Stress tolerant virulent strains of Cronobacter sakazakii from food

BACKGROUND: Cronobacter sakazakii is considered as an emerging foodborne pathogen. The aim of this study was to isolate and characterize virulent strains of Cronobacter sakazakii from food samples of Bangladesh. RESULT: Six (6) Cronobacter sakazakii was isolated and identified from 54 food samples on the basis of biochemical characteristics, sugar fermentation, SDS-PAGE of whole cell protein, plasmid profile and PCR of Cronobacter spp. specific genes (esak, gluA, zpx, ompA, ERIC, BOX-AIR) and sequencing. These strains were found to have moderately high antibiotic resistance against common antibiotics and some are ESBL producer. Most of the C. sakazakii isolates were capable of producing biofilm (strong biofilm producer), extracellular protease and siderophores, curli expression, haemolysin, haemagglutinin, mannose resistant haemagglutinin, had high cell surface hydrophobicity, significant resistance to human serum, can tolerate high concentration of salt, bile and DNase production. Most of them produced enterotoxins of different molecular weight. The isolates pose significant serological cross-reactivity with other gram negative pathogens such as serotypes of Salmonella spp., Shigella boydii, Shigella sonnei, Shigella flexneri and Vibrio cholerae. They had significant tolerance to high temperature, low pH, dryness and osmotic stress. CONCLUSION: Special attention should be given in ensuring hygiene in production and post-processing to prevent contamination of food with such stress-tolerant virulent Cronobacter sakazakii.

First clinical isolates of Cronobacter spp. (Enterobacter sakazakii) in Argentina: characterization and subtyping by pulsed-field gel electrophoresis / First clinical isolates of Cronobacter spp. (Enterobacter sakazakii) in Argentina: characterization and subtyping by pulsed-field gel electrophoresis.

Cronobacter species are opportunistic pathogens associated with severe infections in neonates and immunocompromised infants. From January 2009 through September 2010, two cases of neonatal infections associated with Cronobacter malonaticus and one case associated with Cronobacter sakazakii, two of them fatal, were reported in the same hospital. These are the first clinical isolates of Cronobacter spp. in Argentina. The objective of this work was to characterize and subtype clinical isolates of Cronobacter spp. in neonate patients, as well as to establish the genetic relationship between these isolates and the foodborne isolates previously identified in the country. Pulsed-field gel electrophoresis analysis showed a genetic relationship between the C. malonaticus isolates from two patients. Different results were found when the pulsed-field gel electrophoresis patterns of clinical isolates were compared with those deposited in the National Database of Cronobacter spp.

Work of adhesion of dairy products on stainless steel surface

The adhesion of the solids presents in food can difficult the process of surface cleaning and promotes the bacterial adhesion process and can trigger health problems. In our study, we used UHT whole milk, chocolate based milk and infant formula to evaluate the adhesion of Enterobacter sakazakii on stainless steel coupons, and we determine the work of adhesion by measuring the contact angle as well as measured the interfacial tension of the samples. Inaddition we evaluated the hydrophobicity of stainless steel after pre-conditioning with milk samples mentioned. E. sakazakii was able to adhere to stainless steel in large numbers in the presence of dairy products. The chocolate based milk obtained the lower contact angle with stainless steel surface, higher interfacial tension and consequently higher adhesion work. It was verified a tendency of decreasing the interfacial tension as a function of the increasing of protein content. The pre-conditioning of the stainless steel coupons with milk samples changed the hydrophobic characteristics of the surfaces and became them hydrophilic. Therefore, variations in the composition of the milk products affect parameters important that can influence the procedure of hygiene in surface used in food industry.

Primer aislamiento de Cronobacter spp (Enterobacter sakazakii) en fórmula láctea en polvo producida en Chile / First isolation of Cronobacter spp (Enterobacter sakazakii) in powdered baby formula in Chile

La familia Enterobacteriaceae contempla agentes comunes en las enfermedades transmitidas por los alimentos. De esta familia Cronobacter spp, es considerado un patógeno que afecta principalmente a recién nacidos, los que pueden adquirirla a través de fórmulas lácteas infantiles en polvo contaminadas. Objetivo: Pesquisar Cronobacter spp, en una fórmula láctea en polvo producida en Chile. Material y método: En julio de 2008, se obtuvieron 80 muestras desde una planta ubicada en la Región de Los Lagos. Para el aislamiento de Cronobacter spp, se utilizó el método descrito en la norma ISO/TS 22964. Las muestras fueron analizadas en el Laboratorio de Alimentos del Instituto de Medicina Preventiva Veterinaria de la Universidad Austral de Chile. Resultados: Del total de muestras analizadas, el 5 por ciento (4 / 80) fueron confirmadas como Cronobacter spp, constituyendo así el primer reporte de esta bacteria en Chile. Conclusión: Cronobacter spp, está presente en una fórmula láctea en polvo producida en Chile. Su presencia en este producto representa un riesgo que no es considerado en el actual Reglamento Sanitario de los Alimentos de nuestro país.

