Deletions of ttrA and pduA genes in Salmonella enterica affect survival within chicken-derived HD-11 macrophages.

In mammals, enteric salmonellas can use tetrathionate (ttr), formed as a by-product from the inflammatory process in the intestine, as electron acceptor in anaerobic respiration, and it can fuel its energy metabolism by degrading the microbial fermentation product 1,2-propanediol. However, recent studies have shown that this mechanism is not important for Salmonella infection in the intestine of poultry, while it prolongs the persistence of Salmonella at systemic sites in this species. In the current study, we show that ΔttrApduA strains of Salmonella enterica have lower net survival within chicken-derived HD-11 macrophages, as CFU was only 2.3% (S. Enteritidis ΔttrApduA), 2.3% (S. Heidelberg ΔttrApduA), and 3.0% (S. Typhimurium ΔttrApduA) compared to wild-type strains after 24 h inside HD-11 macrophage cells. The difference was not related to increased lysis of macrophages, and deletion of ttrA and pduA did not impair the ability of the strains to grow anaerobically. Further studies are indicated to determine the reason why Salmonella ΔttrApduA strains survive less well inside macrophage cell lines.

Occurrence of Salmonella spp. in the broiler production chain / [Ocorrência de Salmonella spp. na cadeia de produção de carne de frango]

ABSTRACT Brazilian chicken meat is exported to more than 150 countries and consumed by consumer markets that demand high quality and food safety, thus, requiring very strict control of pathogens present in food to guarantee these rigorous safety standards. This study evaluates the reports from the Salmonella spp. Control and Monitoring Program of the Brazilian Ministry of Agriculture, Livestock and Food Supply of seven slaughterhouses inspected by the Federal Inspection Service from the western region of Paraná state, Brazil, from March 2017 to February 2019. The broiler litter swab and carcass analyses revealed a Salmonella spp. positivity ratio of 5.9% (19/319) and 23.5% (75/319), respectively. The concomitant presence of Salmonella spp. in the broiler litter swab and chicken carcasses occurred in 58% of the positive samples. The most frequently isolated serovar in the carcasses was Salmonella Heidelberg (85.3%) followed by Salmonella spp. (10.6%). During slaughter, carcass positivity to Salmonella spp. was significantly different (p=0.047) between the first (19.6%) and the second (29.4%) shifts. The results alert for the possibility of carcass contamination during slaughtering and, therefore, more stringent hygiene measures between shifts must be implemented to mitigate carcass contamination.

RESUMO A carne de frango brasileira é consumida em mais de 150 países, em mercados exigentes com a qualidade e a produção de alimentos seguros, o que justifica o controle de patógenos nesse alimento, a fim de assegurar tais requisitos. O presente estudo analisou dados constantes dos relatórios do Programa de Controle e Monitoramento da Salmonella spp. do Ministério da Agricultura, Pecuária e Abastecimento do Brasil (MAPA), realizado em sete unidades avícolas e frigoríficas da região oeste do estado do Paraná, com Serviço de Inspeção Federal, no período entre março 2017 e fevereiro de 2019. A análise dos dados revelou a presença de Salmonella spp. no suabe de cama de frango em 5,9% dos lotes analisados e em 23,5% das carcaças oriundas desses lotes. A presença concomitante de Salmonella spp. no suabe de cama e nas carcaças de frango do lote ocorreu em 58% das amostras positivas. O sorovar mais frequentemente isolado nas carcaças foi Salmonella Heidelberg (85,3%), seguido de Salmonella spp. (10,6%). Durante o abate, observou-se diferença significativa (P=0,047) na positividade das carcaças para Salmonella spp. entre o primeiro (19,6%) e o segundo turno (29,4%). Os resultados indicam a possibilidade de contaminação das carcaças durante o abate, portanto a adoção de medidas mais rigorosas de higienização entre os turnos deve ser implementada a fim de mitigar a contaminação das carcaças.

Genomic analyses of drug-resistant Salmonella enterica serovar Heidelberg strains isolated from meat and related sources between 2013 and 2017 in the south region of Brazil.

Salmonella enterica serovar Heidelberg (S. Heidelberg) is a zoonotic, ubiquitous, and worldwide-distributed pathogen, responsible for gastroenteritis in humans caused by the consumption of contaminated food. In this study, 11 S. Heidelberg strains isolated from chicken and bovine meat, drag swab, and animal feed between 2013 and 2017 in states of the southern region of Brazil were characterized by whole-genome sequencing (WGS) analyses. Antimicrobial resistance against 18 antimicrobials was determined by disk-diffusion and ciprofloxacin's minimum inhibitory concentration by Etest®. The search for resistance and virulence genes, plasmids, Salmonella Pathogenicity Islands (SPIs) plus multi-locus sequence typing (MLST), and single-nucleotide polymorphisms (SNPs) analyses was conducted using WGS data. All strains harbored resistance genes fosA7, aac(6')-Iaa, sul2, tet(A), blaCMY-2, mdsA, and mdsB, and point mutations in gyrA and parC. All strains showed a phenotypic multidrug-resistant profile, with resistant or intermediate resistant profiles against 14 antimicrobials tested. Plasmids ColpVC, IncC, IncX1, and IncI1-I(Alpha) were detected. Virulence genes related to adherence, macrophage induction, magnesium uptake, regulation, and type III secretion systems plus 10 SPIs were detected. All strains were assigned to ST15 and belonged to two SNP clusters showing high similarity to isolates from the United Kingdom, Chile, Germany, the Netherlands, China, South Africa, and South Korea. In conclusion, the presence of multidrug-resistant S. Heidelberg strains in Brazil showing a global genomic relationship may alert for the necessity of stronger surveillance measures by food safety and public health authorities to limit its spread to humans and animals through foods.

