Microbiological contamination in a university veterinary hospital / Contaminação microbiológica em hospital veterinário universitário

This study aimed to evaluate the microbiological contamination of the different sectors of a university veterinary hospital, the efficiency of the sanitation procedures performed, and the resistance to antimicrobials and disinfectants. Fourteen environmental samples and seven swab samples were collected from procedure tables of the different sectors. During analysis, the following microorganisms were found: bacterial species Rothia spp., coagulase-negative Staphylococcus spp., Staphylococcus aureus, and Enterococcus spp. and zygomycete fungi (could not be classified in genus due to the absence of reproductive structures) and other fungal species Cladosporium spp., Epicoccum spp., Drechslera spp., Scopulariopsis spp., and Penicillium spp. The bacterial species were submitted to a sensitivity assessment of the antimicrobials used in routine prescription. Rothia spp. and S. aureus were resistant only to erythromycin (15 µg), coagulase-negative Staphylococcus spp. were resistant to erythromycin (15 µg) and sulfazotrim (25 µg), and Enterococcus spp. were resistant to ampicillin (10 µg). For the effectiveness test of disinfectants, the products used to sanitize hospital surfaces were tested. All microorganisms in this study were resistant to 1% sodium hypochlorite solution. Rothia spp. and Enterococcus spp. were resistant to 70% ethyl alcohol. The best results were found using pure sodium hypochlorite and benzalkonium chloride, pure and diluted to 20%, which showed a bactericidal effect against all tested microorganisms. These data are relevant for knowledge of the hospital microbiota at the intersection of possible cases of hospital infections.

O objetivo desta pesquisa foi avaliar a contaminação microbiológica de diferentes setores de um hospital veterinário universitário, a eficiência dos procedimentos de higienização realizados e a resistência aos antimicrobianos das cepas encontradas. Quatorze amostras ambientais e sete amostras de swabs foram coletadas dos diferentes setores. Durante a análise foram encontradas as seguintes espécies bacterianas: Rothia spp., Staphylococcus spp. coagulase negativa, Staphylococcus aureus e Enterococcus spp.; e os seguintes fungos: zigomicetos, que não puderam ser classificados em gênero devido a ausência de estrutura reprodutiva, os demais foram Cladosporium spp., Epicoccum spp., Drechslera spp., Scopulariopsis spp. e Penicillium spp. As bactérias foram submetidas a uma avaliação de sensibilidade dos antimicrobianos utilizados prescritos na rotina. A avaliação concluiu que Rothia spp. e S. aureus foram resistentes apenas à Eritromicina (15 µg), Staphylococcus coagulase negativa resistente à Eritromicina (15 µg) e Sulfazotrim (25 µg) e Enterococcus spp. mostrou resistência à Ampicilina (10 µg). Para o teste de eficácia dos desinfetantes, foram utilizados os produtos utilizados na higienização das superfícies do hospital. O teste mostrou que todos os microrganismos encontrados no estudo eram resistentes à solução de hipoclorito de sódio diluída a 1%; Rothia spp. e Enterococcus spp. resistentes ao álcool etílico 70%. Os melhores resultados dos testes foram encontrados com hipoclorito de sódio puro e cloreto de benzalcônio puro e diluído a 20%, que apresentou efeito bactericida contra todos os microrganismos testados. Os dados encontrados foram relevantes para o conhecimento da microbiota hospitalar no cruzamento de possíveis casos de infecções hospitalares.

Efficacy of disinfectants to inactivate H1N1 influenza A virus isolated from pigs / Eficácia de desinfetantes para inativar o vírus da influenza A H1N1 isolado de suínos

The aim of this study was to access the efficacy of four disinfectants to inactivate influenza A [H1N1] 0 hour and 72 hours after disinfectant dilution. A pandemic H1N1 influenza virus isolated from a pig with respiratory disease was used to obtain inoculums containing 6.4log10 EID50/mL; 5.4log10 EID50/mL; 4.4log10 EID50/mL and 3.4log10 EID50/mL. Suspension test was composed of 400µL of viral inoculum, 100µL of organic load and 500µL of each individually diluted disinfectant and incubated for ten minutes of contact time. After a neutralizing step, each mixture was filtered on a 0.22µm membrane and 0.2mL was inoculated in six 9-day-old embryo chicken egg through allantoic route. The allantoic fluid from eggs was harvest for RT-PCR and hemagglutination test. The experiment was repeated 72 hours after disinfectant dilution. On the first assessment with fresh disinfectant, influenza virus was inactivated by oxidizing compost disinfectant and phenolic disinfectant in all virus concentrations, the quaternary ammonium compound (QAC) and glutaraldehyde association inactivated the virus up to a concentration of 5.4log10 EID50/mL. QAC disinfectant did not eliminate virus viability. Seventy-two hours after disinfectants were diluted, oxidizing compost disinfectant and QAC and glutaraldehyde association disinfectant demonstrated the same result as the evaluation with fresh disinfectant solution. Phenolic disinfectant inactivated viral inoculum up to a concentration of 5.4log10 EID50/mL. QAC had no effect on inactivating 3.4log10 EID50/ mL of influenza virus. In conclusion, three of the four disinfectants tested were effective to inactivate pandemic H1N1 influenza virus in the presence of organic load. Test result performed 72hours after disinfectant dilution suggest a decrease in the effectiveness of one disinfectant.

O objetivo deste trabalho foi avaliar a eficácia de quatro desinfetantes em inativar o vírus da influenza A [H1N1] 0-hora e 72-horas após a diluição dos produtos. Um vírus H1N1 pandêmico isolado previamente de um suíno com doença respiratória foi utilizado e foram obtidas quatro concentrações de inóculo contendo 6,4log10 EID50/mL; 5,4log10 EID50/mL; 4,4log10 EID50/mL and 3,4log10 EID50/mL. Para compor o teste em suspensão foram adicionados 400µL de inóculo viral, 100µL de matéria orgânica e 500µL de cada desinfetante diluído individualmente e a mesma foi incubada por 10 minutos. Após a etapa neutralizante, a suspensão foi filtrada em membrana 0,22µm e 0,2mL foi inoculado em seis ovos de galinha embrionados de nove dias de incubação, via rota alantóide. O fluido alantóide foi colhido após 72 horas para testes de hemaglutinação e RTPCR. O mesmo protocolo experimental foi repetido usando as soluções desinfetantes 72 horas após a diluição. O vírus da influenza foi inativado pelo composto oxidante e também pelo desinfetante fenólico em todas as concentrações virais testadas 0-hora após diluição. O desinfetante com associação de amônia quaternária e glutaraldeído inativou o vírus na concentração de até 5,4log10 EID50/mL. O desinfetante à base de amônia quaternária não inativou o vírus. Os resultados 72-horas após a diluição não diferiram quando comparado com 0-hora, exceto o desinfetante fenólico, o qual inativou o vírus da influenza somente até a concentração 5,4log10 EID50/ mL. Concluindo, três dos quatro desinfetantes testados foram efetivos ao inativar o vírus da influenza [H1N1] pandêmico na presença de matéria orgânica. Os resultados do teste com produtos diluídos após 72 horas sugerem redução da efetividade em, pelo menos, um desinfetante.

