Latex proteins downregulate inflammation and restores blood-coagulation homeostasis in acute Salmonella infection

BACKGROUND Calotropis procera latex protein fraction (LP) was previously shown to protect animals from septic shock. Further investigations showed that LP modulate nitric oxide and cytokines levels. OBJECTIVES To evaluate whether the protective effects of LP, against lethal bacterial infection, is observed in its subfractions (LPPII and LPPIII). METHODS Subfractions (5 and 10 mg/kg) were tested by i.p. administration, 24 h before challenging with lethal injection (i.p.) of Salmonella Typhimurium. LPPIII (5 mg/kg) which showed higher survival rate was assayed to evaluate bacterial clearance, histopathology, leukocyte recruitment, plasma coagulation time, cytokines and NO levels. FINDINGS LPPIII protected 70% of animals of death. The animals given LPPIII exhibited reduced bacterial load in blood and peritoneal fluid after 24 h compared to the control. LPPIII promoted macrophage infiltration in spleen and liver. LPPIII restored the coagulation time of infected animals, increased IL-10 and reduced NO in blood. MAIN CONCLUSIONS LPPIII recruited macrophages to the target organs of bacterial infection. This addressed inflammatory stimulus seems to reduce bacterial colonisation in spleen and liver, down regulate bacterial spread and contribute to avoid septic shock.

Salmonelosis invasiva en un hospital de Lima, Perú / Invasive salmonellosis in a hospital in Lima, Peru

RESUMEN El objetivo del estudio fue determinar las características epidemiológicas, clínicas y laboratoriales de los casos de salmonelosis invasiva y el perfil de susceptibilidad antibiótica de aislamientos de salmonela (2013-2017), en una serie de casos de pacientes con Salmonella spp. aislada de secreciones y/o líquidos corporales con o sin coprocultivo positivo (n=70). Para la evaluación de la susceptibilidad antibiótica se consideró el primer aislamiento en todos los casos de salmonelosis (n=168). La mayor frecuencia de casos ocurrió entre 0 a 4 años (14,3%) y mayores de 65 años (24,3%). Los síntomas más frecuentes fueron fiebre (66,1%), diarrea (40,7%) y trastorno del sensorio (40,7%). La infección por el virus de inmunodeficiencia humana (VIH) fue la comorbilidad más frecuente (42,4%). La frecuencia de susceptibilidad fue de 83,3% a ceftriaxona, 78,8% a cotrimoxazol y 75,0% a cloranfenicol. Sólo 50,8% fueron susceptibles a ciprofloxacino. Concluimos que, la salmonelosis invasiva fue más frecuente en niños pequeños y ancianos, y que la comorbilidad más frecuente fue la infección por VIH.

ABSTRACT The study's objective was to determine the epidemiological, clinical, and laboratory characteristics of cases of invasive salmonellosis and the antibiotic susceptibility profile of salmonella isolates (2013-2017), in a series of cases of patients with Salmonella spp. isolated from secretions and/or body fluids with or without positive stool culture (n=70). For the evaluation of antibiotic susceptibility, the first isolate was considered in all cases of salmonellosis (n=168). The highest frequency of cases occurred between 0 to 4 years (14.3%) and over 65 years (24.3%). The most frequent symptoms were fever (66.1%), diarrhea (40.7%), and sensory issues (40.7%). Human immunodeficiency virus (HIV) infection was the most common co-morbidity (42.4%). The frequency of susceptibility was 83.3% to ceftriaxone, 78.8% to cotrimoxazole, and 75.0% to chloramphenicol. Only 50.8% were susceptible to ciprofloxacin. We concluded that invasive salmonellosis was more common in young children and the elderly and that HIV infection was the most common comorbidity.

Review of molecular subtyping methodologies used to investigate outbreaks due to multidrug-resistant enteric bacterial pathogens in sub-Saharan Africa