High Genetic Similarity Among Salmonella Heidelberg Isolated from Poultry Farms, Wild Animals, Beef, Poultry and Pork Meat, and Humans in Brazil

Salmonellosis is an important gastrointestinal infection in humans and cause of foodborne outbreaks in the world. In this context, molecular characterization is essential to understand how the strains circulate. The aim of this study was to evaluate the genotypic distribution of S. Heidelberg according to the source of isolation. The genetic relatedness of the S. Heidelberg isolates was determined by pulsed-field gel electrophoresis (PFGE). The most prevalent pulsotypes of cluster A were BRJF6X01.006 (27/95 = 28,42%) related between 1995 and 2011 in broilers, poultry meat and poultry farms, meat product and human, and BRJF6X01.001 (21/95 = 22,10%) related between 2011 and 2017 in wild animals, broilers, poultry meat, poultry farms, meat product, animal feed, and pork meat. The pulsotype BRJF6X01.001 shows a high distribution in the environmental and productive chain. The degree of similarity between pulsotypes BRJF6X01.006 and BRJF6X01.001 is 88%. To ensure the safety of human and animal health, holistic approaches, including surveillance of Salmonella throughout the environment and in the production chain, together with control measures, are critical. As transmission of Salmonella from food producing animals to wildlife and to the environment is considered potential public health problem, information on the survival and persistence of Salmonella in the environment and in potential reservoirs is of considerable importance.(AU)

Overview of antimicrobial resistance and virulence factors in Salmonella spp. isolated in the last two decades from chicken in Brazil.

Foodborne infections caused by Salmonella have been linked to a variety of poultry products. The aim of this study was to compare the molecular profile of virulence genes considering different serotypes of Salmonella, isolates were from chicken breast sampled during the last two decades (1999 to 2010 and 2011 to 2018). The resistance to antimicrobials was also evaluated, establishing a comparative epidemiological parameter on the pathogenic potential on this bacterium over time. We tested 238 Salmonella isolates, and 18 different serotypes were observed. These being S. Enteritidis (42.3%, 58/137) and S. Ohio (28.3%, 36/137), the most frequent in the first decade; and S. Heidelberg (25.7%, 26/101) and S. Typhimurium (21.8%, 22/101), in the second. We found four (1.68%) multidrug resistant isolates from the first decade and 28 (11.76%) in the second. All extended spectrum beta-lactamase (ESBL) positive isolates belonged to the S. Heidelberg serotype, and were also detected in the second decade. Considering the nine different antimicrobial classes tested, an increase in the number of resistant isolates was observed over time: from five classes with resistant isolates in the first decade to eight classes in the second, with cefotaxime being the antimicrobial with the highest number of resistant isolates in both decades. All isolates (100%) presented the invA, sitC and tolC genes. In sequence, the most frequent genes were flgL (99.6%), sopB (98.3%), flgK (97.9%), fljB (96.6%), sipA (94.9%), sipB (88.6%), sifA (86.4%), sipD (66.1%), ssaR (51.3%), sopD (37.3%) and spvB (34.3%) was the least frequent; and 13 isolates showing all 14 virulence genes investigated. The ability of these isolates to resist certain antimicrobials, and to express genes encoding virulence factors, reinforce their marked pathogenic potential; while the possibility to trigger diseases in humans through the food chain is a serious public health threat through.

Emergence, Dissemination and Antimicrobial Resistance of the Main Poultry-Associated Salmonella Serovars in Brazil.

Salmonella infects poultry, and it is also a human foodborne pathogen. This bacterial genus is classified into several serovars/lineages, some of them showing high antimicrobial resistance (AMR). The ease of Salmonella transmission in farms, slaughterhouses, and eggs industries has made controlling it a real challenge in the poultry-production chains. This review describes the emergence, dissemination, and AMR of the main Salmonella serovars and lineages detected in Brazilian poultry. It is reported that few serovars emerged and have been more widely disseminated in breeders, broilers, and layers in the last 70 years. Salmonella Gallinarum was the first to spread on the farms, remaining as a concerning poultry pathogen. Salmonella Typhimurium and Enteritidis were also largely detected in poultry and foods (eggs, chicken, turkey), being associated with several human foodborne outbreaks. Salmonella Heidelberg and Minnesota have been more widely spread in recent years, resulting in frequent chicken/turkey meat contamination. A few more serovars (Infantis, Newport, Hadar, Senftenberg, Schwarzengrund, and Mbandaka, among others) were also detected, but less frequently and usually in specific poultry-production regions. AMR has been identified in most isolates, highlighting multi-drug resistance in specific poultry lineages from the serovars Typhimurium, Heidelberg, and Minnesota. Epidemiological studies are necessary to trace and control this pathogen in Brazilian commercial poultry production chains.