Comparative Evaluation of the Effects of Binzalkonium Chloride, Iodine, Gluteraldehyde and Hydrogen Peroxide Disinfectants against Avian Salmonellae Focusing on Genotypic Resistance Pattern of the Salmonellae Serotypes toward Benzalkonium Chloride

Using disinfectants in poultry houses is a common practice to ban the zoonotic pathogens like Salmonella. A major concern in using disinfectants is the emergence of bacteria strains that resist some disinfectants. This phenomenon is manifested in the resistance of some Salmonella serotypes against quaternary ammonium compounds. Such resistance is attributed to qacE1 gene which may be possessed by some Salmonella serotypes. This work aimed to evaluate the resistance of Salmonella serotypes (S. Typhimurium, S. Infantis and S. Entiridis) against different disinfectants (benzalkonium chloride, iodine, gluteraldehyde and hydrogen peroxide). The effect of the disinfectants were evaluated by treatment of the bacteria with different concentrations (1:100, 200 and 400) at different temperatures and periods. Bacterial count was performed before and after the treatment. PCR for presence of qacE1 gene was also performed before and after the treatment. The biocidal effect of the disinfectants found to be dependent on concentration, temperature and treatment period in addition to the type of the disinfectant. Hydrogen peroxide proved to be the most active agent followed by gluteradehyde, iodine and benzalkonium chloride. A link between the resistance against benzalkonium chloride and the existence of qacE1 gene was proven in S. Typhimurium, whether treated or not treated with benzalkonium chloride.(AU)

Comparative Evaluation of the Effects of Binzalkonium Chloride, Iodine, Gluteraldehyde and Hydrogen Peroxide Disinfectants against Avian Salmonellae Focusing on Genotypic Resistance Pattern of the Salmonellae Serotypes toward Benzalkonium Chloride

Using disinfectants in poultry houses is a common practice to ban the zoonotic pathogens like Salmonella. A major concern in using disinfectants is the emergence of bacteria strains that resist some disinfectants. This phenomenon is manifested in the resistance of some Salmonella serotypes against quaternary ammonium compounds. Such resistance is attributed to qacE1 gene which may be possessed by some Salmonella serotypes. This work aimed to evaluate the resistance of Salmonella serotypes (S. Typhimurium, S. Infantis and S. Entiridis) against different disinfectants (benzalkonium chloride, iodine, gluteraldehyde and hydrogen peroxide). The effect of the disinfectants were evaluated by treatment of the bacteria with different concentrations (1:100, 200 and 400) at different temperatures and periods. Bacterial count was performed before and after the treatment. PCR for presence of qacE1 gene was also performed before and after the treatment. The biocidal effect of the disinfectants found to be dependent on concentration, temperature and treatment period in addition to the type of the disinfectant. Hydrogen peroxide proved to be the most active agent followed by gluteradehyde, iodine and benzalkonium chloride. A link between the resistance against benzalkonium chloride and the existence of qacE1 gene was proven in S. Typhimurium, whether treated or not treated with benzalkonium chloride.

Comparison of the effect of hatchery disinfection with peracetic acid andglutaraldehydeassociated with quaternary ammonia compounds on the tracheal mucosa of one day old chicks

This study aimed at identifying lesions in the respiratory tract of chickenscaused by hatchery disinfection, performed by micro-sprinkler withperacetic acid and ammonia associated with glutaraldehyde. Theexperiment was conducted at a hatchery in Uberlândia - MG, in June2013. Three hatcheries were employed, each one using a differenttreatment process. All process had been conducted in the same room andhad the same mechanisms of temperature, humidity and ventilationcontrol. Process 1 (P1) was sprayed with a solution of peracetic acid (twoml per liter of water, total of 300 ppm); P2 was sprayed with a solution ofglutaraldehyde associated with ammonia (one ml of water per liter, total of450 and 75 ppm); and P3 was sprayed only with distilled water. At the endof 48 hours, 16 chicks per treatment process were collected at eachoutbreak to remove the trachea. Each trachea was divided into twosamples. One sample was processed for evaluation by optical microscopeand another was processed for evaluation by transmission electronmicroscope. The observation of the slides had 10 fields for evaluation, sothat all tracheal mucosa on each slide was observed for the definition ofscores according to the degree of the found lesions. At the result, there wasa significant difference only in the material evaluated by light microscopybetween chicks exposed to environmental ammonia and glutaraldehyde(P2) related to the control group (P3), considering that these chicks showedmore severe injuries, such as areas with less cilia and areas of trachealmucosa flaking. Chicks exposed to disinfection with peracetic acid inhatcheries did not show lesions of the tracheal mucosa. Therefore, whenusing the dosages in this study, peracetic acid can be used for thedisinfection of hatcheries to reduce the contamination present during theprocess, while causing less damage to the tracheal mucosa of chicks.

Comparison of the effect of hatchery disinfection with peracetic acid andglutaraldehydeassociated with quaternary ammonia compounds on the tracheal mucosa of one day old chicks

This study aimed at identifying lesions in the respiratory tract of chickenscaused by hatchery disinfection, performed by micro-sprinkler withperacetic acid and ammonia associated with glutaraldehyde. Theexperiment was conducted at a hatchery in Uberlândia - MG, in June2013. Three hatcheries were employed, each one using a differenttreatment process. All process had been conducted in the same room andhad the same mechanisms of temperature, humidity and ventilationcontrol. Process 1 (P1) was sprayed with a solution of peracetic acid (twoml per liter of water, total of 300 ppm); P2 was sprayed with a solution ofglutaraldehyde associated with ammonia (one ml of water per liter, total of450 and 75 ppm); and P3 was sprayed only with distilled water. At the endof 48 hours, 16 chicks per treatment process were collected at eachoutbreak to remove the trachea. Each trachea was divided into twosamples. One sample was processed for evaluation by optical microscopeand another was processed for evaluation by transmission electronmicroscope. The observation of the slides had 10 fields for evaluation, sothat all tracheal mucosa on each slide was observed for the definition ofscores according to the degree of the found lesions. At the result, there wasa significant difference only in the material evaluated by light microscopybetween chicks exposed to environmental ammonia and glutaraldehyde(P2) related to the control group (P3), considering that these chicks showedmore severe injuries, such as areas with less cilia and areas of trachealmucosa flaking. Chicks exposed to disinfection with peracetic acid inhatcheries did not show lesions of the tracheal mucosa. Therefore, whenusing the dosages in this study, peracetic acid can be used for thedisinfection of hatcheries to reduce the contamination present during theprocess, while causing less damage to the tracheal mucosa of chicks.(AU)