Background: In sub-Saharan Africa, molecular epidemiological investigation of outbreaks caused by antimicrobial-resistant enteric bacterial pathogens have mostly been described for Salmonella species, Vibrio cholerae, Shigella species and Escherichia coli. For these organisms, I reviewed all publications describing the use of molecular subtyping methodologies to investigate outbreaks caused by multidrug-resistant (MDR) enteric bacterial infections.Objectives: To describe the use of molecular subtyping methodologies to investigate outbreaks caused by MDR enteric bacterial pathogens in sub-Saharan Africa and to describe the current status of molecular subtyping capabilities in the region. Methods: A PubMed database literature search (English language only) was performed using the search strings: 'Africa outbreak MDR', 'Africa outbreak multi', 'Africa outbreak multidrug', 'Africa outbreak multi drug', 'Africa outbreak resistance', 'Africa outbreak resistant', 'Africa outbreak drug', 'Africa outbreak antibiotic', 'Africa outbreak antimicrobial'. These search strings were used in combination with genus and species names of the organisms listed above. All results were included in the review. Results: The year 1991 saw one of the first reports describing the use of molecular subtyping methodologies in sub-Saharan Africa; this included the use of plasmid profiling to characterise Salmonella Enteritidis. To date, several methodologies have been used; pulsed-field gel electrophoresis analysis and multilocus sequence typing have been the most commonly used methodologies. Investigations have particularly highlighted the emergence and spread of MDR clones; these include Salmonella Typhi H58 and Salmonella Typhimurium ST313 clones. In recent times, whole-genome sequencing (WGS) analysis approaches have increasingly been used. Conclusion: Traditional molecular subtyping methodologies are still commonly used and still have their place in investigations; however, WGS approaches have increasingly been used and are slowly gaining a stronghold. African laboratories need to start adapting their molecular surveillance methodologies to include WGS, as it is foreseen that WGS analysis will eventually replace all traditional methodologies

Comparative study of egg contamination with SalmonellaHeidelberg and Salmonella Typhimurium / Estudo comparativo da contaminação de ovos com SalmonellaHeidelberg e Salmonella Typhimurium

Cases of salmonellosis in humans have been associated with consumption of eggs contaminated with this bacterial pathogen due to insufficient heat treatment. The most prevalent serotypes of Salmonella in Brazil include serotypes Enteritidis, Typhimurium, and Heidelberg. The first two serotypes are major causes for eggs to be withheld from sale and for recalls over Salmonella contamination concerns in both domestic and foreign markets. Eggs may be contaminated through transovarian infection (transovarial transmission) due to the presence of the microorganism in the hen's oviduct and bacterial penetration of the eggshell. There is little data in the literature on the susceptibility of egg contamination and eggshell penetration by Brazilian serotypes of Salmonella. The present study aimed to evaluate the ability of S. Heidelberg and S. Typhimurium serotypes to penetrate through the eggshell and detect these bacteria in the albumen and yolk according to the thickness of the eggshell. SPF (specific-pathogen-free) eggs were artificially contaminated by contact with moist cotton containing Salmonella (15 x 108 CFU/ml). Eggs were divided into the following groups: negative control (not contaminated), S. Heidelberg, and S. Typhimurium. Subsequently, these eggs were incubated at 37°C, and their contents analyzed after 4 h and 24 h of incubation. The evaluation (assessment) of the contamination was performed by traditional bacteriology and confirmed by biochemical and serological tests. Treatments were compared with Fisher's test using a SAS statistical software. For S. Heidelberg, the percentage of positivity (positive cases) was lower in both albumen and yolk at 4 h and 24 h intervals (33.33% and 3.7%, and 3.7% and 3.7%, respectively) compared to S. Typhimurium (26.63% and 7.41%, and 33.33% and 33.33%, respectively). These findings suggest that the former strain (S. Heidelberg) was unable to survive in the hostile environment of the albumen. In contrast, eggshell thickness had no significant correlation with the number of positive samples. In conclusion, the results obtained in the egg infection model show that the Salmonella strains tested were able to penetrate the eggshell and multiply in both the albumen and yolk and that S. Typhimurium proved to be the most efficient to grow within these portions of the egg.(AU)

Salmonelose em humanos é frequentemente associada ao consumo de ovos contaminados sem o devido processamento térmico. No Brasil, os sorotipos mais prevalentes são: Enteritidis, Typhimurium e Heidelberg, alvo de barreiras sanitárias na comercialização de ovos. O ovo pode ser contaminado por via transovariana, pela presença da bactéria no oviduto da ave e também por penetração da bactéria através da casca do ovo. Existem poucas informações acerca da capacidade de contaminação no ovo por sorotipos isolados no Brasil. Este estudo teve como objetivo avaliar a capacidade dos sorotipos S. Heidelberg e S. Typhimurium penetrar através da casca do ovo e colonizar a albumina e gema, relacionando à espessura da casca. Os ovos SPF (livres de patógenos específicos) foram contaminados artificialmente pelo contato com algodão umedecido (15 x 108 CF/mL). Os ovos foram divididos nos seguintes grupos: controle negativo (sem contaminação), S. Heidelberg e S. Typhimurium. Posteriormente foram incubadas a 37°C e seu conteúdo foi analisado após 4 e 24 h. A avaliação da contaminação foi realizada por bacteriologia tradicional e confirmada por testes bioquímicos e sorológicos. Os tratamentos foram comparados com o teste de Fisher usando o software estatístico SAS. Para S. Heidelberg, a percentagem de positividade foi menor no albúmen e gema às 4 e 24 h (33,33% e 3,7%, 3,7% e 3,7%, respectivamente) em comparação com S. Typhimurium (26,63% e 7,41%, 33,33% e 33,33%, respectivamente), sugerindo que a primeira estirpe foi mais vulnerável as condições hostis da albumina. Por outro lado, a espessura da casca do ovo não teve relação significativa com a positividade das amostras. Em conclusão, o modelo de infecção do ovo mostrou que as cepas foram capazes de penetrar a casca do ovo e sobreviver na albumina e gema, sendo que o sorotipo S. Typhimurium foi mais eficiente.(AU)