Clustered Regularly Interspaced Short Palindromic Repeats Genotyping of Multidrug-Resistant Salmonella Heidelberg Strains Isolated From the Poultry Production Chain Across Brazil.

Salmonella enterica subsp. enterica serovar Heidelberg has been associated with a broad host range, such as poultry, dairy calves, swine, wild birds, environment, and humans. The continuous evolution of S. Heidelberg raises a public health concern since there is a global dispersal of lineages harboring a wide resistome and virulome on a global scale. Here, we characterized the resistome, phylogenetic structure and clustered regularly interspaced short palindromic repeats (CRISPR) array composition of 81 S. Heidelberg strains isolated from broiler farms (n = 16), transport and lairage (n = 5), slaughterhouse (n = 22), and retail market (n = 38) of the poultry production chain in Brazil, between 2015 and 2016 using high-resolution approaches including whole-genome sequencing (WGS) and WGS-derived CRISPR genotyping. More than 91% of the S. Heidelberg strains were multidrug-resistant. The total antimicrobial resistance (AMR) gene abundances did not vary significantly across regions and sources suggesting the widespread distribution of antibiotic-resistant strains from farm to market. The highest AMR gene abundance was observed for fosA7, aac(6')-Iaa, sul2, tet(A), gyrA, and parC for 100% of the isolates, followed by 88.8% for bla CMY-2. The ß-lactam resistance was essentially driven by the presence of the plasmid-mediated AmpC (pAmpC) bla CMY-2 gene, given the isolates which did not carry this gene were susceptible to cefoxitin (FOX). Most S. Heidelberg strains were classified within international lineages, which were phylogenetically nested with Salmonella strains from European countries; while CRISPR genotyping analysis revealed that the spacer content was overall highly conserved, but distributed into 13 distinct groups. In summary, our findings underscore the potential role of S. Heidelberg as a key pathogen disseminated from farm to fork in Brazil and reinforce the importance of CRISPR-based genotyping for salmonellae. Hence, we emphasized the need for continuous mitigation programs to monitor the dissemination of this high-priority pathogen.

Nanocomposite of Ag-Doped ZnO and Ag2O nanocrystals in control of Salmonella Heidelberg biofilms formed in commercial egg / Nanocompostos de Ag-Doped ZnO e nanocristais de Ag2O no controle da formação de biofilmes de Salmonella Heidelberg em ovos comerciais

Salmonella spp. is an important causal agent of salmonellosis in humans. Controlling Salmonella spp. in eggs is important as the bacterium passes through the shell to an embryo and remains in the terrain. Disinfection is usually performed by using several sanitizers. However, novel, more efficient ways of controlling this agent have been studied with advances in nanotechnology, including nanoparticles. Preliminary studies of nanoparticles have shown they are successful in controlling such microorganisms. Standardizing the ideal concentration of this nanocomposite is fundamental for optimum efficiency in the control of Salmonella spp. In this study, eggs from commercial laying chickens were purchased from local trade and treated in laboratory with silver and zinc nanoparticles in different concentrations. Biofilm was formed 24 hours after that; then, the eggs were washed for the removal of free bacteria. Conventional microbiology was performed to isolate Salmonella spp., and PCR was performed to identify colonies. The effectiveness of using nanocomposite of silver oxide with silver-doped zinc oxide (ZnO:Ag-AgO) was evaluated in different concentrations to prevent the formation of eggshell biofilms.(AU)

As Salmonellas spp. são importantes agentes causadores de salmonelose em humanos. O controle da Salmonella spp. é importante, pois a bactéria ultrapassa a barreira da casca atingindo o embrião e infecta lotes de aves que podem levar a infecção ao ser humano. A desinfecção costuma ser feita por vários sanitizantes; porém, com os avanços da nanotecnologia, formas novas e mais eficientes de controle desse agente estão sendo estudadas, como as nanopartículas. Estudos preliminares dessas nanopartículas têm mostrado o sucesso de seu uso no controle de microrganismos. A padronização da concentração ideal de uso desse nanocomposto é fundamental para a máxima eficiência no controle de Salmonella spp. Ovos vermelhos oriundos de postura comercial foram comprados no comércio local e tratados em laboratório com as nanopartículas em diferentes concentrações; após 24 horas, formaram o biolfilme. Os ovos foram lavados para a retirada das bactérias livres. Realizaram-se exame microbiológico convencional, para isolamento de Salmonella spp., e PCR, para identificação das colônias. O objetivo deste artigo foi avaliar a eficácia da utilização de nanocompostos de óxido de prata com óxido de zinco dopado com óxido de prata (ZnO: Ag-Ago) em diferentes concentrações na prevenção da formação de biofilmes na casca dos ovos.(AU)