Biofilm formation by Staphylococcus aureus and Salmonella spp. under mono and dual-species conditions and their sensitivity to cetrimonium bromide, peracetic acid and sodium hypochlorite

Abstract The aim of this study was evaluated the biofilm formation by Staphylococcus aureus 4E and Salmonella spp. under mono and dual-species biofilms, onto stainless steel 316 (SS) and polypropylene B (PP), and their sensitivity to cetrimonium bromide, peracetic acid and sodium hypochlorite. The biofilms were developed by immersion of the surfaces in TSB by 10 d at 37 °C. The results showed that in monospecies biofilms the type of surface not affected the cellular density (p > 0.05). However, in dual-species biofilms on PP the adhesion of Salmonella spp. was favored, 7.61 ± 0.13 Log10 CFU/cm2, compared with monospecies biofilms onto the same surface, 5.91 ± 0.44 Log10 CFU/cm2 (p 0.05). The mono and dual-species biofilms were subjected to disinfection treatments; and the most effective disinfectant was peracetic acid (3500 ppm), reducing by more than 5 Log10 CFU/cm2, while the least effective was cetrimonium bromide. In addition, S. aureus 4E and Salmonella spp. were more resistant to the disinfectants in mono than in dual-species biofilms (p 0.05). Therefore, the interspecies interactions between S. aureus 4E and Salmonella spp. had a negative effect on the antimicrobial resistance of each microorganism, compared with the monospecies biofilms.

Biofilm formation by Staphylococcus aureus and Salmonella spp. under mono and dual-species conditions and their sensitivity to cetrimonium bromide, peracetic acid and sodium hypochlorite

The aim of this study was evaluated the biofilm formation by Staphylococcus aureus 4E and Salmonella spp. under mono and dual-species biofilms, onto stainless steel 316 (SS) and polypropylene B (PP), and their sensitivity to cetrimonium bromide, peracetic acid and sodium hypochlorite. The biofilms were developed by immersion of the surfaces in TSB by 10 d at 37 °C. The results showed that in monospecies biofilms the type of surface not affected the cellular density (p > 0.05). However, in dual-species biofilms on PP the adhesion of Salmonella spp. was favored, 7.61 ± 0.13 Log10 CFU/cm2, compared with monospecies biofilms onto the same surface, 5.91 ± 0.44 Log10 CFU/cm2 (p < 0.05). The mono and dual-species biofilms were subjected to disinfection treatments; and the most effective disinfectant was peracetic acid (3500 ppm), reducing by more than 5 Log10 CFU/cm2, while the least effective was cetrimonium bromide. In addition, S. aureus 4E and Salmonella spp. were more resistant to the disinfectants in mono than in dual-species biofilms (p < 0.05). Therefore, the interspecies interactions between S. aureus 4E and Salmonella spp. had a negative effect on the antimicrobial resistance of each microorganism, compared with the monospecies biofilms.(AU)

Use of green fluorescent protein labeled non-tuberculous mycobacteria to evaluate the activity quaternary ammonium compound disinfectants and antibiotics

Although infections with NonTuberculous Mycobacteria have become less common in AIDS patients, they are important opportunistic infections after surgical procedures, likely because they are ubiquitous and not efficiently killed by many commonly used disinfectants. In Venezuela there have recently been many non-tuberculous mycobacteria soft tissue infections after minor surgical procedures, some apparently related to the use of a commercial disinfectant based on a Quaternary Ammonium Compound. We studied the activity of this and other quaternary ammonium compounds on different non-tuberculous mycobacteria by transforming the mycobacteria with a dnaA-gfp fusion and then monitoring fluorescence to gauge the capacity of different quaternary ammonium compounds to inhibit bacterial growth. The minimum inhibitory concentration varied for the different quaternary ammonium compounds, but M. chelonae and M. abscessus were consistently more resistant than M. smegmatis, and M. terrae more resistant than M. bovis BCG.(AU)

Tipagem por MALDI-TOF MS e sensibilidade aos antimicrobianos de Prototheca spp. isolados de mastite bovina

FIDELIS, C. E. Tipagem por MALDI-TOF MS e sensibilidade aos antimicrobianos de Prototheca spp. isolados de mastite bovina. [Typing by MALDI-TOF MS and sensivity to antimicrobials of Prototheca spp. isolated from bovine mastitis]. 2021 77f. Dissertação de Mestrado (Mestrado em Ciências) Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, São Paulo, 2021. Prototheca spp. é uma microalga unicelular que pode causar infecções oportunistas em humanos e animais. Este patógeno apresenta elevada resistência a antimicrobianos convencionais e os atuais métodos de identificação de Prototheca spp. são demorados e com elevado custo. Diante disso, os objetivos do presente estudo foram avaliar: (a) o uso da técnica de MALDI-TOF MS para identificação em nível de espécie de isolados de Prototheca spp. causadores de mastite bovina; (b) a capacidade de produção de biofilme e (c) a sensibilidade in vitro de Prototheca spp. frente à polihexametileno biguanida (PHMB) e desinfetantes utilizados pré e após ordenha. Um total de 87 isolados de Prototheca spp. foram submetidos a extração de proteínas ribossomais por beads de zircônia, e posteriormente identificados por MALDI-TOF MS pelo software Biotyper suplementado com espectros de referência. Para determinação do perfil de sensibilidade in vitro, os isolados de Prototheca spp. foram submetidos a avaliação de concentração inibitória mínima (CIM) e concentração algicída mínima (CAM) pelo método de microdiluição em caldo. A capacidade de formação de biofilme foi avaliada pelo método de incubação em microplacas de fundo chato, e posteriormente, os isolados foram classificados como forte, moderado, fraco e não formador de biofilme. A MALDI-TOF MS permitiu a identificação de 73 (73/85) isolados de P. bovis e 2 (2/2) isolados de P. blaschkeae em nível de espécie. Já 12 (12/85) isolados de P. bovis foram identificados em nível de gênero. Do total dos isolados de P. bovis, 63,5% (n = 54) foram classificados como fortes, 28,2% (n = 24) moderados, e 8,2% (n = 7) fracos produtores de biofilme. Por outro lado, um isolado de P. blaschkeae foi classificado como fraco e o outro como moderado produtor de biofilme. A PHMB (CIM90: 2 µg/ml e CAM90: 4 µg/ml) e o gluconato de clorexidina (CIM90 e CAM90: 2 µg/ml), apresentaram os menores valores de CIM e CAM, seguido de dicloroisocianurato de sódio (CIM90 e CAM90: 1.400 µg/ml), hipoclorito de sódio (CIM90 e CAM90: 2.800 µg/ml), e iodo-polivinilpirrolidona (CIM90 e CAM90: 3.200 µg/ml). Concluímos que o uso da MALDI-TOF MS permite a rápida identificação de isolados de Prototheca spp. em nível de espécie. A maioria dos isolados de P. bovis apresentaram elevada capacidade de formação de biofilme. Dentre os desinfetantes, PHMB e o gluconato de clorexidina apresentaram os menores valores para inibição e inativação dos isolados de Prototheca spp.

