Acid resistance of Salmonella Typhimurium ATCC 14028 after desiccation stress during peanut storage / Avaliação da resistência ácida de Salmonella Typhimurium ATCC 14028 após o estresse dessecativo durante o armazenamento de amendoim

Salmonella is a relevant pathogen, which causes foodborne outbreaks associated with both high and low moisture foods (LMF). This study evaluated the effect of previous desiccation stress on the acid resistance of S. Typhimurium ATCC 14028 using blanched peanut kernels as an LMF model. Salmonella was recovered from the peanut samples throughout 180 days of blanched peanut kernels storage at 28 ºC. During this period two death rates were verified, 0.04 log cfu/g/day in the first 30 days and 0.007 log cfu/g/day between 30 and180 days.Regarding acid resistance, there was no difference (P > 0.05) in the Salmonella growth/death kinetics between the undesiccated sample (TSB)and the cells recovered from peanut samples over 180 days of storage after 4 h at pHs 3.0, 3.5, 4.5 and 7.2. The average growth rate observed for pH 7.2 was 0.44 log cfu/ml/h. At pH 4.5, the Salmonella counts did not change significantly over 4 h. In contrast, Salmonella populations declined by 0.14 to 0.29 log cfu/ml/h at pH 3.5. At pH 3.0 declines were estimated to be 0.65 log cfu/ml/h for the undesiccated sample and 2.07 log cfu/ml/h for Salmonella recovered from peanuts stored for 120 days. Therefore, our data indicated that desiccation stress caused during the peanut storagedid not influence the Salmonella acid resistance.

Em alimentos de baixa umidade (LMF), o primeiro desafio encontrado por patógenos como a Salmonella é o estresse de dessecação. Neste estudo, o efeito prévio do estresse de dessecação sobre a resistência ácida de S. Typhimurium ATCC 14028 foi avaliado utilizando amendoim blancheado como um modelo de LMF. Salmonella foi recuperada das amostras de amendoim após 180 dias de estocagem a 28 ºC. Durante este período foram verificadas duas taxas de mortalidade, 0,04 log ufc/g/dia nos primeiros 30 dias e 0,007 log ufc/g/dia entre 30 e 180 dias. Com relação à resistência ácida, não houve diferença (P > 0,05) na cinética de crescimento/morte de Salmonella entre a amostra sem estresse dessecativo (TSB) e as amostras de amendoim após 4 h em pHs 3,0, 3,5, 4,5 e 7,2. A taxa média de crescimento observada para o pH 7,2 foi de 0,44 log cfu/ml/h. No pH 4,5, a contagem de Salmonella não mudou significativamente durante 4 h. Em contraste, a população de Salmonella diminuiu de 0,14 a 0,29 log cfu/ml/h no pH 3,5. No pH 3,0, a queda foi estimada em 0,65 log cfu/ml/h para a amostra sem estresse dessecativo e 2,07 log cfu/ml/h para a Salmonella recuperada das amostras de amendoim estocadas por 120 dias. Portanto, nossos dados indicaram que o estresse dessecativo causado durante a estocagem do amendoim não influenciou a resistência ácida de Salmonella.

Portrayal of Punica granatum L. peel extract through High Performance Liquid Chromatography and antimicrobial activity evaluation

Abstract Increasing trend in antimicrobial resistance and failure of chemically synthesized antibiotics lead to discover alternative methods for the treatment of bacterial infections. Various medicinal plants are in use traditionally and their active compounds can be further applied for treatment of bacterial diseases. This study was designed to determine the antibacterial activity of Punica granatum (P. granatum L.) (pomegranate) peel extract against Enterobacteriaceae [Escherichia coli (E. coli), Salmonella Typhimurium (S. Typhimurium) and Shigella Dysenteriae (S. Dysenteriae)] and gram-positive bacterium [Staphylococcus aureus (Staph aureus)]. Methanolic extract of P. granatum L. peel was prepared by Soxhlet apparatus method. Total flavonoid and phenolic contents from the extract were determined by High Performance Liquid Chromatography (HPLC). The antibacterial activity of P. granatum L. peel extract was evaluated through agar well diffusion method. HPLC showed the range of phenolics (gallic acid, caffeic acid, benzoic acid, cinnamic acid) and flavonoid compounds. The chemical structures of flavonoid and phenolics found in the methanolic extract of P. granatum L. peel have been reported for the first time. The methanolic peel extract (50 ul) of yellow P. granatum L. showed 26, 10, 10 and 9mm zones of inhibition (ZOI) against S. aureus, S. Typhimurium, S. Dysenteriae and E. coli, respectively. The methanolic extract of red P. granatum L. (100 ul) showed 27, 8, 12 and 15 mm ZOI against Staph. aureus, S. Typhimurium, S. Dysenteriae and E. coli, respectively. Highest ZOI was observed against Staph. aureus. Many of the bacteria studied in the present work may cause serious gastrointestinal infections, which can lead to hemorrhagic diarrhea in children. These infections can be life-threatening to young children and the elderly. There is an incentive to find alternative control measures, such as plant and herbal extracts, especially in lesser-developed countries where traditional antibiotics may not be readily available.

Resumo A tendência crescente na resistência antimicrobiana e na falha dos antibióticos sintetizados quimicamente leva à descoberta de métodos alternativos para o tratamento de infecções bacterianas. Várias plantas medicinais estão em uso tradicionalmente e seus compostos ativos podem ser posteriormente aplicados para o tratamento de doenças bacterianas. Este estudo foi desenhado para determinar a atividade antibacteriana do extrato de casca de Punica granatum (P. granatum L.) (romã) contra Enterobacteriaceae [Escherichia coli (E. coli), Salmonella Typhimurium (S. Typhimurium) e Shigella Dysenteriae (S. Dysenteriae) ] e bactéria gram-positiva [Staphylococcus aureus (Staph aureus)]. O extrato metanólico da casca de P. granatum L. foi preparado pelo método do aparelho de Soxhlet. O conteúdo total de flavonoides e fenólicos do extrato foi determinado por cromatografia líquida de alta eficiência (HPLC). A atividade antibacteriana do extrato da casca de P. granatum L. foi avaliada através do método de difusão em ágar. HPLC mostrou a gama de compostos fenólicos (ácido gálico, ácido cafeico, ácido benzoico, ácido cinâmico) e flavonoides. As estruturas químicas de flavonoides e fenólicos encontradas no extrato metanólico da casca de P. granatum L. foram relatadas pela primeira vez. O extrato metanólico da casca (50 ul) de P. granatum L. amarelo apresentou zonas de inibição (ZOI) de 26, 10, 10 e 9mm contra S. aureus, S. Typhimurium, S. Dysenteriae e E. coli, respectivamente. O extrato metanólico de P. granatum L. vermelho (100 ul) apresentou 27, 8, 12 e 15 mm IOI contra Staph. aureus, S. Typhimurium, S. Dysenteriae e E. coli, respectivamente. O ZOI mais alto foi observado contra Staph. aureus. Muitas das bactérias estudadas no presente trabalho podem causar infecções gastrointestinais graves, que podem levar à diarreia hemorrágica em crianças. Essas infecções podem ser fatais para crianças pequenas e idosos. Há um incentivo para encontrar medidas de controle alternativas, como extratos de plantas e ervas, especialmente em países menos desenvolvidos, onde os antibióticos tradicionais podem não estar prontamente disponíveis.

