constant exposure to these drugs and the subsequent selective pressure, causing the transfer of resistant genes between strains. Carbapenems and glycopeptides should be used with caution in veterinary medicine in order to prevent such processes of selection that develop resistance in micro-organisms to these two classes, which can result in cross-resistance between animals and humans and create obstacles in the treatment of patients, especially for the two drugs mentioned, since they are important for the treatment of nosocomial infections in humans. The resistance percentage towards fluoroquinolones was identified to be higher in Gram-positive isolates, particularly in MRS, which showed 75% resistance against this class (according to the CLSI, resistance to one fluoroquinolone antimicrobial agent provides resistance to other antimicrobials of this class). For ESBL isolates, the resistance was shown to be 50%. The resistance towards the fluoroquinolones and aminoglycosides class can be associated with the expression of the genes that produce ESBL.

Brucella abortus RB51 in milk of vaccinated adult cattle

The aim of this study was to evaluate the shedding of Brucella abortus in the milk of cows vaccinated with a full dose of RB51 during lactation. Eighteen cows, nine previously vaccinated with S19 as calves and nine non-vaccinated, were immunized subcutaneously with 1.3×10(10)CFU of B. abortus RB51, 30-60days after parturition. Milk samples from all animals were collected daily until day 7, and at weekly interval for the next 9 weeks after vaccination. To evaluate the shedding of B. abortus, milk samples were submitted for culture and PCR. No B. abortus was isolated from any sample tested. Only one sample, collected on first day after vaccination from a cow previously vaccinated, was faintly positive in the PCR. In conclusion, the public health hazard associated with milk consumption from cows vaccinated with RB51 in post-partum is very low, despite vaccination with the full dose and regardless of previous S19 vaccination.