FIDELIS, C. E. Typing by MALDI-TOF MS and sensivity to antimicrobials of Prototheca spp. isolated from bovine mastitis [Tipagem por MALDI-TOF MS e sensibilidade aos antimicrobianos de Prototheca spp. isolados de mastite bovina]. 2021 77p. Dissertação de Mestrado (Mestrado em Ciências) Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, São Paulo, 2021. Prototheca spp. is a unicellular microalga that can cause opportunistic infections in humans and animals. This pathogen has high resistance to conventional antimicrobials and the current methods of Prototheca spp. identification. are time consuming and present a high cost. Due this, the objectives of the present study were to evaluate: (a) the use of MALDI-TOF MS for identification at the species level of mastitis-causing Prototheca spp.; (b) the biofilm production capacity of Prototheca spp. isolates and (c) in vitro Prototheca spp. sensibility to polyhexamethylene biguanide (PHMB) and disinfectants used in pre and post milking. A total of 87 isolates of Prototheca spp. were submitted to ribosomal proteins extraction by zirconia beads, them, identified by MALDI-TOF MS with a Biotyper software supplemented with reference spectra. To determine the in vitro sensivity, Prototheca spp. isolates were submitted to Minimum Inhibitory Concentration (MIC) and Minimal Algicidal Concentration (MAC) using microdilution broth method. The biofilm production capacity was evaluated by microplates method, and the isolates were classified as strong, moderate, weak and non-biofilm producer. The MALDI-TOF MS allowed the identification of 73 (73/85) isolates has Prototheca bovis and 2 (2/2) isolates has Prototheca blaschkeae at species level. Although, 12 (12/85) isolates of Prototheca bovis were identified at genus level. In relation of P. bovis, 63.5% (n = 54) were classified as strong, 28.2% (n = 24) moderate, and 8.2% (n = 7) classified as weak biofilm producers. On the other hand, an isolate of P. blaschkeae was classified as weak and the other as classified has moderate biofilm producer. The PHMB (MIC90: 2 g/ml and MAC90: 4 g/ml) and chlorhexidine gluconate (MIC90 and MAC90: 2 g / ml), presented the lowest MIC and MAC values, followed by sodium dichloroisocyanurate (MIC90 and MAC90: 1.400 g / ml), sodium hypochlorite (MIC90 and MAC90: 2.800 g / ml), and iodo-polyvinylpyrrolidone (MIC90 and MAC90: 3.200 g / ml). We conclude that the use of MALDI-TOF MS allows the rapid identification of Prototheca spp. isolates at the species level. Most isolates of P. bovis presented high biofilm production capacity. Among the disinfectants, PHMB and chlorhexidine gluconate presented the lowest values for inhibition and inactivation of Prototheca spp. isolates.

The Effects of Two Different Cleaning and Disinfection Programs on Broiler Performance and Microbiological Status of Broiler Houses

The objective of this study was to investigate the influence of two cleaning and disinfection programs on broiler performance and on the microbiological status of the facilities. This trial was an observational study of comparative character. Two experiments were conducted, with 960 birds each. Both experiments were carried out in a positive-pressure broiler house. Broilers were distributed in pens equipped with a bell drinker and a tube feeder each. In the first experiment, new wood shavings were used as litter material, and in the second, reused wood shavings were used. Two treatments with16 replicates of 30 birds each were evaluated. The regular treatment consisted of dry and wet organic matter removal, followed by washing. The European treatment consisted of dry organic matter removal, humidification, washing with water under high pressure, detergent application, rinsing, and application of two combined disinfectants: glutaraldehyde 250g/L + formaldehyde 185g/L; p-chlor-m-cresol 210 g/L. Biosecurity measures were adopted during daily management tasks to prevent cross contamination between treatments. The effectiveness of the treatments was evaluated by microbiological analysis performed before and after treatment applications, as well as by broiler performance results. Live performance results were similar between both treatments when broilers were reared on new litter. When reused word-shavings were used as litter material, the European treatment promoted better broiler performance. The European treatment was more effective than the regular treatment in reducing total microbial counts in the facilities when reused wood shavings were used as litter material, and positively influenced broiler performance.

The Effects of Two Different Cleaning and Disinfection Programs on Broiler Performance and Microbiological Status of Broiler Houses

The objective of this study was to investigate the influence of two cleaning and disinfection programs on broiler performance and on the microbiological status of the facilities. This trial was an observational study of comparative character. Two experiments were conducted, with 960 birds each. Both experiments were carried out in a positive-pressure broiler house. Broilers were distributed in pens equipped with a bell drinker and a tube feeder each. In the first experiment, new wood shavings were used as litter material, and in the second, reused wood shavings were used. Two treatments with16 replicates of 30 birds each were evaluated. The regular treatment consisted of dry and wet organic matter removal, followed by washing. The European treatment consisted of dry organic matter removal, humidification, washing with water under high pressure, detergent application, rinsing, and application of two combined disinfectants: glutaraldehyde 250g/L + formaldehyde 185g/L; p-chlor-m-cresol 210 g/L. Biosecurity measures were adopted during daily management tasks to prevent cross contamination between treatments. The effectiveness of the treatments was evaluated by microbiological analysis performed before and after treatment applications, as well as by broiler performance results. Live performance results were similar between both treatments when broilers were reared on new litter. When reused word-shavings were used as litter material, the European treatment promoted better broiler performance. The European treatment was more effective than the regular treatment in reducing total microbial counts in the facilities when reused wood shavings were used as litter material, and positively influenced broiler performance.(AU)

Pesquisa de Staphylococcus aureus enterotoxigênicos formadores de biofilmes isolados de bovinos com mastite em rebanhos leiteiros e perfil de resistência frente a desinfetantes