Acid resistance of Salmonella Typhimurium ATCC 14028 after desiccation stress during peanut storage / Avaliação da resistência ácida de Salmonella Typhimurium ATCC 14028 após o estresse dessecativo durante o armazenamento de amendoim

ABSTRACT: Salmonella is a relevant pathogen, which causes foodborne outbreaks associated with both high and low moisture foods (LMF). This study evaluated the effect of previous desiccation stress on the acid resistance of S. Typhimurium ATCC 14028 using blanched peanut kernels as an LMF model. Salmonella was recovered from the peanut samples throughout 180 days of blanched peanut kernels storage at 28 ºC. During this period two death rates were verified, 0.04 log cfu/g/day in the first 30 days and 0.007 log cfu/g/day between 30 and180 days.Regarding acid resistance, there was no difference (P > 0.05) in the Salmonella growth/death kinetics between the undesiccated sample (TSB)and the cells recovered from peanut samples over 180 days of storage after 4 h at pHs 3.0, 3.5, 4.5 and 7.2. The average growth rate observed for pH 7.2 was 0.44 log cfu/ml/h. At pH 4.5, the Salmonella counts did not change significantly over 4 h. In contrast, Salmonella populations declined by 0.14 to 0.29 log cfu/ml/h at pH 3.5. At pH 3.0 declines were estimated to be 0.65 log cfu/ml/h for the undesiccated sample and 2.07 log cfu/ml/h for Salmonella recovered from peanuts stored for 120 days. Therefore, our data indicated that desiccation stress caused during the peanut storagedid not influence the Salmonella acid resistance.

RESUMO: Em alimentos de baixa umidade (LMF), o primeiro desafio encontrado por patógenos como a Salmonella é o estresse de dessecação. Neste estudo, o efeito prévio do estresse de dessecação sobre a resistência ácida de S. Typhimurium ATCC 14028 foi avaliado utilizando amendoim blancheado como um modelo de LMF. Salmonella foi recuperada das amostras de amendoim após 180 dias de estocagem a 28 ºC. Durante este período foram verificadas duas taxas de mortalidade, 0,04 log ufc/g/dia nos primeiros 30 dias e 0,007 log ufc/g/dia entre 30 e 180 dias. Com relação à resistência ácida, não houve diferença (P > 0,05) na cinética de crescimento/morte de Salmonella entre a amostra sem estresse dessecativo (TSB) e as amostras de amendoim após 4 h em pHs 3,0, 3,5, 4,5 e 7,2. A taxa média de crescimento observada para o pH 7,2 foi de 0,44 log cfu/ml/h. No pH 4,5, a contagem de Salmonella não mudou significativamente durante 4 h. Em contraste, a população de Salmonella diminuiu de 0,14 a 0,29 log cfu/ml/h no pH 3,5. No pH 3,0, a queda foi estimada em 0,65 log cfu/ml/h para a amostra sem estresse dessecativo e 2,07 log cfu/ml/h para a Salmonella recuperada das amostras de amendoim estocadas por 120 dias. Portanto, nossos dados indicaram que o estresse dessecativo causado durante a estocagem do amendoim não influenciou a resistência ácida de Salmonella.

Portrayal of Punica granatum L. peel extract through High Performance Liquid Chromatography and antimicrobial activity evaluation / Retrato do extrato de casca de Punica granatum L. por meio de cromatografia líquida de alto desempenho e avaliação da atividade antimicrobiana

Abstract Increasing trend in antimicrobial resistance and failure of chemically synthesized antibiotics lead to discover alternative methods for the treatment of bacterial infections. Various medicinal plants are in use traditionally and their active compounds can be further applied for treatment of bacterial diseases. This study was designed to determine the antibacterial activity of Punica granatum (P. granatum L.) (pomegranate) peel extract against Enterobacteriaceae [Escherichia coli (E. coli), Salmonella Typhimurium (S. Typhimurium) and Shigella Dysenteriae (S. Dysenteriae)] and gram-positive bacterium [Staphylococcus aureus (Staph aureus)]. Methanolic extract of P. granatum L. peel was prepared by Soxhlet apparatus method. Total flavonoid and phenolic contents from the extract were determined by High Performance Liquid Chromatography (HPLC). The antibacterial activity of P. granatum L. peel extract was evaluated through agar well diffusion method. HPLC showed the range of phenolics (gallic acid, caffeic acid, benzoic acid, cinnamic acid) and flavonoid compounds. The chemical structures of flavonoid and phenolics found in the methanolic extract of P. granatum L. peel have been reported for the first time. The methanolic peel extract (50 ul) of yellow P. granatum L. showed 26, 10, 10 and 9mm zones of inhibition (ZOI) against S. aureus, S. Typhimurium, S. Dysenteriae and E. coli, respectively. The methanolic extract of red P. granatum L. (100 ul) showed 27, 8, 12 and 15 mm ZOI against Staph. aureus, S. Typhimurium, S. Dysenteriae and E. coli, respectively. Highest ZOI was observed against Staph. aureus. Many of the bacteria studied in the present work may cause serious gastrointestinal infections, which can lead to hemorrhagic diarrhea in children. These infections can be life-threatening to young children and the elderly. There is an incentive to find alternative control measures, such as plant and herbal extracts, especially in lesser-developed countries where traditional antibiotics may not be readily available.