Septic arthritis caused by Salmonella enterica serotype Rubislaw: A case report

Abstract An eleven-year-old boy presented with fever and hip pain, with limited mobility of the right side of the hip. Computed tomography scan revealed an increased volume of the right coxo-femoral joint, requiring surgical drainage of purulent secretion, from which Salmonella enterica was isolated. After four weeks of treatment with third-generation cephalosporin, he was discharged with a favorable evolution. Invasive disease caused by Salmonella spp represents a small proportion of salmonellosis cases, although it is responsible for greater rates of hospitalization, morbidity and mortality. Children under 5 years, elders over 60 years and immunodeficient patients have greater risk for invasive salmonellosis.

Increasing prevalence and dissemination of invasive nontyphoidal Salmonella serotype Typhimurium with multidrug resistance in hospitalized patients from southern Brazil

ABSTRACT Introduction: Nontyphoidal Salmonella serotypes are the main cause of human food-borne infection, including several hospitalization cases in the developing countries. Aim: To detect the main serotypes and to characterize the antibiotic resistance of human non-enteric and enteric nontyphoidal Salmonella from clinical isolates in Brazil. Methods: Salmonella serotypes were identified by microbiological and molecular methods. Susceptibility testing to antibiotics was performed by agar disk diffusion. Real-time PCRs were carried out for the detection of the genus Salmonella as well as serotypes Typhimurium and Enteritidis. Results: A total of 307 nontyphoidal Salmonella were isolated from 289 different patients in a reference laboratory (LACEN-RS) from Southern Brazil in a six-year period (2010-2015). There were 45 isolates from emerging cases and 244 from sporadic cases in hospitalized patients. Non-enteric isolates were detected in 42.6% of the patients from sources such as urine, blood and other clinical fluids. Serological and PCR-specific tests demonstrated that Typhimurium (48.4%) and Enteritidis (18.3%) were the most frequent serotypes. Typhimurium isolates were generally resistant to three or more antibiotic classes, while Enteritidis isolates to one or two classes. Typhimurium was the most frequent serotype in all samples (48.4%), mainly among the hospitalized patients (55.6%), and presented the highest rates of multidrug resistance (59.3% of the isolates of this serotype). Further, the prevalence of this serotype increased along the years of the study in comparison to other nontyphoidal Salmonella serotypes. Conclusion: Greater public health attention should be given to prevent salmonellosis in the community and in hospital settings to reduce the rates of Typhimurium strains with multidrug resistance.

Infecção sistêmica por Salmonella Typhimurium em papagaio-verdadeiro (Amazona aestiva) / Systemic Infection by Salmonella Typhimurium in Blue-fronted Amazon Parrot (Amazona aestiva)

The maintenance of wild animals in captivity can be a source for transmission of infectious and zoonotic diseases. In February 2016, blue-fronted amazon parrots that were kept at the Centro de Reabilitação de Animais Silvestres (CRAS) of Campo Grande - MS died suddenly. The specimens were sent to the Universidade Federal de Mato Grosso do Sul (UFMS), Faculdade de Medicina Veterinária e Zootecnia (FAMEZ) to be necropsied. Anatomopathological exams were performed and organ fragments from all systems were collected for histopathological exams. Liver and spleen fragments were also collected for bacteriological exams. Histopathological exam revealed bacterial aggregates distributed through the organs. Bacteriological exam isolated Salmonella spp. from the fragments of liver and spleen. The confirmation of the genus was made by serum agglutination on slide and by the polymerase chain reaction (PCR). The genetic sequencing identified the sample as Salmonella Typhimurium.(AU)

Un quinquenio de experiencia (2005-2010) con infecciones por Salmonella spp en un centro nacional de referencia en pediatría / A five-year experience with zoonotic Salmonella at a pediatric reference centre