A produção leiteira no Brasil se destaca por ser uma das atividades mais importantes para pecuária brasileira, sendo responsável pela fonte de renda de milhões de brasileiros. Entretanto, essa atividade é constantemente influenciada pela ocorrência da mastite, principalmente na forma subclínica, que ocorre nos rebanhos. Staphylococcus spp constitui o principal gênero de bactérias causadoras de mastite em bovinos. Objetivou-se com este estudo pesquisar Staphylococcus aureus enterotoxigênicos formadores de biofilmes isolados de bovinos com mastite em rebanhos leiteiros e traçar o perfil de resistência frente à desinfetantes. Foram selecionadas 10 fazendas vinculadas à uma Usina de beneficiamento de leite sob registro federal. Foi realizado o exame físico da glândula mamária e do leite dos animais e, em seguida, realizado o California Mastitis Test. Foram coletadas amostras de 960 animais para o exame microbiológico após antissepsia do óstio dos tetos com álcool 70°GL. No laboratório, alíquotas de 10 µL de leite foram semeadas em ágar sangue ovino a 5% e, em seguida, as placas incubadas a 37°C por 48 horas. Posteriormente, 213 isolados Staphylococcus spp. classificados como fortes e moderados produtores de biofilmes foram selecionados para caracterização quanto ao perfil fenotípico e presença do gene femA para identificação de S. aureus. Destes, foram confirmados 152 isolados, que foram submetidos a detecção de genes capazes de produzir biofilmes (icaA, icaD e Bap), genes que codificam as enterotoxinas (SeA, SeB, SeC, SeD, SeE), e genes relacionados a resistência (Tet(k), Vana). Testou-se a ação de desinfetantes (clorexidine e ácido láctico) utilizados na rotina de ordenha sobre o biofilme em formação e consolidado em 86 destas amostras. Em 84,16% (134/152) das amostras foram constatados o gene BAP, em 78,29% (119/152) o gene IcaD e, em apenas 1,32% (2/152) o gene IcaA. Apenas as enterotoxinas Sec em 17,76% (27/152) das amostras e See em 0,66% (1/152). Foram encontrados genes de resistência TetK em 48,68% (74/152) das amostras. Observou-se resultado satisfatório dos dois desinfetantes testados sobre o biofilme em formação, em 94,2% (81/86) dos isolados submetidos ao clorexidine e 100% dos submetidos ao ácido láctico. Entretanto, para o biofilme consolidado o percentual de ação foi bem inferior, o ácido láctico apresentou baixa eficácia sobre o biofilme já formado, com apenas 3,5% da taxa de redução, enquanto a clorexidine conseguiu reduzir 43% do biofilme consolidado. O efeito dos desinfetantes na redução da adesão de biofilmes foi bastante significativo. Sugere-se a investigação de produtos mais eficazes, que atuem tanto nas células bacterianas livres, como nos microrganismos na forma de biofilmes.

Dairy production in Brazil stands out as one of the most important activities for Brazilian livestock, being responsible for the source of income of millions of Brazilians. However, this activity is constantly influenced by the occurrence of mastitis, especially in the subclinical form, which occurs in herds. Staphylococcus spp is the main genus of mastitis-causing bacteria in cattle. The aim of this study was to investigate enterotoxigenic Staphylococcus aureus biofilm-forming isolates from bovine mastitis in dairy herds and to profile resistance against disinfectants. Ten farms linked to a federally registered Milk Processing power plant were selected. Physical examination of the mammary gland and milk of the animals was performed and then the California Mastitis Test. Samples were collected from 960 animals for microbiological examination after antisepsis of the roof ostium with 70 ° GL alcohol. In the laboratory, aliquots of 10 µl of milk were seeded on 5% sheep blood agar and then plates incubated at 37 ° C for 48 hours. Subsequently, 213 isolates Staphylococcus spp. classified as strong and moderate biofilm producers were selected for characterization regarding the phenotypic profile and presence of the femA gene for identification of S. aureus. Of these, 152 isolates were confirmed, which were subjected to detection of genes capable of producing biofilms (icaA, icaD and Bap), genes encoding enterotoxins (SeA, SeB, SeC, SeD, SeE), and resistance related genes (Tet (k), Vana). The action of disinfectants (chlorhexidine and lactic acid) used in the milking routine on biofilm in formation and consolidated in 86 of these samples was tested. In 84.16% (134/152) of the samples the BAP gene was found, in 78.29% (119/152) the IcaD gene and in only 1.32% (2/152) the IcaA gene. Only enterotoxins Sec in 17.76% (27/152) of the samples and See in 0.66% (1/152). TetK resistance genes were found in 48.68% (74/152) of the samples. Satisfactory results were observed for the two disinfectants tested on the biofilm in formation, in 94.2% (81/86) of chlorhexidine isolates and 100% of lactic acid isolates. However, for the consolidated biofilm the action percentage was much lower, the lactic acid showed low efficacy over the already formed biofilm, with only 3.5% of reduction rate, while chlorhexidine was able to reduce 43% of the consolidated biofilm. The effect of disinfectants on reducing biofilm adhesion was quite significant. Research into more effective products that act on both free bacterial cells and microorganisms in the form of biofilms is suggested.