Resumo A tendência crescente na resistência antimicrobiana e na falha dos antibióticos sintetizados quimicamente leva à descoberta de métodos alternativos para o tratamento de infecções bacterianas. Várias plantas medicinais estão em uso tradicionalmente e seus compostos ativos podem ser posteriormente aplicados para o tratamento de doenças bacterianas. Este estudo foi desenhado para determinar a atividade antibacteriana do extrato de casca de Punica granatum (P. granatum L.) (romã) contra Enterobacteriaceae [Escherichia coli (E. coli), Salmonella Typhimurium (S. Typhimurium) e Shigella Dysenteriae (S. Dysenteriae) ] e bactéria gram-positiva [Staphylococcus aureus (Staph aureus)]. O extrato metanólico da casca de P. granatum L. foi preparado pelo método do aparelho de Soxhlet. O conteúdo total de flavonoides e fenólicos do extrato foi determinado por cromatografia líquida de alta eficiência (HPLC). A atividade antibacteriana do extrato da casca de P. granatum L. foi avaliada através do método de difusão em ágar. HPLC mostrou a gama de compostos fenólicos (ácido gálico, ácido cafeico, ácido benzoico, ácido cinâmico) e flavonoides. As estruturas químicas de flavonoides e fenólicos encontradas no extrato metanólico da casca de P. granatum L. foram relatadas pela primeira vez. O extrato metanólico da casca (50 ul) de P. granatum L. amarelo apresentou zonas de inibição (ZOI) de 26, 10, 10 e 9mm contra S. aureus, S. Typhimurium, S. Dysenteriae e E. coli, respectivamente. O extrato metanólico de P. granatum L. vermelho (100 ul) apresentou 27, 8, 12 e 15 mm IOI contra Staph. aureus, S. Typhimurium, S. Dysenteriae e E. coli, respectivamente. O ZOI mais alto foi observado contra Staph. aureus. Muitas das bactérias estudadas no presente trabalho podem causar infecções gastrointestinais graves, que podem levar à diarreia hemorrágica em crianças. Essas infecções podem ser fatais para crianças pequenas e idosos. Há um incentivo para encontrar medidas de controle alternativas, como extratos de plantas e ervas, especialmente em países menos desenvolvidos, onde os antibióticos tradicionais podem não estar prontamente disponíveis.

Portrayal of Punica granatum L peel extract through High Performance Liquid Chromatography and antimicrobial activity evaluation / Retrato do extrato de casca de Punica granatum L por meio de cromatografia líquida de alto desempenho e avaliação da atividade antimicrobiana

ncreasing trend in antimicrobial resistance and failure of chemically synthesized antibiotics lead to discover alternative methods for the treatment of bacterial infections. Various medicinal plants are in use traditionally and their active compounds can be further applied for treatment of bacterial diseases. This study was designed to determine the antibacterial activity of Punica granatum (P. granatum L.) (pomegranate) peel extract against Enterobacteriaceae [Escherichia coli (E. coli), Salmonella Typhimurium (S. Typhimurium) and Shigella Dysenteriae (S. Dysenteriae)] and gram-positive bacterium [Staphylococcus aureus (Staph aureus)]. Methanolic extract of P. granatum L. peel was prepared by Soxhlet apparatus method. Total flavonoid and phenolic contents from the extract were determined by High Performance Liquid Chromatography (HPLC). The antibacterial activity of P. granatum L. peel extract was evaluated through agar well diffusion method. HPLC showed the range of phenolics (gallic acid, caffeic acid, benzoic acid, cinnamic acid) and flavonoid compounds. The chemical structures of flavonoid and phenolics found in the methanolic extract of P. granatum L. peel have been reported for the first time. The methanolic peel extract (50 ul) of yellow P. granatum L. showed 26, 10, 10 and 9mm zones of inhibition (ZOI) against S. aureus, S. Typhimurium, S. Dysenteriae and E. coli, respectively. The methanolic extract of red P. granatum L. (100 ul) showed 27, 8, 12 and 15 mm ZOI against Staph. aureus, S. Typhimurium, S. Dysenteriae and E. coli, respectively. Highest ZOI was observed against Staph. aureus. Many of the bacteria studied in the present work may cause serious gastrointestinal infections, which can lead to hemorrhagic diarrhea in children. These [...].

A tendência crescente na resistência antimicrobiana e na falha dos antibióticos sintetizados quimicamente leva à descoberta de métodos alternativos para o tratamento de infecções bacterianas. Várias plantas medicinais estão em uso tradicionalmente e seus compostos ativos podem ser posteriormente aplicados para o tratamento de doenças bacterianas. Este estudo foi desenhado para determinar a atividade antibacteriana do extrato de casca de Punica granatum (P. granatum L.) (romã) contra Enterobacteriaceae [Escherichia coli (E. coli), Salmonella Typhimurium (S. Typhimurium) e Shigella Dysenteriae (S. Dysenteriae) ] e bactéria gram-positiva [Staphylococcus aureus (Staph aureus)]. O extrato metanólico da casca de P. granatum L. foi preparado pelo método do aparelho de Soxhlet. O conteúdo total de flavonoides e fenólicos do extrato foi determinado por cromatografia líquida de alta eficiência (HPLC). A atividade antibacteriana do extrato da casca de P. granatum L. foi avaliada através do método de difusão em ágar. HPLC mostrou a gama de compostos fenólicos (ácido gálico, ácido cafeico, ácido benzoico, ácido cinâmico) e flavonoides. As estruturas químicas de flavonoides e fenólicos encontradas no extrato metanólico da casca de P. granatum L. foram relatadas pela primeira vez. O extrato metanólico da casca (50 ul) de P. granatum L. amarelo apresentou zonas de inibição (ZOI) de 26, 10, 10 e 9mm contra S. aureus, S. Typhimurium, S. Dysenteriae e E. coli, respectivamente. O extrato metanólico de P. granatum L. vermelho (100 ul) apresentou 27, 8, 12 e 15 mm IOI contra Staph. aureus, S. Typhimurium, S. Dysenteriae e E. coli, respectivamente. O ZOI mais alto foi observado contra Staph. aureus. Muitas das bactérias estudadas no presente trabalho podem causar infecções gastrointestinais graves, que podem levar à diarreia [...].

Portrayal of Punica granatum L peel extract through High Performance Liquid Chromatography and antimicrobial activity evaluation / Retrato do extrato de casca de Punica granatum L por meio de cromatografia líquida de alto desempenho e avaliação da atividade antimicrobiana

ncreasing trend in antimicrobial resistance and failure of chemically synthesized antibiotics lead to discover alternative methods for the treatment of bacterial infections. Various medicinal plants are in use traditionally and their active compounds can be further applied for treatment of bacterial diseases. This study was designed to determine the antibacterial activity of Punica granatum (P. granatum L.) (pomegranate) peel extract against Enterobacteriaceae [Escherichia coli (E. coli), Salmonella Typhimurium (S. Typhimurium) and Shigella Dysenteriae (S. Dysenteriae)] and gram-positive bacterium [Staphylococcus aureus (Staph aureus)]. Methanolic extract of P. granatum L. peel was prepared by Soxhlet apparatus method. Total flavonoid and phenolic contents from the extract were determined by High Performance Liquid Chromatography (HPLC). The antibacterial activity of P. granatum L. peel extract was evaluated through agar well diffusion method. HPLC showed the range of phenolics (gallic acid, caffeic acid, benzoic acid, cinnamic acid) and flavonoid compounds. The chemical structures of flavonoid and phenolics found in the methanolic extract of P. granatum L. peel have been reported for the first time. The methanolic peel extract (50 ul) of yellow P. granatum L. showed 26, 10, 10 and 9mm zones of inhibition (ZOI) against S. aureus, S. Typhimurium, S. Dysenteriae and E. coli, respectively. The methanolic extract of red P. granatum L. (100 ul) showed 27, 8, 12 and 15 mm ZOI against Staph. aureus, S. Typhimurium, S. Dysenteriae and E. coli, respectively. Highest ZOI was observed against Staph. aureus. Many of the bacteria studied in the present work may cause serious gastrointestinal infections, which can lead to hemorrhagic diarrhea in children. These [...].(AU)