Resumen Introducción: Salmonella sp puede causar infecciones asintomáticas, gastroenteritis, bacteriemia e infecciones focales como meningitis y osteomielitis. Objetivo: Describir aspectos microbiológicos y clínicos de las infecciones por Salmonella spp en niños en un hospital de referencia pediátrico Centro Hospitalario Pereira Rossell. Montevideo Uruguay. Material y Métodos: Estudio descriptivo y retrospectivo de pacientes en quienes se aislara Salmonella spp en el período 1 de enero de 2005 al 31 de diciembre de 2010. Resultados: Se aisló Salmonella spp en 46 niños menores de 15 años. Dieciocho eran menores de 2 años y 5 niños menores de tres meses. 24% de los pacientes presentaba factores de riesgo (infección por VIH; enfermedad hemato-oncológica, desnutrición) y co-morbilidades (bajo peso al nacer y neumonía). No hubo fallecidos. Los serotipos más frecuentes fueron: Typhimurium y Enteritidis. La mayoría de las cepas eran sensibles a ampicilina y cefalosporinas de tercera generación. Discusión: La presentación clínica predominante fue diarrea con sangre, no se presentaron brotes. Basados en los perfiles de susceptibilidad antimicrobiana, se pueden mantener las recomendaciones hasta el momento sugeridas. Conclusiones: Se debe tener en cuenta la infección por Salmonella sp en niños febriles con riesgo de enfermedad bacteriana invasora, con o sin focalidad.

Background: Salmonella can cause asymptomatic infections, diarrhea, bacteremia and focal infections such as meningitis and osteomyelitis. Aim: To describe clinical and microbiological aspects of infections by Salmonella spp. in children in a pediatric referral hospital: Centro Hospitalario Pereira Rossell, in Montevideo, Uruguay. Materials and Methods: Descriptive and retrospective study of 46 patients, from which Salmonella spp was isolated between January 1, 2005 and December 31, 2010. Results: Salmonella spp was isolated in 46 children younger than 15 years old. 18 were below 2 years old and 5 children below three months. 24% of the children had risk factors, such as HIV infection, oncological diseases and malnutrition; low birth weight and pneumonia were associated conditions. No deaths were reported. The serotypes more frequently found were: Typhimurium and Enteritidis. Most of the strains were susceptible to ampicillin and third generation of cephalosporins. Discussion: Diarrhea with blood was the predominant clinical presentation, and there were no outbreaks. Typhimurium and Enteritidis were the most common serotypes. Based on the profiles of susceptibility antimicrobial, we could maintain the same recommendations until the moment suggested. Conclusions: we must consider the Salmonella infection in febrile children under risk of an invasive bacterial disease, with or without focal infection.

Prevalence, serotyping and antimicrobials resistance mechanism of Salmonella enterica isolated from clinical and environmental samples in Saudi Arabia

Abstract Salmonella is recognized as a common foodborne pathogen, causing major health problems in Saudi Arabia. Herein, we report epidemiology, antimicrobial susceptibility and the genetic basis of resistance among S. enterica strains isolated in Saudi Arabia. Isolation of Salmonella spp. from clinical and environmental samples resulted in isolation of 33 strains identified as S. enterica based on their biochemical characteristics and 16S-rDNA sequences. S. enterica serovar Enteritidis showed highest prevalence (39.4%), followed by S. Paratyphi (21.2%), S. Typhimurium (15.2%), S. Typhi and S. Arizona (12.1%), respectively. Most isolates were resistant to 1st and 2nd generation cephalosporin; and aminoglycosides. Moreover, several S. enterica isolates exhibited resistance to the first-line antibiotics used for Salmonellosis treatment including ampicillin, trimethoprim-sulfamethoxazole and chloramphenicol. In addition, the results revealed the emergence of two S. enterica isolates showing resistance to third-generation cephalosporin. Analysis of resistance determinants in S. enterica strains (n = 33) revealed that the resistance to β-lactam antibiotics, trimethoprim-sulfamethoxazole, chloramphenicol, and tetracycline, was attributed to the presence of carb-like, dfrA1, floR, tetA gene, respectively. On the other hand, fluoroquinolone resistance was related to the presence of mutations in gyrA and parC genes. These findings improve the information about foodborne Salmonella in Saudi Arabia, alarming the emergence of multi-drug resistant S. enterica strains, and provide useful data about the resistance mechanisms.