ALGAS E LEVEDURAS ISOLADAS DE MASTITE BOVINA: IDENTIFICAÇÃO E PERFIL DE SENSIBILIDADE A ANTISSÉPTICOS E ANTIMICROBIANOS

A mastite bovina é uma das doenças mais prevalentes e impactantes na pecuária leiteira. Diferentes microrganismos estão envolvidos em sua etiologia, sendo classificados como contagiosos, quando adaptados ao interior da glândula mamária, ou ambientais, presentes normalmente no ambiente de criação dos animais. Entre os agentes ambientais, as algas e as leveduras são agentes incomuns, mas considerados emergentes. Neste trabalho, 149 cepas de leveduras e 62 de algas isoladas de casos de mastite em rebanhos bovinos de São Paulo, Minas Gerais e Paraná foram avaliadas quanto aos perfis de suscetibilidade a antimicrobianos e antissépticos, utilizando-se a técnica de concentração inibitória mínima (CIM). Adicionalmente, os isolados de leveduras foram caracterizados por meio da técnica de MALDI-TOF. Por teste de concentração inibitória mínima (CIM) não houve crescimento das algas na concentração de 4% da gentamicina, 16% amicacina e 8% polimixina B.Foram encontrados diferentes índices de inibição de crescimento das algas aos antissépticos: para o triclosano 0,25%, amônio quaternário <0,01%, peroxido de hidrogênio <0,002%, iodo 0,015, ácido peracético 0,25%, hipoclorito de sódio 0,125% e clorexina <0,018%, houve crescimento das algas nas maiores concentrações de ácido láctico e glutaraldeido. Os resultados de CIM para as leveduras foram: <0,0015% para triclosano, amônio quaternário <0,02%, peróxido de hidrogênio <0,007%, iodo 0,125%, ácido peracético 0,125%, clorexidina <0,0018 e hipoclorito de sódio na concentração de 0,125%. Estes resultados permitem confirmar a eficácia destes agentes como mecanismo de assepsia em fazendas leiterias. Houve crescimento das leveduras nas maiores concentrações do ácido láctico e o glutaraldeido. Com a técnica de identificação proteica foi traçado o perfil dos isolados identificando 6 espécies de leveduras predominando a Issatchenkia orientalis, se tratando de rebanho houve a identificação de mais de um isolado mas com predominância de espécie. Testes in vivo devem ser realizados para a comprovação da sensibilidade dos isolados aos antibióticos testados, de acordo com este estudo os resultados endossam a utilização dos antissépticos para a antissepsia de tetos (pré e pós-dipping), visando o controle e prevenção da mastite causada por estes agentes ambientais da mastite bovina. As espécies de leveduras identificadas neste estudo se assemelha a espécies já identificadas na literatura.

Bovine mastitis is one of the most prevalent and impacting diseases in dairy cattle. Different microorganisms are involved in their etiology, being classified as contagious, when adapted to the interior of the mammary gland, or environmental, normally present in the environment of animal husbandry. Among environmental agents, algae and yeasts are unusual agents, but considered emerging. In the present study, 149 yeast strains and 62 strains of algae isolated from cases of mastitis in bovine herds of São Paulo, Minas Gerais and Paraná were evaluated for the antimicrobial and antiseptic susceptibility profile, using the minimum inhibitory concentration. In addition, isolated yeasts were characterized by the MALDI-TOF technique. A minimum inhibitory concentration (MIC) test did not show growth of algae at the concentration of 4% gentamicin, 16% amikacin and 8% polymyxin B. Different rates of algae growth inhibition were observed for antiseptics: for triclosan 0.25%, quaternary ammonia <0.01%, hydrogen peroxide <0.002%, iodine 0.015, peracetic acid 0.25%, sodium hypochlorite 0.125% and chlorhexine <0.018%, there was growth of algae at the highest acid concentrations lactic acid and glutaraldehyde. The MIC results for yeast were: <0.0015% for triclosan, quaternary ammonia <0.02%, hydrogen peroxide <0.007%, iodine 0.125%, peracetic acid 0.125%, chlorhexidine <0.0018 and sodium hypochlorite in concentration of 0.125%. These results confirm the efficacy of these agents as an asepsis mechanism in dairy farms. There was growth of yeasts in the highest concentrations of lactic acid and glutaraldehyde. With the protein identification technique, the profile of the isolates was traced, identifying 6 yeast species with predominance of Issatchenkia orientalis, if in a herd there was identification of more than one isolate, but with a predominance of species. In vivo tests should be performed to confirm the sensitivity of the isolates to the antibiotics tested. According to this study, the results endorse the use of antiseptics for roof antisepsis (pre and post-immersion), aiming at the control and prevention of mastitis caused by these environmental agents of bovine mastitis. The yeast species identified in this study resemble species already identified in the literature.

Micro-organismos isolados em superfícies de mesas de exames e procedimentos descontaminadas de hospital veterinário e a inativação in vitro por desinfetantes / Microorganismos aislados en superficies de mesas de exámenes y procedimientos descontaminadas de hospital veterinario, y su inactivación in vitro por desinfectantes / Microorganisms isolated from decontaminated surfaces of exam and procedure tables of veterinary hospital and their in vitro inactivation by disinfectants

Superfícies fixas de hospitais e clínicas veterinárias podem servir como locais de infecção para micro-organismos, muitos potencialmente patogênicos comuns entre animais e seres humanos, promovendo riscos para a saúde tanto dos pacientes quanto dos profissionais veterinários. O presente estudo teve como objetivos isolar e identificar a microbiota presente em superfícies inox de mesas de exames e procedimentos de áreas do setor de pequenos animais de um hospital veterinário de ensino, sobre as quais rotineiramente é procedida a descontaminação (desinfecção sem prévia limpeza), e verificar in vitro a capacidade de inativação microbiana dos grupos químicos desinfetantes ácido peracético, iodóforo, hipoclorito de sódio, quaternário de amônio, fenol sintético, clorhexidina e álcool. Quinze coletas, em três dias de meses diferentes, procederam-se com swabs rolados sobre as superfícies, de onde foram isolados Staphylococcus spp. coagulase (+) e (-), Sphingomonas paucimobilis, Streptococcus spp. (não grupo D), Enterobacter spp., Acinetobacter Iwoffii, Bacillus cereus, Pseudomonas spp., Micrococcus spp., Enterococcus spp., Cocobacilo não fermentador, Bacillus spp., Citrobacter spp. e Candida guilliermondii. O método da avaliação desinfetante foi o de diluição, pela técnica de suspensão microbiana, composta por três pools de bactérias (um por dia de coleta) e uma cultura de levedura, em três concentrações dos desinfetantes nos tempos de contato 1, 5 e 10 minutos. Observou-se que todos os desinfetantes inativaram todos os micro-organismos, tendo quaternário de amônio, fenol sintético, clorhexidina e álcool inativado nas menores concentrações e tempos de contato testados. Concluiu-se que nas superfícies das mesas de todos os ambientes puderam ser isolados micro-organismos, muitos destes de importância à saúde humana e animal; os testes in vitro evidenciaram que todos os grupos químicos avaliados podem ser usados no procedimento de desinfecção para inativar os isolados; a descontaminação, adotada como único procedimento de higienização de rotina nas superfícies onde os veterinários e seus pacientes entram em contato, pareceu não ser segura para proteger a saúde dos animais e dos profissionais de saúde animal.