A tendência crescente na resistência antimicrobiana e na falha dos antibióticos sintetizados quimicamente leva à descoberta de métodos alternativos para o tratamento de infecções bacterianas. Várias plantas medicinais estão em uso tradicionalmente e seus compostos ativos podem ser posteriormente aplicados para o tratamento de doenças bacterianas. Este estudo foi desenhado para determinar a atividade antibacteriana do extrato de casca de Punica granatum (P. granatum L.) (romã) contra Enterobacteriaceae [Escherichia coli (E. coli), Salmonella Typhimurium (S. Typhimurium) e Shigella Dysenteriae (S. Dysenteriae) ] e bactéria gram-positiva [Staphylococcus aureus (Staph aureus)]. O extrato metanólico da casca de P. granatum L. foi preparado pelo método do aparelho de Soxhlet. O conteúdo total de flavonoides e fenólicos do extrato foi determinado por cromatografia líquida de alta eficiência (HPLC). A atividade antibacteriana do extrato da casca de P. granatum L. foi avaliada através do método de difusão em ágar. HPLC mostrou a gama de compostos fenólicos (ácido gálico, ácido cafeico, ácido benzoico, ácido cinâmico) e flavonoides. As estruturas químicas de flavonoides e fenólicos encontradas no extrato metanólico da casca de P. granatum L. foram relatadas pela primeira vez. O extrato metanólico da casca (50 ul) de P. granatum L. amarelo apresentou zonas de inibição (ZOI) de 26, 10, 10 e 9mm contra S. aureus, S. Typhimurium, S. Dysenteriae e E. coli, respectivamente. O extrato metanólico de P. granatum L. vermelho (100 ul) apresentou 27, 8, 12 e 15 mm IOI contra Staph. aureus, S. Typhimurium, S. Dysenteriae e E. coli, respectivamente. O ZOI mais alto foi observado contra Staph. aureus. Muitas das bactérias estudadas no presente trabalho podem causar infecções gastrointestinais graves, que podem levar à diarreia [...].(AU)

Identification and characterization of pathogenic and multidrug-resistant bacteria in feral pigeons surrounding a veterinary hospital in Minas Gerais, Brazil / Identificação de bactérias patogênicas e multirresistentes a antimicrobianos em pombos urbanos no entorno de um Hospital Veterinário em Belo Horizonte, Minas Gerais, Brasil

Pigeons are known for their capacity to harbor and spread several zoonotic agents. Studies have suggested that pigeons are also relevant disseminators of multidrug-resistant strains. In this study, pigeons surrounding a veterinary hospital were sampled and tested for the presence of pathogenic Escherichia coli, Salmonella spp., Staphylococcus spp., and Clostridioides (Clostridium) difficile. E. coli isolates from 19 (40.4%) pigeons tested positive for the E. coli heat-stable enterotoxin 1 (EAST1)-encoding gene. The intimin-encoding gene (eae) of enteropathogenicE. coli (EPEC) was found in one isolate (2.1%). Salmonella spp. were found in nine (19.1%) pigeons, all from the first capture event (P < 000.1). S. Typhimurium and S. Heidelberg were isolated from six and three pigeons, respectively. Enterobacterial repetitive intergenic consensus (ERIC-PCR) of the Salmonella spp. isolates suggested that eight of the nine strains had a high genetic similarity, supporting the hypothesis of an outbreak of salmonellosis in these pigeons. Twenty (42.5%) staphylococcal isolates were recovered from 18 (38.3%) pigeons. Eight different species were detected, with S. xylosus being the most frequent. Two (4.3%) C. difficile strains were isolated. Three isolates, one each of S. Typhimurium, S. aureus, and C. difficile, were classified as multidrug-resistant strains. The present research suggested that pigeons residing in urban areas can act as reservoirs and disseminators of pathogenic bacteria, including nosocomial pathogens, such as diarrheagenicE. coli and multidrug-resistant Staphylococcus spp., C. difficile, and Salmonella spp.

Pombos urbanos são conhecidos pela sua capacidade de carrear e disseminar diversos agentes zoonóticos. Estudos tem sugerido que pombos são também relevantes na disseminação de estirpes resistentes a múltiplas drogas. No presente estudo, pombos no ambiente de um hospital veterinário foram amostrados em três diferentes períodos e testados para a presença de Escherichia coli patogênica, Salmonella spp., Staphylococcus spp. e Clostridioides (Clostridium) difficile. Isolados de E. coli de 19 pombos (40.4%) foram positivos para o gene codificador da toxina EAST1. O gene codificador de intimina (eae) do patotipo E. coli enteropatogênica foi encontrada em um isolado (2.1%). Salmonella spp. foi encontrada em nove pombos (19.1%), sendo todos isolados do primeiro período de captura (P < 000.1). S. Typhimurium foi isolado de seis animais e S. Heidelberg de três. A tipagem molecular de isolados de Salmonella spp. por ERIC-PCR demonstrou que oito estirpes possuíam alta similaridade genética entre si, sugerindo a ocorrência de um surto de salmonelose nos animais carreadores. Vinte Staphylococcus (42.5%) foram isolados de 18 animais (38.3%). Oito diferentes espécies foram detectadas, sendo S. xylosus a mais frequente. Duas estirpes de C. difficile não-toxigênica (4.3%) foram isoladas. Uma estirpe de S. Typhimurium, uma de S. aureus e um isolado de C. difficile foram classificados como resistentes a múltiplas drogas antimicrobianas. O presente estudo sugere que pombos capturados no ambiente do hospital veterinário podem atuar como reservatórios e disseminadores de bactérias patogênicas e envolvidas em infecção hospitalar, incluindo E. coli diarreiogênica e Staphylococcus sp., C. difficile e Salmonella spp multirresistente.