Differential roles for pathogenicity islands SPI-13 and SPI-8 in the interaction of Salmonella Enteritidis and Salmonella Typhi with murine and human macrophages

BACKGROUND: Salmonella pathogenicity island (SPI)-13 is conserved in many serovars of S. enterica, including S. Enteritidis, S. Typhimurium and S. Gallinarum. However, it is absent in typhoid serovars such as S. Typhi and Paratyphi A, which carry SPI-8 at the same genomic location. Because the interaction with macrophages is a critical step in Salmonella pathogenicity, in this study we investigated the role played by SPI-13 and SPI-8 in the interaction of S. Enteritidis and S. Typhi with cultured murine (RAW264.7) and human (THP-1) macrophages. RESULTS: Our results showed that SPI-13 was required for internalization of S. Enteritidis in murine but not human macrophages. On the other hand, SPI-8 was not required for the interaction of S. Typhi with human or murine macrophages. Of note, the presence of an intact copy of SPI-13 in a S. Typhi mutant carrying a deletion of SPI-8 did not improve its ability to be internalized by, or survive in human or murine macrophages. CONCLUSIONS: Altogether, our results point out to different roles for SPI-13 and SPI-8 during Salmonella infection. While SPI-13 contributes to the interaction of S. Enteritidis with murine macrophages, SPI-8 is not required in the interaction of S. Typhi with murine or human macrophages. We hypothesized that typhoid serovars have lost SPI-13 and maintained SPI-8 to improve their fitness during another phase of human infection.

Salmonella enterica: una revisión de la trilogía agente, hospedero y ambiente, y su trascendencia en Chile / Salmonella enterica: a review or the trilogy agent, host and environment and its importance in Chile

Salmonella enterica is a major foodborne pathogen worldwide, being the main cause of outbreaks by food consumption in Chile. Despite all efforts deployed for control and prevention, the high incidence in people still persists, with several factors that could be influencing the epidemiological behavior of this infection. The objective of this review is to identify these factors belonging to the biological agent, the human host and the environment, which probably have a greater importance in Chile. Thus, priority areas for research of S. enterica are inferred, which hopefully will help to understand its spread in nature and its success as a wide host range pathogen. In the future, increased understanding of these determinants will facilitate the implementation of biosecurity and surveillance strategies for the prevention of disease in people and animals.

Salmonella enterica es uno de los principales patógenos transmitidos por los alimentos en el mundo, siendo la primera causa de brotes de intoxicación alimentaria en Chile. A pesar de todos los esfuerzos de control y prevención desplegados, la incidencia en las personas se ha mantenido alta, por lo que diversos factores podrían estar influenciando el comportamiento epidemiológico de esta infección. El objetivo de esta revisión es describir factores referidos tanto al agente biológico, al hospedero humano y al medio ambiente, que podrían tener mayor trascendencia en Chile. De esta forma, se infieren ámbitos prioritarios para la investigación de S. enterica, que permitan entender su dispersión en la naturaleza y su éxito como patógeno de un amplio rango de hospederos. A futuro, el mayor conocimiento de estos determinantes facilitará la implementación de estrategias de bioseguridad y vigilancia para la prevención de la enfermedad en las personas y en los animales.

Characterization of quinolone resistance in Salmonella spp. isolates from food products and human samples in Brazil

Abstract Non-typhoidal salmonellosis is an important zoonotic disease caused by Salmonella enterica. The aim of this study was to investigate the prevalence of plasmid-mediated quinolone resistance in Salmonella spp. and its association with fluoroquinolone susceptibility in Brazil. A total of 129 NTS isolates (samples from human origin, food from animal origin, environmental, and animal) grouped as from animal (n = 62) and human (n = 67) food were evaluated between 2009 and 2013. These isolates were investigated through serotyping, antimicrobial susceptibility testing, and the presence of plasmid-mediated quinolone resistance (PMQR) genes (qnr, aac(6')-Ib) and associated integron genes (integrase, and conserved integron region). Resistance to quinolones and/or fluoroquinolones, from first to third generations, was observed. Fifteen isolates were positive for the presence of qnr genes (8 qnrS, 6 qnrB, and 1 qnrD) and twenty three of aac(6')-Ib. The conserved integron region was detected in 67 isolates as variable regions, from ±600 to >1000 pb. The spread of NTS involving PMQR carriers is of serious concern and should be carefully monitored.

Endocarditis y artritis séptica por Salmonella no Typhi productora de β-lactamasas de espectro extendido: A case report / Endocarditis and arthritis caused by extended spectrum β-lactamase-producing non-Typhi Salmonella

We present the case of a patient with endocarditis and arthritis caused by extended spectrum β-lactamase producing non-Typhi Salmonella, with incomplete response (defined as persistence of Salmonella in joint fluid) to initial instituted treatment (trimethoprim-sulfamethoxazole) and posterior recovery with ertapenem. The disease was associated with implantable central venous catheter infection. Five percent of patients with non-Typhi Salmonella gastroenteritis develop bacteremia. Infective endocarditis and joint infection has been reported in 1,4% and less than 1% of cases, respectively.