Nanocomposite of Ag-Doped ZnO and Ag2O nanocrystals in control of Salmonella Heidelberg biofilms formed in commercial egg / Nanocompostos de Ag-Doped ZnO e nanocristais de Ag2O no controle da formação de biofilmes de Salmonella Heidelberg em ovos comerciais

Salmonella spp. is an important causal agent of salmonellosis in humans. Controlling Salmonella spp. in eggs is important as the bacterium passes through the shell to an embryo and remains in the terrain. Disinfection is usually performed by using several sanitizers. However, novel, more efficient ways of controlling this agent have been studied with advances in nanotechnology, including nanoparticles. Preliminary studies of nanoparticles have shown they are successful in controlling such microorganisms. Standardizing the ideal concentration of this nanocomposite is fundamental for optimum efficiency in the control of Salmonella spp. In this study, eggs from commercial laying chickens were purchased from local trade and treated in laboratory with silver and zinc nanoparticles in different concentrations. Biofilm was formed 24 hours after that; then, the eggs were washed for the removal of free bacteria. Conventional microbiology was performed to isolate Salmonella spp., and PCR was performed to identify colonies. The effectiveness of using nanocomposite of silver oxide with silver-doped zinc oxide (ZnO:Ag-AgO) was evaluated in different concentrations to prevent the formation of eggshell biofilms.

As Salmonellas spp. são importantes agentes causadores de salmonelose em humanos. O controle da Salmonella spp. é importante, pois a bactéria ultrapassa a barreira da casca atingindo o embrião e infecta lotes de aves que podem levar a infecção ao ser humano. A desinfecção costuma ser feita por vários sanitizantes; porém, com os avanços da nanotecnologia, formas novas e mais eficientes de controle desse agente estão sendo estudadas, como as nanopartículas. Estudos preliminares dessas nanopartículas têm mostrado o sucesso de seu uso no controle de microrganismos. A padronização da concentração ideal de uso desse nanocomposto é fundamental para a máxima eficiência no controle de Salmonella spp. Ovos vermelhos oriundos de postura comercial foram comprados no comércio local e tratados em laboratório com as nanopartículas em diferentes concentrações; após 24 horas, formaram o biolfilme. Os ovos foram lavados para a retirada das bactérias livres. Realizaram-se exame microbiológico convencional, para isolamento de Salmonella spp., e PCR, para identificação das colônias. O objetivo deste artigo foi avaliar a eficácia da utilização de nanocompostos de óxido de prata com óxido de zinco dopado com óxido de prata (ZnO: Ag-Ago) em diferentes concentrações na prevenção da formação de biofilmes na casca dos ovos.

Recent Evolution and Genomic Profile of Salmonella enterica Serovar Heidelberg Isolates from Poultry Flocks in Brazil.

Salmonella enterica serovar Heidelberg is isolated from poultry-producing regions around the world. In Brazil, S. Heidelberg has been frequently detected in poultry flocks, slaughterhouses, and chicken meat. The goal of the present study was to assess the population structure, recent temporal evolution, and some important genetic characteristics of S. Heidelberg isolated from Brazilian poultry farms. Phylogenetic analysis of 68 S. Heidelberg genomes sequenced here and additional whole-genome data from NCBI demonstrated that all isolates from the Brazilian poultry production chain clustered into a monophyletic group, here called S. Heidelberg Brazilian poultry lineage (SH-BPL). Bayesian analysis defined the time of the most recent common ancestor (tMRCA) as 2004, and the overall population size (Ne) was constant until 2008, when an ∼10-fold Ne increase was observed until circa 2013. SH-BPL presented at least two plasmids with replicons ColpVC (n = 68; 100%), IncX1 (n = 66; 97%), IncA/C2 (n = 65; 95.5%), ColRNAI (n = 43; 63.2%), IncI1 (n = 32; 47%), ColMG828, Col156, IncHI2A, IncHI2, IncQ1, IncX4, IncY, and TrfA (each with n < 4; <4% each). Antibiotic resistance genes were found, with high frequencies of fosA7 (n = 68; 100%), mdf(A) (n = 68; 100%), tet(34) (n = 68; 100%), sul2 (n = 64; 94.1%), and blaCMY-2 (n = 56; 82.3%), along with an overall multidrug resistance (MDR) profile. Ten Salmonella pathogenicity islands (SPI1 to SPI5, SPI9, and SPI11 to SPI14) and 139 virulence genes were also detected. The SH-BPL profile was like those of other previous S. Heidelberg isolates from poultry around the world in the 1990s. In conclusion, the present study demonstrates the recent introduction (2004) and high level of dissemination of an MDR S. Heidelberg lineage in Brazilian poultry operations. IMPORTANCES. Heidelberg is the most frequent serovar in several broiler farms from the main Brazilian poultry-producing regions. Therefore, avian-source foods (mainly chicken carcasses) commercialized in the country and exported to other continents are contaminated with this foodborne pathogen, generating several national and international economic losses. In addition, isolates of this serovar are usually resistant to antibiotics and can cause human invasive and septicemic infection, representing a public health concern. This study demonstrates the use of whole-genome sequencing (WGS) to obtain epidemiological information for one S. Heidelberg lineage highly spread among Brazilian poultry farms. This information will help to define biosecurity measures to control this important Salmonella serovar in Brazilian and worldwide poultry operations.