The Efficiency of Bacteriophages Against Salmonella Typhimurium Infection in Native Noi Broilers

Though recently considered a therapeutic treatment for commercial broilers, little is known about the effects of bacteriophages on native, slow-growing birds. This study evaluated their efficacy against Salmonella enterica subsp. enterica serovar Typhimurium infected Noi chicken, a native Vietnamese broiler breed. In total, 420 birds were used in a completely randomized design consisting of seven treatments and four replicates of 15 birds. The treatments were NC (negative control), PC (positive control, S. Typhimurium challenged); NC+B1 and NC+B2 (negative control plus B1 or B2 bacteriophage, respectively); PC+B1, PC+B2 (positive control plus B1 or B2 bacteriophage, respectively) and PC+B1B2 (positive control plus both B1 and B2 bacteriophages). After four weeks of infection, the mortality rate in the PC group was 51.1% compared with 11.1% in the PC+B1B2 treatment. Bacteriophage administration had resulted in increased weight gain and decreased feed conversion ratio, particularly when both phages were included in the treatment (p<0.001). Moreover, the relative percentage of carcass weight was lowest in the PC treatment (66.9%) (p<0.001), whereas the other treatments registered similar carcass weight values. Regarding the internal organs, liver weight percentage was higher in the non-treated Salmonella group, and enlarged spleens were also noted in infected chickens even when treated with bacteriophages. The correlation between phage administration and blood parameters was unclear. Although the use of two bacteriophages for therapy was determined to be preferable for the majority of the criteria examined, further genetic characterization of the phages will be required before they can be widely used in chicken farms.(AU)

Prevalence and antimicrobial resistance of Salmonella spp isolated from free-ranging wild boars in the state of São Paulo, Brazil / Prevalência e resistência antimicrobiana de Salmonella spp isoladas em javalis de vida livre no estado de São Paulo

European wild boars (Sus scrofa) are considered exotic invasive species worldwide. Invasions of wild boars are a growing public health concern, as wild boars may represent an important reservoir of zoonotic pathogens, including bacteria of the genus Salmonella. The aim of this study was to determine the prevalence and serovars of Salmonella spp. in free-ranging wild boars legally hunted in the state of São Paulo, Brazil, and the susceptibility of those Salmonella spp. to antimicrobials. Fecal samples and mesenteric lymph nodes were acquired from 63 wild boars. The prevalence of Salmonella spp. in free-ranging wild boars was 9.5 % (6/63; confidence interval: 4.4 % - 19.2 %). Six serovars were isolated: S. enterica subsp. enterica ser. 4,5,12:-:1,2, S. enterica ser. Cerro, S. enterica ser. Madelia, S. enterica ser. Typhimurium, S. enterica ser. I (4,5,12:i:-) and S. enterica ser. Muenster. Analysis of antimicrobial resistance of Salmonella spp. showed that the majority of serovars were fully susceptible to the tested antimicrobials. Only S. enterica ser. Typhimurium and S. enterica ser. Muenster showed a resistance pattern to at least one antimicrobial analyzed. To our knowledge, this study is the first report the prevalence and serovars of Salmonella spp. in free-ranging wild boars in the State of São Paulo, Brazil. Results indicate a low prevalence with variability of Salmonella serovars, with some pattern of antimicrobial resistance. This study highlights the potential role of wild boars as carriers of Salmonella and could pose a risk to wild and domestic animals as well as humans.

Os javalis europeus (Sus scrofa) são considerados uma espécie exótica invasora em todo o mundo. As invasões de javalis são uma preocupação crescente de saúde pública, pois os javalis podem representar um importante reservatório de patógenos zoonóticos, incluindo bactérias do gênero Salmonella. O objetivo deste estudo foi determinar a prevalência e os sorovares de Salmonella spp. em javalis de vida livre caçados legalmente no Estado de São Paulo, Brasil, e a suscetibilidade dessa Salmonella spp. aos antimicrobianos. Amostras fecais e linfonodos mesentéricos foram adquiridos de 63 javalis. A prevalência de Salmonella spp. em javalis selvagens foi de 9,5% (6/63; intervalo de confiança: 4,4% - 19,2%). Seis sorovares foram isolados: S. enterica subsp. enterica ser. 4,5,12:-:1,2, S. enterica ser. Cerro, S. enterica ser. Madelia, S. enterica ser. Typhimurium, S. enterica ser. I (4,5,12:i:-) e S. enterica ser. Muenster. As análises de resistência antimicrobiana de Salmonella spp. evidenciaram que a maioria dos sorovares era pansensível aos antimicrobianos testados. Apenas S. enterica ser. Typhimurium e S. enterica ser. Muenster mostraram um padrão de resistência a pelo menos um antimicrobiano analisado. A saber, este estudo é o primeiro relato da prevalência e de sorovares de Salmonella spp. em javalis de vida livre no Estado de São Paulo, Brasil. Os resultados indicaram baixa prevalência com variabilidade de sorovares de Salmonella, com algum padrão de resistência antimicrobiana. Este estudo destaca o papel potencial dos javalis como portadores de Salmonella spp. e pode representar um risco para os animais domésticos e selvagens, bem como para os humanos.

Phytochemical prospection and evaluation of antimicrobial, antioxidant and antibiofilm activities of extracts and essential oil from leaves of Myrsine umbellata Mart. (Primulaceae) / Prospecção fitoquímica e avaliação da atividade antimicrobiana, antioxidante e antibiofilme de extratos e óleo essencial de folhas de Myrsine umbellata Mart. (Primulaceae)

The species Myrsine umbellata is a native plant of Brazil, whose barks are traditionally used in herbal medicine to treat liver disorders and combat leprosy. Therefore, the aim of the study was to identify the phytochemical prospection of ethanolic (EE) and acetonic (EA) extracts by colorimetric tests and by gas chromatography coupled to mass spectrometry (GC-MS) of the essential oil (EO) of M. umbellata leaves; evaluate the antimicrobial activity in front of standard ATCC strains by the broth microdilution technique; the antioxidant potential by DPPH reduction method and antibiofilm action by crystal violet assay and cell viability was determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) based on optical density. Phytochemical prospection of EE and EA detected the presence of free steroids, alkaloids, flavonoids (flavones, flavononoids, flavonols and xanthons) and tannins in both extracts (EE and EA) and saponins only in EE. In EO, the majority compounds identified were elixene, caryophyllene (E), spatulenol, d-Cadinene and aromadendrene. EA showed antimicrobial activity with MIC and MBC/MFC values ranging from 3.12 to 100 mg.mL-1, highlighting its efficiency on the Gram-positive strain S. epidermidis. EE showed antimicrobial potential in the range of 3.12 to 200 mg.mL-1, and the Gram-negative E. coli strain was the most susceptible. However, OE showed bacteriostatic potential against S. Typhimurium, S. Abaetetuba, P. aeruginosa, and S. epidermidis strains. The ability to sequester free radicals was evident in EA extract with antioxidant activity of 89.55% and in EE with 63.05%. The antibiofilm potential was observed in EE extract which eradicated the mature biofilm biomass of all tested bacteria with high activity (50% to 84.28%) and EO also showed antibiofilm effect on mature biofilm of UEL enteroaggregative E. coli, S. aureus and S. Enteritidis strains with biomass reduction percentage of 63.74%, 68.04% and 86.19%, respectively. These results indicate the potential of M. umbellata extracts and as a source of plant bioactivity for the development of new alternative strategies for the control of planktonic or biofilm-resistant microorganisms.