Se presenta el caso de un paciente con endocarditis y artritis séptica por Salmonella no Typhi productora de β-lactamasas de espectro extendido que presentó una respuesta incompleta (definida como la persistencia de Salmonella en el líquido articular) al tratamiento inicial con cotrimoxazol y que posteriormente mejoró con ertapenem. La enfermedad se asoció al uso de un catéter venoso implantable. El 5% de los pacientes con gastroenteritis por Salmonella no Typhi desarrolla una bacteriemia. La endocarditis infecciosa y la artritis ha sido reportada en 1,4-5% de los casos y en menos de 1%; respectivamente.

Gastroenteritis por Salmonella spp. en tres lactantes asociada a contacto con tortugas acuáticas / Salmonella spp. gastroenteritis associated to pet turtles in three infants

Non-typhoidal salmonellosis is an important cause of acute diarrhea in children. Generally they are acquired by consumption of contaminated food, but contact with reptiles is an increasing cause of this zoonoses. We describe three pediatric cases of gastroenteritis by Salmonella (Montevideo, Newport and Pomona), related to having turtles as pets. In two cases, the bacteria were isolated from the patient’s stools and the turtle’s droppings. The same genetic subtype by PFGE was obtained in both isolates. All the children recovered. Information and public health measures should be undertaken to control this zoonoses which affects young children.

Las infecciones por Salmonella no tíficas, son una importante causa de diarrea aguda en niños. Generalmente adquiridas por alimentos contaminados, el contacto con animales, especialmente reptiles, también es responsable de esta zoonosis. Describimos tres casos de lactantes con gastroenteritis por Salmonella (S. Montevideo, S. Newport y S. Pomona), relacionados a contacto con tortugas mascotas. En dos de los casos se aisló Salmonella en las deposiciones de los niños y de las tortugas. En todos hubo proximidad entre los niños y los acuarios y/o tortugas, siendo probable la contaminación en la preparación de alimentos. El estudio de clonalidad por electroforesis de campo pulsado demostró el mismo subtipo genético en el aislado correspondiente al paciente y en el procedente de la mascota, lo cual confirmó la fuente zoonótica de los casos. Esta zoonosis debe ser abordada por las autoridades de salud y las sociedades científicas, ya que representa un importante riesgo para la salud, especialmente de niños pequeños.

PREVALENCE OF DRUG RESISTANCE AND VIRULENCE FEATURES IN Salmonella spp. ISOLATED FROM FOODS ASSOCIATED OR NOT WITH SALMONELLOSIS IN BRAZIL / Prevalência de resistência antimicrobiana e características de virulência em Salmonella spp. isoladas de alimentos associados ou não com salmonelose no Brasil

Salmonella is the most common etiological agent of cases and outbreaks of foodborne diarrheal illnesses. The emergence and spread of Salmonella spp., which has become multi-drug resistant and potentially more pathogenic, have increased the concern with this pathogen. In this study, 237 Salmonella spp., associated or not with foodborne salmonellosis in Brazil, belonging mainly to serotype Enteritidis, were tested for antimicrobial susceptibility and the presence of the virulence genes spvC, invA, sefA and pefA. Of the isolates, 46.8% were sensitive to all antimicrobials and 51.9% were resistant to at least one antimicrobial agent. Resistance to more than one antimicrobial agent was observed in 10.5% of the strains. The highest rates of resistance were observed for streptomycin (35.9%) and nalidixic acid (16.9%). No strain was resistant to cefoxitin, cephalothin, cefotaxime, amikacin, ciprofloxacin and imipenem. The invA gene was detected in all strains. Genes spvC and pefA were found in 48.1% and 44.3% of strains, respectively. The gene sefA was detected in 31.6% of the strains and only among S. Enteritidis. Resistance and virulence determinants were detected in Salmonella strains belonging to several serotypes. The high rates of antibiotic-resistance in strains isolated from poultry products demonstrate the potential risk associated with the consumption of these products and the need to ensure good food hygiene practices from farm to table to reduce the spread of pathogens relevant to public health.