Virulence genes identification and characterization revealed the presence of the Yersinia High Pathogenicity Island (HPI) in Salmonella from Brazil.

Salmonella spp. is one of the major agents of foodborne disease worldwide, and its virulence genes are responsible for the main pathogenic mechanisms of this micro-organism. The whole-genome sequencing (WGS) of pathogens has become a lower-cost and more accessible genotyping tool providing many gene analysis possibilities. This study provided an in silico investigation of 129 virulence genes, including plasmidial and bacteriophage genes from Brazilian strains' public Salmonella genomes. The frequency analysis of the four most sequenced serovars and a temporal analysis over the past four decades was also performed. The NCBI sequence reads archive (SRA) database comprised 1077 Salmonella public whole-genome sequences of strains isolated in Brazil between 1968 and 2018. Among the 1077 genomes, 775 passed in Salmonella in silico Typing (SISTR) quality control, which also identified 41 different serovars in which the four most prevalent were S. Enteritidis, S. Typhimurium, S. Dublin, and S. Heidelberg. Among these, S. Heidelberg presented the most distinct virulence profile, besides presenting Yersinia High Pathogenicity Island (HPI), rare and first reported in Salmonella from Brazil. The genes mgtC, csgC, ssaI and ssaS were the most prevalent within the 775 genomes with more than 99% prevalence. On the other hand, the less frequent genes were astA, iucBCD, tptC and shdA, with less than 1% frequency. All of the plasmids and bacteriophages virulence genes presented a decreasing trend between the 2000 s and 2010 s decades, except for the phage gene grvA, which increased in this period. This study provides insights into Salmonella virulence genes distribution in Brazil using freely available bioinformatics tools. This approach could guide in vivo and in vitro studies besides being an interesting method for the investigation and surveillance of Salmonella virulence. Moreover, here we propose the genes mgtC, csgC, ssaI and ssaS as additional targets for PCR identification of Salmonella in Brazil due to their very high frequency in the studied genomes.

Molecular characterization and antimicrobial resistance profiles of Salmonella Heidelberg isolates from poultry.

In the last 10 years, Salmonella Heidelberg has been extensively isolated from poultry in several countries. In this context, molecular characterization is essential to understand whether the strains have entered the farms from a single or several sources. Thus, the aim of this study was to determine the genetic relationship and antimicrobial susceptibility of S. Heidelberg strains isolated between 2011 and 2012 from broiler farms belonging to three integrated poultry companies located in Argentina. The genetic relatedness of the S. Heidelberg isolates was determined by pulsed-field gel electrophoresis (PFGE), and resistance to 21 antimicrobials was determined by the disc diffusion method. The isolates were assigned to four PFGE patterns. Most of the strains showed 100% similarity and belonged to the same integrated poultry company. This PFGE pattern was also prevalent in S. Heidelberg strains isolated from humans in several provinces of Argentina, which suggests an epidemiological association between human and poultry strains. All the isolates were classified as multidrug-resistant (MDR), and no clear relationship was observed between PFGE and resistance patterns. S. Heidelberg strains may circulate among farms from the same integrated company due to common sources of contamination. To guarantee the safety of the poultry product for the consumers, holistic approaches including surveillance of Salmonella throughout the production chain together with control measures are crucial.

Antimicrobial and disinfectant resistance of Salmonella Heidelberg from Brazilian flocks did not increase for ten years (2006-2016)

ABSTRACT: Salmonella is a major cause of foodborne illness worldwide, and poultry and its derived products are the most common food products associated with salmonellosis outbreaks. Some countries, including Brazil, have experienced an increased prevalence of Salmonella Heidelberg among their poultry flocks. Some isolates have also presented high resistance to antimicrobial agents and persist in the poultry farm environment. This study aimed to compare the susceptibility of S. Heidelberg strains isolated in 2006 with those isolated in 2016 against disinfectants and antimicrobial agents. The results showed that all the strains were highly susceptible to sodium hypochlorite, regardless of the conditions and year of isolation. Resistance to benzalkonium chloride varied according to the conditions applied, but not to the year of isolation. Increased antimicrobial resistance from 2006-2016 was observed only for tetracycline. The results suggest that the antimicrobial and disinfectant resistance of S. Heidelberg did not increase for ten years (2006-2016). However, further analysis should include a larger number of S. Heidelberg isolates from poultry origin and additional antimicrobial agents for more precise conclusions about the increasing in antimicrobial resistance in the last years.