A espécie Myrsine umbellata é uma planta nativa do Brasil, tradicionalmente suas cascas são empregadas em fitoterapia no tratamento de afecções do fígado e combate a hanseníase. Portanto, o objetivo do estudo foi realizar a prospecção fitoquímica dos extratos etanólico (EE) e acetônico (EA) por meio de testes colorimétricos e por cromatografia gasosa acoplada à espectrometria de massas (CG-EM) do óleo essencial (OE) das folhas de M. umbellata; avaliar a atividade antimicrobiana frente a dozes cepas padrões ATCCs pela técnica de microdiluição em caldo; o potencial antioxidante pelo método de redução de DPPH e ação antibiofilme pela técnica do cristal violeta e a viabilidade celular foi determinada usando 3- (4,5-dimetiltiazol-2-il)-2,5-difeniltetrazólio (MTT) com base na densidade óptica. A prospecção fitoquímica dos EE e EA detectou a presença de esteroides livres, alcaloides, flavonoides (flavonas, flavononóis, flavonóis e xantonas) e taninos em ambos os extratos (EE e EA) e de saponinas somente no EE. No OE os compostos majoritários identificados foram elixeno, cariofileno (E), espatulenol, d-cadineno e aromadendreno. O EA apresentou atividade antimicrobiana com valores de CIM e CBM/CFM que variaram de 3,12 a 100 mg.mL-1, destacando sua eficiência sobre a cepa Gram-positiva S. epidermidis. Já EE apresentou potencial antimicrobiano na faixa que variou de 3,12 a 200 mg.mL-1, e a cepa Gram-negativa E. coli foi a mais suscetível. Entretanto, OE apresentou potencial bacteriostático frente às cepas S. Typhimurium, S. Abaetetuba, P. aeruginosa e S. epidermidis. A capacidade de sequestrar radicais livres foi evidenciada no extrato EA com atividade antioxidante de 89,55% e no EE com 63,05%. O potencial antibiofime foi observado no extrato EE que erradicou a biomassa do biofilme maduro de todas as bactérias testadas com elevada atividade (50% a 84,28%) e OE também apresentou efeito antibiofilme sobre o biofilme maduro das cepas E. coli enteroagreativa UEL, S. aureus e S. Enteritidis com percentual de redução de biomassa de 63,74%, 68,04% e 86,19%, respectivamente. Esses resultados indicam o potencial dos extratos e do OE de M. umbellata como fonte de bioativos vegetais para o desenvolvimento de novas estratégias alternativas para o controle de microrganismos resistentes de forma planctônica ou de biofilmes.

Probiotic Lactobacilli Improved Growth Performance and Attenuated Salmonella Typhimurium Infection Via Jak/Stat Signaling in Broilers

This study aimed to investigate the effect of Lactobacillus plantarum DPP8 and Lactobacillus acidophilus C7282 in feed supplementation on growth performance, Salmonella invasion, inflammation, and mediating signaling in broilers infected with Salmonella Typhimurium (S. Typhimurium). A total of 240 broilers at day old were randomly allocated into four groups, orally infected with S. Typhimurium and supplemented with individual or combined Lactobacilli DPP8 and C7282 at doses of 0 (control), 1010 (individual), or 2.0 × 1010 (combination) cfu/kg of diet for 21 d. The results showed that supplementing Lactobacilli improved (p 0.05) feed intake and body weight gain and decreased (p 0.05) S. Typhimurium load in the caecum, harder gland, spleen and bursa of Fabricius. Also, the supplements decreased (p 0.05) interleukin (1/2/4), tumor necrosis factor and interferon in the serum, enhanced (p 0.05) interleukin 10, and downregulated gene expressions of inflammatory mediators including Janus kinase (Jak2/3), signal transducer and activator of transcription protein (STAT3/4/5/6) in the intestinal mucosa. In contrast, diets containing DPP8 exhibited greater effects on the inhibition of the pathogen and inflammatory response than C7282. The obtained data suggest that Lactobacilli C7282 and DPP8 can be used as feed additives to inhibit colonization and translocation of S. Typhimurium and inflammatory responses via downregulating Jak/STAT signaling in broilers.(AU)

Probiotic Lactobacilli Improved Growth Performance and Attenuated Salmonella Typhimurium Infection Via Jak/Stat Signaling in Broilers

This study aimed to investigate the effect of Lactobacillus plantarum DPP8 and Lactobacillus acidophilus C7282 in feed supplementation on growth performance, Salmonella invasion, inflammation, and mediating signaling in broilers infected with Salmonella Typhimurium (S. Typhimurium). A total of 240 broilers at day old were randomly allocated into four groups, orally infected with S. Typhimurium and supplemented with individual or combined Lactobacilli DPP8 and C7282 at doses of 0 (control), 1010 (individual), or 2.0 × 1010 (combination) cfu/kg of diet for 21 d. The results showed that supplementing Lactobacilli improved (p 0.05) feed intake and body weight gain and decreased (p 0.05) S. Typhimurium load in the caecum, harder gland, spleen and bursa of Fabricius. Also, the supplements decreased (p 0.05) interleukin (1/2/4), tumor necrosis factor and interferon in the serum, enhanced (p 0.05) interleukin 10, and downregulated gene expressions of inflammatory mediators including Janus kinase (Jak2/3), signal transducer and activator of transcription protein (STAT3/4/5/6) in the intestinal mucosa. In contrast, diets containing DPP8 exhibited greater effects on the inhibition of the pathogen and inflammatory response than C7282. The obtained data suggest that Lactobacilli C7282 and DPP8 can be used as feed additives to inhibit colonization and translocation of S. Typhimurium and inflammatory responses via downregulating Jak/STAT signaling in broilers.

Action of benzalkonium chloride in different pH

ABSTRACT Ammonium quaternary compounds are widely used in poultry and swine production as disinfectants in the control of pathogens. They act on gram-positive bacteria, gram-negative bacteria, enveloped fungi and viruses. However, in some conditions of pH and presence of organic matter can be inactivated. This study evaluated the action of ammonium quaternary compounds at 1:1,000 and 1:2,000 dilutions against Salmonella enterica serovarTyphimurium and Salmonella enterica serovar Enteritidis in the presence of three different organic matter simulators, fetal bovine serum, skim milk and whole milk concentration of 1, 3, 5, and 7% and at pH 6 and 9, with 15 min of contact. It was possible to verify that the organic matter simulators adjusted in the same conditions of contact time and percentage, in the in vitro tests, presented different results and the fetal bovine serum did not inactivate the disinfectant. However, the best result against S. Typhimurium and S. Enteritidis was obtained at pH 6 at the dilution of 1:1,000 in all organic matter simulators.