Salmonella é o agente etiológico mais comumente envolvido em casos e surtos de doenças diarréicas de origem alimentar. A preocupação com este patógeno é, ainda, maior quando se verifica o surgimento e a disseminação de cepas multirresistentes e potencialmente mais patogênicas. Neste estudo, 237 cepas Salmonella spp., associadas ou não com casos ou surtos de salmonelose e pertencentes, principalmente, ao sorovar Enteritidis, foram avaliadas quanto ao perfil de susceptibilidade antimicrobiana e presença dos genes de virulência spvC, invA, sefA e pefA. Entre as cepas avaliadas, 46,8% foram sensíveis a todos os agentes antimicrobianos e 51,9% foram resistentes a pelo menos uma droga. Multirresistência foi observada em 10,5% das cepas. As maiores taxas de resistência foram observadas para estreptomicina (35,9%) e ácido nalidíxico (16,9%). Não foram detectadas cepas resistentes à cefoxitina, cefalotina, cefotaxima, amicacina, ciprofloxaxina e imipenem. O gene invA foi detectado em todas as cepas de Salmonella. Os genes spvC e pefA foram encontrados em 48,1% e 44,3% das cepas, respectivamente. O gene sefA foi detectado em 31,6% das cepas, estando presente somente entre as cepas de S. Enteritidis. Resistência antimicrobiana e marcadores de virulência foram detectados em cepas de Salmonella pertencentes a diversos sorovares. A alta taxa de resistência antimicrobiana verificada em cepas isoladas de frangos e derivados demonstra o potencial risco associado ao consumo destes produtos e a necessidade de se assegurar boas práticas de higiene em toda cadeia produtiva para reduzir a disseminação de patógenos relevantes para a saúde pública.

Anti-bacterial activity of Achatina CRP and its mechanism of action.

The physiological role of C-reactive protein (CRP), the classical acute-phase protein, is not well documented, despite many reports on biological effects of CRP in vitro and in model systems in vivo. It has been suggested that CRP protects mice against lethal toxicity of bacterial infections by implementing immunological responses. In Achatina fulica CRP is a constitutive multifunctional protein in haemolymph and considered responsible for their survival in the environment for millions of years. The efficacy of Achatina CRP (ACRP) was tested against both Salmonella typhimurium and Bacillus subtilis infections in mice where endogenous CRP level is negligible even after inflammatory stimulus. Further, growth curves of the bacteria revealed that ACRP (50 µg/mL) is bacteriostatic against gram negative salmonellae and bactericidal against gram positive bacilli. ACRP induced energy crises in bacterial cells, inhibited key carbohydrate metabolic enzymes such as phosphofructokinase in glycolysis, isocitrate dehydrogenase in TCA cycle, isocitrate lyase in glyoxylate cycle and fructose-1,6-bisphosphatase in gluconeogenesis. ACRP disturbed the homeostasis of cellular redox potential as well as reduced glutathione status, which is accompanied by an enhanced rate of lipid peroxidation. Annexin V-Cy3/CFDA dual staining clearly showed ACRP induced apoptosis-like death in bacterial cell population. Moreover, immunoblot analyses also indicated apoptosis-like death in ACRP treated bacterial cells, where activation of poly (ADP-ribose) polymerase-1 (PARP) and caspase-3 was noteworthy. It is concluded that metabolic impairment by ACRP in bacterial cells is primarily due to generation of reactive oxygen species and ACRP induced anti-bacterial effect is mediated by metabolic impairment leading to apoptosis-like death in bacterial cells.

A novel multiplex PCR for the simultaneous detection of Salmonella enterica and Shigella species

Salmonella enterica and Shigella species are commonly associated with food and water borne infections leading to gastrointestinal diseases. The present work was undertaken to develop a sensitive and reliable PCR based detection system for simultaneous detection of Salmonella enterica and Shigella at species level. For this the conserved regions of specific genes namely ipaH1, ipaH, wbgZ, wzy and invA were targeted for detection of Shigella genus, S. flexneri, S. sonnei, S. boydii and Salmonella enterica respectively along with an internal amplification control (IAC). The results showed that twenty Salmonella and eleven Shigella spp., were accurately identified by the assay without showing non-specificity against closely related other Enterobacteriaceae organisms and also against other pathogens. Further evaluation of multiplex PCR was undertaken on 50 natural samples of chicken, eggs and poultry litter and results compared with conventional culture isolation and identification procedure. The multiplex PCR identified the presence of Salmonella and Shigella strains with a short pre-enrichment step of 5 h in peptone water and the same samples were processed by conventional procedures for comparison. Therefore, this reported multiplex PCR can serve as an alternative to the tedious time-consuming procedure of culture and identification in food safety laboratories.