RESUMO: Salmonella é uma das principais causas das doenças transmitidas por alimento em todo o mundo, e a carne de frango e produtos derivados são os principais alimentos associados com surtos de salmonelose em humanos. Alguns países, incluindo o Brasil, têm observado um aumento da ocorrência de Salmonella Heidelberg nas suas granjas avícolas. Além disto, alguns isolados têm apresentado alta resistência aos antimicrobianos e têm persistido no ambiente de produção avícola. Neste contexto, o objetivo deste estudo foi comparar a susceptibilidade de cepas de S. Heidelberg isoladas em 2006 com aquelas isoladas em 2016 contra desinfetantes e agentes antimicrobianos. Os resultados demonstraram que as cepas foram altamente resistentes a hipoclorito de sódio, independentemente das condições e do ano de isolamento. A resistência ao cloreto de benzalcônio variou de acordo com as condições testadas, mas não com o ano de isolamento. Um aumento da resistência aos antimicrobianos de 2006 a 2016 foi observado apenas para tetraciclina. Os resultados sugerem que a resistência aos desinfetantes e aos antimicrobianos não aumentou em um período de dez anos (2006-2016). Entretanto, novas análises devem incluir um número maior de cepas de S. Heidelberg isoladas de fontes avícolas e outros agentes antimicrobianos para uma conclusão mais precisa sobre o aumento da resistência antimicrobiana nos últimos anos.

Antimicrobial and disinfectant resistance of Salmonella Heidelberg from Brazilian flocks did not increase for ten years (2006-2016) / A resistência a desinfetantes e a antimicrobianos não aumentou em um período de 10 anos (2006 a 2016) em Salmonella Heidelberg isoladas de granjas avícolas brasileiras

Salmonella is a major cause of foodborne illness worldwide, and poultry and its derived products are the most common food products associated with salmonellosis outbreaks. Some countries, including Brazil, have experienced an increased prevalence of Salmonella Heidelberg among their poultry flocks. Some isolates have also presented high resistance to antimicrobial agents and persist in the poultry farm environment. This study aimed to compare the susceptibility of S. Heidelberg strains isolated in 2006 with those isolated in 2016 against disinfectants and antimicrobial agents. The results showed that all the strains were highly susceptible to sodium hypochlorite, regardless of the conditions and year of isolation. Resistance to benzalkonium chloride varied according to the conditions applied, but not to the year of isolation. Increased antimicrobial resistance from 2006-2016 was observed only for tetracycline. The results suggest that the antimicrobial and disinfectant resistance of S. Heidelberg did not increase for ten years (2006-2016). However, further analysis should include a larger number of S. Heidelberg isolates from poultry origin and additional antimicrobial agents for more precise conclusions about the increasing in antimicrobial resistance in the last years.(AU)

Salmonella é uma das principais causas das doenças transmitidas por alimento em todo o mundo, e a carne de frango e produtos derivados são os principais alimentos associados com surtos de salmonelose em humanos. Alguns países, incluindo o Brasil, têm observado um aumento da ocorrência de Salmonella Heidelberg nas suas granjas avícolas. Além disto, alguns isolados têm apresentado alta resistência aos antimicrobianos e têm persistido no ambiente de produção avícola. Neste contexto, o objetivo deste estudo foi comparar a susceptibilidade de cepas de S. Heidelberg isoladas em 2006 com aquelas isoladas em 2016 contra desinfetantes e agentes antimicrobianos. Os resultados demonstraram que as cepas foram altamente resistentes a hipoclorito de sódio, independentemente das condições e do ano de isolamento. A resistência ao cloreto de benzalcônio variou de acordo com as condições testadas, mas não com o ano de isolamento. Um aumento da resistência aos antimicrobianos de 2006 a 2016 foi observado apenas para tetraciclina. Os resultados sugerem que a resistência aos desinfetantes e aos antimicrobianos não aumentou em um período de dez anos (2006-2016). Entretanto, novas análises devem incluir um número maior de cepas de S. Heidelberg isoladas de fontes avícolas e outros agentes antimicrobianos para uma conclusão mais precisa sobre o aumento da resistência antimicrobiana nos últimos anos.(AU)

Antimicrobial and disinfectant resistance of Salmonella Heidelberg from Brazilian flocks did not increase for ten years (2006-2016) / A resistência a desinfetantes e a antimicrobianos não aumentou em um período de 10 anos (2006 a 2016) em Salmonella Heidelberg isoladas de granjas avícolas brasileiras

Salmonella is a major cause of foodborne illness worldwide, and poultry and its derived products are the most common food products associated with salmonellosis outbreaks. Some countries, including Brazil, have experienced an increased prevalence of Salmonella Heidelberg among their poultry flocks. Some isolates have also presented high resistance to antimicrobial agents and persist in the poultry farm environment. This study aimed to compare the susceptibility of S. Heidelberg strains isolated in 2006 with those isolated in 2016 against disinfectants and antimicrobial agents. The results showed that all the strains were highly susceptible to sodium hypochlorite, regardless of the conditions and year of isolation. Resistance to benzalkonium chloride varied according to the conditions applied, but not to the year of isolation. Increased antimicrobial resistance from 2006-2016 was observed only for tetracycline. The results suggest that the antimicrobial and disinfectant resistance of S. Heidelberg did not increase for ten years (2006-2016). However, further analysis should include a larger number of S. Heidelberg isolates from poultry origin and additional antimicrobial agents for more precise conclusions about the increasing in antimicrobial resistance in the last years.(AU)