Inanimate surfaces of hospitals and veterinary clinics can be a source of infection by microorganisms, many potentially pathogenic common between animals and humans, promoting the health risks of both patients and veterinary professionals. The aims of the present study were to isolate and identify the microbiota found on stainless steel surfaces of exam and procedure tables of the small animal ward of a veterinary teaching hospital, on which decontamination (disinfection without prior cleaning) is carried out on a routine basis, and to check in vitro inactivation by chemical disinfectants. Fifteen collections in three days of different months, we proceeded with swabs rolled over the surfaces of which were isolated coagulase-positive and coagulase-negative Staphylococcus spp., Sphingomonas paucimobilis, (non-group D) Streptococcus spp., Enterobacter spp., Acinetobacter Iwoffii, Bacillus cereus, Pseudomonas spp., Micrococcus spp., Enterococcus spp., non-fermenting coccobacilli, Bacillus spp., Citrobacter spp. and Candida guilliermondii. The inactivation capacity of peracetic acid, iodophor, sodium hypochlorite, quaternary ammonium, synthetic phenol, chlorhexidine and alcohol was assessed. The dilution method by microbial suspension test was performed using an experimental design consisting of three pools of bacteria (one per collection day) and a yeast culture at three disinfectant concentrations at 1, 5 and 10 minutes. All disinfectants inactivate all microorganisms, with quaternary ammonium, synthetic phenol, chlorhexidine and alcohol inactivated at lower concentration and contact times. It may be concluded that microorganisms - many of them deleterious to human and animal health - could be isolated from all of the sampled surfaces; the in vitro tests showed that all of the assessed chemicals can be used to inactivate the isolates; decontamination, as a unique hygiene routine procedure used on surfaces in direct contact with health professionals and patients, did not seem to safely protect the health of animals and health professionals.

Superficies fijas de hospitales y clínicas veterinarias pueden servir de fuente de infección por microorganismos, muchos potencialmente patogénicos comunes entre animales y seres humanos, promoviendo riesgos para la salud tanto de los pacientes como de los profesionales veterinarios. El presente estudio tuvo como objetivos aislar e identificar la microbiota presente en superficies inox de mesas de exámenes y procedimientos de áreas del sector de pequeños animales de un hospital veterinario de enseñanza, sobre las cuales rutinariamente es procedida la descontaminación (desinfección sin previa limpieza), y verificar in vitro la capacidad de inactivación microbiana de los grupos químicos desinfectantes ácido peracético, yodóforo, hipoclorito de sodio, cuaternario de amonio, fenol sintético, clorhexidina y alcohol. Fueron realizadas quince colectas, en tres días de meses diferentes, con swabs rodados sobre las superficies, de donde fueron aislados Staphylococcus spp. coagulasa (+) y (-), Sphingomonas paucimobilis, Streptococcus spp. (no grupo D), Enterobacter spp., Acinetobacter Iwoffii, Bacillus cereus, Pseudomonas spp., Micrococcus spp., Enterococcus spp., Cocobacilo no fermentador, Bacillus spp., Citrobacter spp. y Candida guilliermondii. El método de la evaluación desinfectante fue el de dilución, por la técnica de suspensión microbiana, compuesta por tres pools de bacterias (uno por día de colecta) e una cultura de levadura, en tres concentraciones de los desinfectantes en los tiempos de contacto 1, 5 y 10 minutos. Fue observado que todos los desinfectantes inactivaron todos los microorganismos, teniendo el cuaternario de amonio, fenol sintético, clorhexidina y alcohol inactivado con las menores concentraciones y tiempos de contacto. Se concluye que en las superficies de las mesas de todos los ambientes pudieron aislarse microorganismos, muchos de los cuales de importancia para la salud humana y animal; las pruebas in vitro evidenciaron que todos los grupos químicos evaluados pueden ser usados en el procedimiento desinfección para inactivar los aislados; la descontaminación, adoptada como único procedimiento de higienización de rutina en las superficies donde los veterinarios y sus pacientes entran en contacto, pareció no ser seguro para proteger la salud de los animales y de los profesionales de salud animal.

Efeito antifúngico de agentes químicos sobre leveduras com potencial patogênico isoladas de ambiente hospitalar veterinário / Antifungal effect of chemical agents in yeasts with pathogenic potential isolated from veterinary hospital environment

Os ambientes hospitalares podem albergar micro-organismos patogênicos e oportunistas, capazes de infectar, particu- larmente, os indivíduos imunossuprimidos. O processo de limpeza e desinfecção assume importância capital para o controle de tais doenças. O presente trabalho avaliou a suscetibilidade de leveduras isoladas de superfícies de ambiente hospitalar veterinário frente a quatro desinfetantes/antissépticos comumente utilizados na rotina de desinfecção. O teste de microdiluição em caldo foi realizado com 24 isolados leveduriformes frente ao hipoclorito de sódio 4%, cloreto de benzalcônico 2%, clorexidina-cetrimida 6,6% e derivado de cloro-fenol 3%. A clorexidina-cetrimida, cloreto de ben- zalcônio e derivado de cloro-fenol foram eficazes em todos os isolados com concentração inibitória mínima e concen- tração fungicida inferiores à concentração recomendada pelo fabricante. Por outro lado, a ação fungicida do hipoclorito de sódio em 79,1% dos isolados testados foi obtida na concentração recomendada pelo fabricante, com desempenho inferior aos demais desinfetantes avaliados.(AU)

Hospital environments can have pathogens and opportunistic pathogens, important for immunocompromising individuals. The process of cleaning and disinfection constitutes an important measure for the control of these diseases. This study evaluated the sensitivity of yeasts isolated from surfaces of nosocomial veterinary environment to four disinfectants/antiseptics used in the routine of disinfection. The test of broth microdilution was carried in 24isolates of yeasts against 4% sodium hypochlorite, 2% benzalkonium chloride, 6.6% chlorexidine-cetrimide and 3% chloro-phenol derivate. Chlorexidine-cetrimide, benzalkonium chloride and chloro-phenol derivate were efficient in all isolates with minimal inhibitory concentration and minimal fungicide concentration lower than the concentra- tion recommended by manufacturer. By other hand, fungicide action of the sodium hypochlorite in the concentration recommended by the manufacturer was verified in 79.1% of the isolated tested, with the lower performance of than the others evaluated disinfectants.(AU)

Reduction of Aeromonas hidrophyla biofilm on stainless stell surface by essential oils

This study demonstrates the possibility of using sanitizing detergents based on natural products for the elimination and/or reduction of Aeromonas hydrophila biofilm formed on stainless steel surfaces. The goal of this work was to determine the reduction effect of sanitizing detergents containing essential oils of Thymus vulgaris (thyme) and Cymbopogon citratus (lemongrass) on biofilm formed by A. hydrophila on AISI 304 stainless steel coupons, using UHT skimmed milk as substratum. There was adhesion and biofilm formation by A. hydrophila at 28 ºC, presenting 7.60 log cfu.cm-2 after the fourth day of cultivation. There was no significant difference between the lemongrass treatment and that of the thyme oil (p < 0.05). However, both treatments significantly reduced the biofilm, differing significantly from the NaOH control (p > 0.05). The treatment with lemongrass solution reduced the biofilm by 4.51 log cfu cm-2 at 25 ºC. The thyme detergent also reduced the number of cfu cm-2 by 3.84 log cycles at 25 ºC. The use of the lemongrass and thyme solutions efficiently reduced the A. hydrophila biofilm.(AU)