Antimicrobial activity and chemical characterization of Laurel essential oil / Atividade antimicrobiana e caracterização química do óleo essencial de Louro / Actividad antimicrobiana y caracterización química del aceite esencial de Laurel

The factors that arouse interest in the study of essential oils as biocidal agents are numerous, such as the fact that they have antibacterial, antifungal, insecticidal, antioxidant, anti-inflammatory and larvicidal properties. The objective of this work was to evaluate the antimicrobial activity, in vitro, of the laurel (Laurus nobilis L) essential oil on the growth of pathogenic bacteria Salmonella enterica serovar Typhimurium ATCC 14028 and Staphylococcus aureus ATCC 25923, at different exposure times, as well as to perform the chemical characterization. Twenty compounds were identified and quantified, representing 96.57% of the total composition. The class of oxygenated monoterpenes represented the majority class of the essential oil, with 1,8-cineol (33.8%) as the substance found in greater quantity, followed by linalool (17.79%). The third constituent in greater quantity was sabinene (12.23%), belonging to the group of monoterpene hydrocarbons. Terpinyl acetate (9.41%) was also considered to be quantitatively representative. Laurel essential oil showed bacteriostatic activity against S. Typhimurium ATCC 14028 and S. aureus ATCC 25923.(AU)

Os fatores que despertam interesse no estudo dos óleos essenciais como agentes biocidas são inúmeros, como o fato de possuírem propriedades antibacteriana, antifúngica, inseticida, antioxidante, antiinflamatória e larvicida. O objetivo deste trabalho foi avaliar a atividade antimicrobiana, in vitro, do óleo essencial de louro (Laurus nobilis L) sobre o crescimento das bactérias patogênicas Salmonella enterica sorovar Typhimurium ATCC 14028 e Staphylococcus aureus ATCC 25923, em diferentes tempos de exposição, assim como realizar a caracterização química do óleo. Vinte compostos foram identificados e quantificados, representando 96,57% da composição total. A classe dos monoterpenos oxigenados representou a classe majoritária do óleo essencial, sendo o 1,8-cineol (33,8%) a substância encontrada em maior quantidade, seguido do linalol (17,79%). O terceiro constituinte em maior quantidade foi o sabineno (12,23%), pertencente ao grupo dos hidrocarbonetos monoterpênicos. O acetato de terpinila (9,41%) também foi considerado quantitativamente representativo. O óleo essencial de louro apresentou atividade bacteriostática contra S. Typhimurium ATCC 14028 e S. aureus ATCC 25923.(AU)

Los factores que despiertan interés en el estudio de los aceites esenciales como agentes biocidas son innumerables, como el hecho de que tienen propiedades antibacterianas, anti fúngicas, insecticidas, antioxidantes, antiinflamatorias y larvicidas. El objetivo de este trabajo ha sido evaluar la actividad antimicrobiana, in vitro, del aceite esencial de laurel (Laurus nobilis L) sobre el crecimiento de bacterias patógenas Salmonella enterica serovar Typhimurium ATCC 14028 y Staphylococcus aureus ATCC 25923, en diferentes momentos de exposición, así como realizar la caracterización química del aceite. Se identificaron y cuantificaron veinte compuestos, que representan el 96,57% de la composición total. La clase de mono terpenos oxigenados representó la clase principal de aceite esencial, siendo el 1,8-cineol (33,8%) la sustancia que se encuentra en mayor cantidad, seguida del linalol (17,79%). El tercer constituyente en mayor cantidad fue el sabineno (12,23%), perteneciente al grupo de los hidrocarburos monoterpénicos. El acetato de terpinilo (9,41%) también se consideró cuantitativamente representativo. El aceite esencial de laurel mostró actividad bacteriostática contra S. Typhimurium ATCC 14028 y S. aureus ATCC 25923.(AU)

Validation of Alternative Methods of Detection of Salmonella Spp. in Experimentally Contaminated Poultry Environmental Samples

The analysis of Salmonella in the feces and the birds environment is a way of monitoring the colonization in the flocks and verifying the need for the introduction of stricter controls, in such a way that the results of the tests should be known before being sent for slaughter. The polymerase chain reaction (PCR), as well as other rapid methods represent alternatives increasingly used to detect enteric pathogens, but they need proof of effectiveness for their wide use. The aim of this study was to evaluate the equivalence between the results obtained by the methods: real-time PCR (BAX® System), Modified Rappaport-Vassiliadis Semi-solid Medium (MSRV) (ISO 6579) and the traditional method of official reference in Brazil for research of S. Typhimurium and S. Enteritidis in poultry samples. Two hundred and fifty-two samples of disposable shoe covers (DSC) and 252 samples of feces were infected with an average of 2 to 3 log CFU/g of each serovar, and the same samples without fortification were evaluated by the three methods. Five hundred and four diagnoses were obtained with satisfactory results in terms of repeatability (greater than 80%), reproducibility (mean 83,1%), sensitivity (81% to 100%), specificity (95% to 100%), and accuracy (90% to 100%). The compliance test verified that there was not a significant difference between the alternative and the official methods, allowing us to state that the methodologies have had equivalent performances.(AU)

Validation of Alternative Methods of Detection of Salmonella Spp. in Experimentally Contaminated Poultry Environmental Samples

The analysis of Salmonella in the feces and the birds environment is a way of monitoring the colonization in the flocks and verifying the need for the introduction of stricter controls, in such a way that the results of the tests should be known before being sent for slaughter. The polymerase chain reaction (PCR), as well as other rapid methods represent alternatives increasingly used to detect enteric pathogens, but they need proof of effectiveness for their wide use. The aim of this study was to evaluate the equivalence between the results obtained by the methods: real-time PCR (BAX® System), Modified Rappaport-Vassiliadis Semi-solid Medium (MSRV) (ISO 6579) and the traditional method of official reference in Brazil for research of S. Typhimurium and S. Enteritidis in poultry samples. Two hundred and fifty-two samples of disposable shoe covers (DSC) and 252 samples of feces were infected with an average of 2 to 3 log CFU/g of each serovar, and the same samples without fortification were evaluated by the three methods. Five hundred and four diagnoses were obtained with satisfactory results in terms of repeatability (greater than 80%), reproducibility (mean 83,1%), sensitivity (81% to 100%), specificity (95% to 100%), and accuracy (90% to 100%). The compliance test verified that there was not a significant difference between the alternative and the official methods, allowing us to state that the methodologies have had equivalent performances.