Salmonella é uma das principais causas das doenças transmitidas por alimento em todo o mundo, e a carne de frango e produtos derivados são os principais alimentos associados com surtos de salmonelose em humanos. Alguns países, incluindo o Brasil, têm observado um aumento da ocorrência de Salmonella Heidelberg nas suas granjas avícolas. Além disto, alguns isolados têm apresentado alta resistência aos antimicrobianos e têm persistido no ambiente de produção avícola. Neste contexto, o objetivo deste estudo foi comparar a susceptibilidade de cepas de S. Heidelberg isoladas em 2006 com aquelas isoladas em 2016 contra desinfetantes e agentes antimicrobianos. Os resultados demonstraram que as cepas foram altamente resistentes a hipoclorito de sódio, independentemente das condições e do ano de isolamento. A resistência ao cloreto de benzalcônio variou de acordo com as condições testadas, mas não com o ano de isolamento. Um aumento da resistência aos antimicrobianos de 2006 a 2016 foi observado apenas para tetraciclina. Os resultados sugerem que a resistência aos desinfetantes e aos antimicrobianos não aumentou em um período de dez anos (2006-2016). Entretanto, novas análises devem incluir um número maior de cepas de S. Heidelberg isoladas de fontes avícolas e outros agentes antimicrobianos para uma conclusão mais precisa sobre o aumento da resistência antimicrobiana nos últimos anos.(AU)

Electrochemically-Activated Water Presents Bactericidal Effect Against Salmonella Heidelberg Isolated from Poultry Origin.

Salmonella spp. are among the most important pathogens in poultry farming, and Salmonella Heidelberg (SH) is one of the most frequent serotypes isolated in Brazil. SH has a zoonotic potential and stands out as a pathogen that is difficult to eliminate from the poultry chain due to its resistance to disinfectants. One alternative to traditional disinfectants is the electrochemically-activated water (ECA), a bactericidal compound produced from the electrolysis of salt and water. ECA generators produce a compound that consists of free chlorine, hypochlorous acid, and other free radicals. This alternative control method is safe for human health and reduces environmental contamination. The present study aimed at evaluating the efficacy of ECA against 30 SH isolates from poultry origin in scenarios that simulated the chiller environment (4°C, 5 and 50 parts per million [ppm], 5 and 40 min of exposure) and the cleaning and disinfection process (25°C, 200 ppm, 5 and 10 min of exposure). In the quantitative test, SH was susceptible to ECA. The mean bacterial counts decreased significantly compared to the control group, especially at 200 ppm. At this concentration, ECA inhibited the growth of almost 87% of the Salmonella strains, and the results showed a significant decrease in the mean bacterial counts for both exposure times (5 and 10 min). These findings demonstrate that ECA is effective against SH in vitro and it is a possible alternative to disinfection in the poultry industry for the control of this pathogen. However, in situ tests in the food industry are needed.

Influence of the norepinephrine and medium acidification in the growth and adhesion of Salmonella Heidelberg isolated from poultry.

Salmonella spp. are among the leading pathogens responsible for foodborne illnesses worldwide. Bacterial communities use a quorum sensing (QS) system to control biofilm formation. QS is a cell-to-cell signaling mechanism involving compounds called auto-inducers (AI). Norepinephrine utilizes the same bacterial signaling of AI-3 and serves as a signal of QS. Acid stress is a challenge encountered by microorganisms in food processing environments and in the gastrointestinal tracts of hosts. Thus, adaptation to acidic environments may increase the pathogenicity of the strain. The aim of this study was to evaluate the influence of two concentrations of norepinephrine (100 µM and 250 µM) and acidification (pH 3.0) of the medium on the growth and adhesion of Salmonella Heidelberg strains isolated from poultry sources at 12 °C and 25 °C. Furthermore, three genes associated with the biofilm formation process were detected (adrA, csgD, and sidA). Norepinephrine stimulation did not influence the growth or adhesion of Salmonella Heidelberg strains, regardless of the catecholamine concentration and temperature. On the other hand, the use of acidified medium (pH 3.0) resulted in a significant reduction of growth and a significant increase of S. Heidelberg adhesion at both temperatures, indicating that the acidified medium favors the biofilm formation process. The adrA and sidA genes showed higher detection frequencies than csgD. Experiments analyzing the biofilm production process by S. Heidelberg strains are not common, and further studies are necessary to understand this complex process.