Avaliação da contaminação microbiana em produtos desinfetantes de uso geral / Microbial contamination in household disinfectant products

Em vista de um estudo desenvolvido no Setor de Saneantes do Instituto Nacional de Controle de Qualidade em Saúde da Fundação Oswaldo Cruz, referente à avaliação da atividade antimicrobiana de desinfetantes, no presente trabalho foram analisados produtos desinfetantes de uso geral disponíveis no mercado brasileiro. Os desinfetantes foram coletados aleatoriamente, dos quais três (produtos A, B e C), apresentaram contaminação microbiana. Para efetuar o isolamento e a identificação dos microrganismos contaminantes foram utilizados o aparelho Vitek® 2, a amplificação e o sequenciamento do gene rRNA16S. A análise realizada por meio de Vitek® 2 revelou a presença das bactérias Serratia marcescens e Achromobacter xylosoxidans, respectivamente, nos produtos A e B. No produto C foram detectadas Aeromonas salmonicida pelo Vitek® 2 e Burkholderia lata pela técnica de amplificação da reação em cadeia da polimerase.(AU)

On account of a study developed in Sanitation Sector at the National Institute of Quality Control in Healthof Oswaldo Cruz Foundation, concerning the evaluation of antimicrobial activity of disinfectants, the present investigation analyzed disinfectant products of general use which are available in the Brazilian market. Of the disinfectants randomly collected, three of them (products A, B and C) showed microbial contamination. The contaminant microorganisms isolation and identification were performed by using the equipment Vitek® 2, and the rRNA 16S amplification and sequencing were done. Vitek® 2 analysis revealed the occurrence of Serratia marcescens and Achromobacter xylosoxidans in the products A and B, respectively. Aeromonas salmonicida was detected by Vitek® 2, and Burkholderia lata was identified by means of amplification technique through polymerase chain reaction in the product C.(AU)

Activity of disinfectants and biofilm production of Corynebacterium pseudotuberculosis / Atividade de desinfetantes e produção de biofilme em Corynebacterium pseudotuberculosis

To verify the occurrence of caseous lymphadenitis in sheep and goats on farms of Pernambuco, Brazil, and in animals slaughtered in two Brazilian cities (Petrolina/PE and Juazeiro/BA), and to characterize the susceptibility profile of Corynebacterium pseudotuberculosis to disinfectants and antimicrobials, and its relationship with biofilm production were the objectives of this study. 398 samples were tested for sensitivity to antimicrobial drugs, disinfectants, and biofilm production. Among the 108 samples collected on the properties, 75% were positive for C. pseudotuberculosis. Slaughterhouse samples indicated an occurrence of caseous lymphadenitis in 15.66% and 6.31% for animals slaughtered in Petrolina and Juazeiro respectively. With respect to antimicrobials, the sensitivity obtained was 100% for florfenicol and tetracycline; 99.25% for enrofloxacin, ciprofloxacin and lincomycin; 98.99% for cephalothin; 98.74% for norfloxacin and sulfazotrim; 97.74% for gentamicin; 94.22% for ampicillin; 91.71% for amoxicillin; 91.21% for penicillin G; 89.19% for neomycin and 0% for novobiocin. In analyzes with disinfectants, the efficiency for chlorhexidine was 100%, 97.20% for quaternary ammonium, 87.40% for chlorine and 84.40% for iodine. 75% of the isolates were weak or non-biofilm producers. For the consolidated biofilm, found that iodine decreased biofilm formation in 13 isolates and quaternary ammonia in 11 isolates. The reduction of the biofilm formation was observed for iodine and quaternary ammonium in consolidated biofilm formation in 33% and 28% of the isolates, respectively. The results of this study highlight the importance of establishing measures to prevent and control the disease. (AU)

Verificar a ocorrência de linfadenite caseosa de ovinos e caprinos em fazendas de Pernambuco, no Brasil e em animais abatidos em duas cidades brasileiras (Petrolina/PE e Juazeiro/BA), caracterizar o perfil de suscetibilidade de Corynebacgerium pseudotuberculosis a desinfetantes e a antimicrobianos e analisar sua relação com a produção de biofilme foram os objetivos deste estudo. 398 amostras foram testadas para a sensibilidade aos medicamentos antimicrobianos, desinfetantes e produção de biofilme. Entre as 108 amostras coletadas nas propriedades, 75% foram positivas para C. pseudotuberculosis. Amostras do matadouro indicaram a ocorrência de linfadenite caseosa em 15,66% e 6,31% para animais abatidos em Petrolina (PE) e Juazeiro (BA), respectivamente. Com relação aos antimicrobianos, a sensibilidade obtida foi de 100% para florfenicol e tetraciclina, 99,25% para a enrofloxacina, ciprofloxacina e lincomicina; 98,99% para cefalotina; 98,74% para norfloxacina e sulfazotrim; 97,74% para gentamicina; 94,22% para ampicilina, 91,71% para amoxicilina, 91,21% para a penicilina G, 89,19% para a neomicina e 0% para novobiocina. Nas análises com desinfetantes, a eficiência para a clorexidina foi de 100%, 97,20% para amônia quaternária, 87,40% para o cloro e 84,40% para o iodo. 75% dos isolados foram fracos produtores de biofilme. Para o biofilme consolidado, observou-se que o iodo diminuiu a formação de biofilme em 13 isolados e a amônia quaternária em 11 isolados. A redução da formação de biofilme foi observada no biofilme consolidado, para iodo e amônia quaternária, em 33% e 28% das amostras, respectivamente. Os resultados deste estudo destacam a importância de se estabelecer medidas para prevenir e controlar a doença. (AU)

Activity of disinfectants against foodborne pathogens in suspension and adhered to stainless steel surfaces

The purpose of this study was to investigate and compare the efficacy of various disinfectants on planktonic cells and biofilm cells of Listeria monocytogenes, Staphylococcus aureus and Escherichia coli. Numbers of viable biofilm cells decreased after treatment with all tested disinfectants (iodine, biguanide, quaternary ammonium compounds, peracetic acid and sodium hypochlorite). Sodium hypochlorite was the most effective disinfectant against biofilm cells, while biguanide was the least effective. Scanning electron microscopy observations revealed that cells adhered on stainless steel surface after treatment with the disinfectants. No viable planktonic cells were observed after treatment with the same disinfectants. Based on our findings, we concluded that biofilm cells might be more resistant to disinfectants than plancktonic cells.