Isolation and identification of Salmonella spp. in raw milk from dairy herds in Colombia / Isolamento e identificação de Salmonella spp. no leite cru de rebanhos leiteiros na Colômbia

Salmonellosis is a foodborne disease (FBD) that affects public health and can cause death in people. Many outbreaks of Salmonellosis have been reported due to the contamination of raw milk and dairy products with the pathogen. To determine the prevalence of Salmonella spp. in milk samples from four dairy herds in the Sabana of Bogotá in 2017, 112 milk samples were taken directly from the mammary gland during milking. All milk samples were cultured and tested to isolate and identify Salmonella spp. using microbiological and molecular methods. Salmonella spp. prevalence of milk samples was found to be 20.5% (n=23). The main Salmonella serovars isolated were S. Newport (60.87%), S.Typhimurium (17.4%), S. Virchow, S. Bredeney, and S. Anatum (4.3% each one of the serovars). However, it was not possible to determine the Salmonella serotype in two isolates. The prevalence of Salmonella spp. in milk has not been studied extensively in Colombia. The 20.5% in the prevalence might be due to fact that the sample was taken directly from the mammary gland allowing a better chance of isolation by avoiding the dilutional effect of mixed milk from different cows in the buckets. This also suggests that the infection of the udder could have occurred by hematogenous dissemination or by milking machine contamination. This study highlights the need to implement measures to prevent contamination and reduce the problem in the herds, which will result in milk and dairy products with high standards of innocuity and quality and decrease the risk of foodborne illness(AU)

A salmonelose é uma doença transmitida por alimentos que afeta a saúde pública e pode causar a morte de pessoas. Muitos surtos de salmonelose têm sido relatados devido à contaminação de leite cru e produtos lácteos com o patógeno. Para determinar a prevalência de Salmonella spp. em amostras de leite de quatro rebanhos leiteiros na Sabana de Bogotá em 2017, cento e doze amostras de leite foram colhidas diretamente da glândula mamária durante a ordenha. Todas as amostras de leite foram cultivadas para isolar e identificar Salmonella spp. usando métodos microbiológicos e moleculares. A prevalência de Salmonella spp. nas amostras de leite foi de 20,5% (n = 23). Os principais sorovares de Salmonellaidentificados foram S. Newport (60,87%), S. Typhimurium (17,4%), S. Virchow, S. Bredeney e S. Anatum (4,3% cada um dos sorovares). No entanto, não foram determinados os sorovares de dois isolados. A prevalência de Salmonella spp. no leite ainda não foi extensivamente estudada na Colômbia. Os 20,5% na prevalência podem ser devidos ao fato de a amostra ter sido colhida diretamente da glândula mamária, permitindo uma melhor chance de isolamento, evitando o efeito de diluição do leite misto de diferentes vacas nos baldes, o que pode indicar infecção do úbere pela disseminação hematogênica ou por contaminação da ordenhadeira. Este estudo destaca a necessidade da implementação de medidas destinadas a prevenir a contaminação e reduzir o problema nos rebanhos, resultando em leite e produtos lácteos com altos padrões de inocuidade e qualidade, diminuindo o risco de doenças de origem alimentar.(AU)

Isolation and identification of Salmonella spp. in raw milk from dairy herds in Colombia / Isolamento e identificação de Salmonella spp. no leite cru de rebanhos leiteiros na Colômbia

Salmonellosis is a foodborne disease (FBD) that affects public health and can cause death in people. Many outbreaks of Salmonellosis have been reported due to the contamination of raw milk and dairy products with the pathogen. To determine the prevalence of Salmonella spp. in milk samples from four dairy herds in the Sabana of Bogotá in 2017, 112 milk samples were taken directly from the mammary gland during milking. All milk samples were cultured and tested to isolate and identify Salmonella spp. using microbiological and molecular methods. Salmonella spp. prevalence of milk samples was found to be 20.5% (n=23). The main Salmonella serovars isolated were S. Newport (60.87%), S.Typhimurium (17.4%), S. Virchow, S. Bredeney, and S. Anatum (4.3% each one of the serovars). However, it was not possible to determine the Salmonella serotype in two isolates. The prevalence of Salmonella spp. in milk has not been studied extensively in Colombia. The 20.5% in the prevalence might be due to fact that the sample was taken directly from the mammary gland allowing a better chance of isolation by avoiding the dilutional effect of mixed milk from different cows in the buckets. This also suggests that the infection of the udder could have occurred by hematogenous dissemination or by milking machine contamination. This study highlights the need to implement measures to prevent contamination and reduce the problem in the herds, which will result in milk and dairy products with high standards of innocuity and quality and decrease the risk of foodborne illness(AU)

A salmonelose é uma doença transmitida por alimentos que afeta a saúde pública e pode causar a morte de pessoas. Muitos surtos de salmonelose têm sido relatados devido à contaminação de leite cru e produtos lácteos com o patógeno. Para determinar a prevalência de Salmonella spp. em amostras de leite de quatro rebanhos leiteiros na Sabana de Bogotá em 2017, cento e doze amostras de leite foram colhidas diretamente da glândula mamária durante a ordenha. Todas as amostras de leite foram cultivadas para isolar e identificar Salmonella spp. usando métodos microbiológicos e moleculares. A prevalência de Salmonella spp. nas amostras de leite foi de 20,5% (n = 23). Os principais sorovares de Salmonellaidentificados foram S. Newport (60,87%), S. Typhimurium (17,4%), S. Virchow, S. Bredeney e S. Anatum (4,3% cada um dos sorovares). No entanto, não foram determinados os sorovares de dois isolados. A prevalência de Salmonella spp. no leite ainda não foi extensivamente estudada na Colômbia. Os 20,5% na prevalência podem ser devidos ao fato de a amostra ter sido colhida diretamente da glândula mamária, permitindo uma melhor chance de isolamento, evitando o efeito de diluição do leite misto de diferentes vacas nos baldes, o que pode indicar infecção do úbere pela disseminação hematogênica ou por contaminação da ordenhadeira. Este estudo destaca a necessidade da implementação de medidas destinadas a prevenir a contaminação e reduzir o problema nos rebanhos, resultando em leite e produtos lácteos com altos padrões de inocuidade e qualidade, diminuindo o risco de doenças de origem alimentar.(AU)

Action of benzalkonium chloride in different pH

Ammonium quaternary compounds are widely used in poultry and swine production as disinfectants in the control of pathogens. They act on gram-positive bacteria, gram-negative bacteria, enveloped fungi and viruses. However, in some conditions of pH and presence of organic matter can be inactivated. This study evaluated the action of ammonium quaternary compounds at 1:1,000 and 1:2,000 dilutions against Salmonella enterica serovarTyphimurium and Salmonella enterica serovar Enteritidis in the presence of three different organic matter simulators, fetal bovine serum, skim milk and whole milk concentration of 1, 3, 5, and 7% and at pH 6 and 9, with 15 min of contact. It was possible to verify that the organic matter simulators adjusted in the same conditions of contact time and percentage, in the in vitro tests, presented different results and the fetal bovine serum did not inactivate the disinfectant. However, the best result against S. Typhimurium and S. Enteritidis was obtained at pH 6 at the dilution of 1:1,000 in all organic matter simulators.

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)