High Prevalence of Multidrug-Resistant Nontyphoidal Salmonella Recovered from Broiler Chickens and Chicken Carcasses in Brazil

The extensive use of antimicrobial agents has contributed to the emergence of antimicrobial resistance and multidrug resistance (MDR) in Salmonella, an important zoonotic pathogen that causes outbreaks and sporadic cases of gastroenteritis in humans. The study aimed to investigate the antimicrobial resistance profile of Salmonella strains isolated from poultry in Brazil. A total of 230 Salmonella strains, isolated from cloacal swabs (n=56) and broiler carcasses swabs (n=174) before and after chilling from slaughterhouses under Federal Inspection Service within the period 2012-2017, were analyzed. Serotyping and antibiotic susceptibility testing were performed on all the isolates. Serotyping results showed that 41% of the strains were Salmonella Heidelberg, 29% S. Minnesota, 12% S. Saintpaul, 6.5% S. Enteritidis, 3.9% S. Anatum, 2.2% S. Cerro, 2.2% S. Senftenberg, 1.7% S. Newport, 0.4% S. Ealing, 0.4% S. O:4,5 and 0.4% S. O:9,12. MDR rates of the isolates were 67.4%. S. Heidelberg 89.5%, S. Minnesota 51.5%, S. Saintpaul 82.1%, S. Anatum 66.7%, S. Cerro 60%, S. Senftenberg 40%. Out of the 230 strains, 41.3% presented resistance to Penicillins + beta-lactamase inhibitor, Penicillin, 1st and 2nd Generation Cephalosporin, 3rd and 4th Generation Cephalosporin, Tetracycline and Sulfonamide. Salmonella Heidelberg, S. Saintpaul, S. Anatum, S. Cerro, S. Senftenberg and S. Minnesota were isolated after chilling tank highlighting a food safety concern for the industry of poultry and poultry products indicating a risk to collective health. The high prevalence of MDR nontyphoidal Salmonella obtained in this study limit the options available to treat infectious disease in humans and animals.(AU)

High Prevalence of Multidrug-Resistant Nontyphoidal Salmonella Recovered from Broiler Chickens and Chicken Carcasses in Brazil

The extensive use of antimicrobial agents has contributed to the emergence of antimicrobial resistance and multidrug resistance (MDR) in Salmonella, an important zoonotic pathogen that causes outbreaks and sporadic cases of gastroenteritis in humans. The study aimed to investigate the antimicrobial resistance profile of Salmonella strains isolated from poultry in Brazil. A total of 230 Salmonella strains, isolated from cloacal swabs (n=56) and broiler carcasses swabs (n=174) before and after chilling from slaughterhouses under Federal Inspection Service within the period 2012-2017, were analyzed. Serotyping and antibiotic susceptibility testing were performed on all the isolates. Serotyping results showed that 41% of the strains were Salmonella Heidelberg, 29% S. Minnesota, 12% S. Saintpaul, 6.5% S. Enteritidis, 3.9% S. Anatum, 2.2% S. Cerro, 2.2% S. Senftenberg, 1.7% S. Newport, 0.4% S. Ealing, 0.4% S. O:4,5 and 0.4% S. O:9,12. MDR rates of the isolates were 67.4%. S. Heidelberg 89.5%, S. Minnesota 51.5%, S. Saintpaul 82.1%, S. Anatum 66.7%, S. Cerro 60%, S. Senftenberg 40%. Out of the 230 strains, 41.3% presented resistance to Penicillins + beta-lactamase inhibitor, Penicillin, 1st and 2nd Generation Cephalosporin, 3rd and 4th Generation Cephalosporin, Tetracycline and Sulfonamide. Salmonella Heidelberg, S. Saintpaul, S. Anatum, S. Cerro, S. Senftenberg and S. Minnesota were isolated after chilling tank highlighting a food safety concern for the industry of poultry and poultry products indicating a risk to collective health. The high prevalence of MDR nontyphoidal Salmonella obtained in this study limit the options available to treat infectious disease in humans and animals.

Changes on Confocal Scanning Laser Ophthalmoscopy with the Heidelberg Retinal Tomography after a Cardiac Catheterism in a Patient with Progressive Glaucoma.

PURPOSE: We present a case of a patient with progressive open angle glaucoma who presented changes suggestive of improvement in the Heidelberg retinal tomography 3 (HRT3) analysis after a cardiac catheterization. OBSERVATION: A 69-year-old woman presented with progressive open angle glaucoma despite maximum tolerable antiglaucomatous topical treatment. A filtering surgery (trabeculectomy) was performed and successfully achieved intraocular pressure (IOP) levels of 10 mm Hg on average. Despite this, changes were evidenced in the HRT3 protocols (trend analysis and topographic change analysis) suggesting marked progression. Brimonidine 0.2% twice a day was initiated, and a cardiovascular examination was requested. A cardiac catheterism was performed in the following weeks, and afterward, all structural parameters improved until the last control. Medication was not discontinued, and no signs of apparent progression on the HRT3 parameters have been evidenced up until the time of writing this case report. CONCLUSIONS AND IMPORTANCE: There was a marked improvement in the HRT3 parameters (trend and topographic change analysis), suggesting that the progression stopped after a cardiac catheterism in a patient with progressive glaucoma despite having the IOP controlled. To our knowledge, this is the first case of a patient with progressive glaucoma that was medically and surgically managed, and despite achieving low IOP levels, the progression detected by the HRT3 analysis could not be stopped until a cardiac catheterization was performed.