Salmonelosis neonatal: reporte de un caso y revisión de la literatura / Neonatal Salmonella infections: a case report and literature review

En Chile aún existe la salmonelosis como causal de enfermedad entérica, prevaleciendo el serotipo Enteritidis. En sepsis neonatal el germen más frecuente es Streptococcus grupo B (SGB); los bacilos Gram negativos entéricos ocupan el segundo lugar. La Salmonella spp. es infrecuente. Las vías de transmisión pueden ser hematógena, canal del parto, ascendente u horizontal. CASO CLÍNICO: Mujer sana, 31 años, embarazo de 39 semanas. Cultivo de SGB negativo. Presenta cuadro diarreico el día previo al parto, el cual fue vaginal, dilatación de cuatro horas, expulsivo de 15 minutos, líquido amniótico claro, destaca temperatura (T°) intraparto de 38,3°C. Recién nacido (RN)sexo masculino, adecuado para la edad gestacional, Apgar 9/9,con T° rectal 38,1°C al nacer. Al segundo día de vida presenta deposiciones líquidas verdosas con estrías de sangre, descenso de peso de 10,6 por ciento (367,82 gr) y T° rectal 37,7°C. Ingresa a neonatología, destacando Proteína C Reactiva elevada de 2,7 mg/dL. Por persistir cuadro se solicitan cultivos previo a antibioterapia con Ampicilina y Gentamicina. Test APT-Downey positivo, cultivo orina y líquido cerebroespinal negativos, hemocultivo y coprocultivo positivo a Salmonella tipo D subtipo Panamá. Evoluciona favorablemente, es dado de alta al noveno día con diagnóstico de sepsis por Salmonella tipo D connatal. Coprocultivo de madre positivo para Salmonella. DISCUSIÓN: La prevalencia de infecciones por Salmonella se ha incrementado en neonatos. Es importante realizar prevención durante el embarazo además de un diagnóstico y tratamiento precoz. Se debe considerar este agente según factores de riesgo y como diagnóstico diferencial de hemorragia digestiva baja en el RN...

Salmonella infections are still a cause of entericdisease in Chile, with a predominance of the Enteritidis serotype. In neonatal sepsis the most frequent etiology is Group B Streptococcal (GBS) infection; enteric Gram-negative bacilli occupy second place. Salmonella spp. is infrequent. The transmission routes can be hematogenous, by birth canal, vertical, or horizontal. CASE REPORT: Healthy 31 year old female, 39 week pregnancy. Negative GBS culture. Presents with diarrhea the day before labor, with vaginal delivery, four hour dilation period,15 minute expulsion period, clear amniotic fluid, intra delivery temperature (T°) of 38.3°C. Male, adequate for gestational age newborn, Apgar 9/9, with rectal T° of 38.1°C at birth. During second day of life, presents green liquid stools with blood streaks, weight loss of 10.6 percent (367.82 gr), and rectal T° of 37.7°C. Patient is admitted to neonatology service, where he presents elevated C-Reactive Protein of 2.7 mg/dL. Cultures were taken due to persistent findings, before antibiotic therapy with Ampicillinand Gentamicin. Positive APT-Downey test, negative urine and cerebrospinal fluid cultures, positive blood and stool cultures for type D, subtype Panama Salmonella. Favorable evolution, discharged on day nine with diagnosis of sepsis due to connatal type D Salmonella. Mother’s stool culture is positive for same bacteria. DISCUSSION: The prevalence of Salmonella infections has increased in neonates. Prevention during pregnancy, along with early diagnosis and treatment, are important. This agent should be considered according to risk factors, and as a differential diagnosis of lower gastrointestinal bleeding in newborns...

Salmonelloses in the State of Rio Grande do Sul, southern Brazil, 2002 to 2004

Salmonella has been identified as the main aetiological agent responsible for foodborne diseases in several countries worldwide, including Brazil. In the State of Rio Grande do Sul (RS), southern Brazil, previews studies analysed official foodborne illnesses data, identifying Salmonella as the main bacterial agent of foodborne diseases during the period of 1997 to 2001. The present study aimed to analyse the official epidemiological data on salmonelloses occurred in the State of RS, during the period of 2002 to 2004. Even though data on recent salmonelloses were available, only data concerning the period comprising in 2002 to 2004 were analysed because the official worksheet records presented more consistent information about the salmonellosis outbreaks. Results indicated that, among the 624 foodborne outbreaks officially investigated, 202 (32.37%) were confirmed as salmonellosis. Among them 23,725 people were involved, 4,148 became sick, 1,878 were hospitalized and one person died. The season with the highest incidence of salmonelloses was spring, and the most affected age group was composed of people aged between 20 to 49 years old (56.66%). Animal origin foods -especially eggs and meat products -were very often involved with the outbreaks, however homemade mayonnaise was identified as the main food vehicle for salmonelloses (53.51%). The majority of the cases occurred inside private homes (55.81%) and food services (12.1%), and the main factors contributing to the occurrence of the outbreaks were the consumption of products without sanitary inspection (26.7%) and exposure of food at room temperature for more than two hours (18.58%). Similarly to what was previously reported for the period of 1997 to 2001, Salmonella spp. was the most prevalent foodborne disease agent in the State of RS during the years of 2002 to 2004.