The family Enterobacteriaceae includes agents that are commonly transmitted through food. Within this family, Cronobacter spp, is considered to be a pathogen that primarily affects newborns, which can acquire it through contaminated powdered formula. Objective: Isolate Cronobacter spp, in a powdered milk formula produced in Chile. Material and method: In July of 2008, 80 samples were obtained from a factory in the Los Lagos Region. To isolate Cronobacter spp, the methods described in the ISO/TS 22964 specifications were used. The samples were analyzed at the Food Laboratory at the Institute of Preventative Veterinary Medicine and the Universidad Austral de Chile. Results: Of all analyzed samples, 5 percent (4/80) were contaminated with Cronobacter spp, which constitutes the first report of this bacterium in Chile. Conclusion: Cronobacter spp is present in powdered baby formula produced in Chile. It’s presence in this product represents a risk that is not considered in the current food safety standards in this country.

Occurrence of Enterobacter sakazakii in some meat products sold in Assiut governorate

A total number of 75 samples including 25 samples each of luncheon, minced frozen beef and sausage were collected from Assiut city [Upper Egypt] and examined bacteriologically for the presence of E. sakazakii and other Enterobacteriaceae genera and species by using the FDA enrichment procedure. In addition, a polymerase chain reaction [PCR] method for the rapid detection of E. sakazakii was adapted by using a set of primers designed from a region of the 16S ribosomal RNA gene. E. sakazakii was detected in 7 [28%] of sausage, but none of the luncheon and minced frozen beef samples were positive for E. sakazakii. Moreover, one false positive isolate was observed with FDA method. In contrast, PCR was highly sensitive and specific to E. sakazakii. E. cloacae were isolated from all samples, while E. agglomerans was detected only in luncheon samples. Also, 43 isolates related to family Enterobacteriaceae could be isolated including Citrobacter freundii, Escherichia coli, Hafnia alvei, Klebsiella pneumoniae, K. oxytoca, Kozaenae, K. planticola and Serratia marcescens. The public health importance of E. sakazakii and suggested control measures were discussed

Aislamiento e identificación de Enterobacter sakazakii en lactarios de Bogotá / Isolation and identification of Enterobacter sakazakii in milk feeders of Bogotá, D. C

Introducción. Enterobacter sakazakii es un patógeno oportunista emergente de alto riesgo, responsable de meningitis grave y enterocolitis necrosante. El principal vehículo de transmisión de esta bacteria son los productos infantiles deshidratados, debido a su contaminación después del tratamiento térmico. Objetivo. Identificar cepas de E. sakazakii en muestras de lactarios recolectadas en la ciudad de Bogotá, D.C. Materiales y métodos. Se analizaron 222 muestras de 9 lactarios, de superficies estériles y no estériles, utensilios empleados para la preparación de biberones y operarios. Se realizó recuento de coliformes totales y detección de E. sakazakii utilizando el protocolo propuesto por la Food and Drug Administration y por el Sistema Automático Bax® Dupont Qualicon. Resultados. De las 222 muestras recolectadas en las clínicas de Bogotá, se reportó que 27,4% (61) de las muestras analizadas presentaban coliformes totales; se detectó la presencia de E. sakazakii en 3,6% por el método automatizado de PCR BAX Dupont a partir de muestras de biberones y superficies. Conclusiones. Se demostró la presencia de E. sakazakii en lactarios en Colombia. Debido a que este microorganismo es un patógeno oportunista de alto riesgo para neonatos y que está asociado a las prácticas higiénicas en los lactarios, la información de este estudio puede ser útil para la toma de medidas profilácticas que reduzcan el riesgo de contaminación con este patógeno para la población infantil y, también, aporta información importante para la salud pública.

Introduction: Enterobacter sakazakii is an emergent opportunistic pathogen of high risk responsible of severe meningitis and necrotizing enterocolitis in neonates and infants with underlying medical conditions. One of the principal transmission vehicles for the transmission of these bacteria, is the infant dehydrated formula after exposing them to the heating treatment. Objective: To identify strains of E. sakazakii in milk feeders’ samples from Bogotá. Materials and methods: 222 samples from 9 milk feeders including sterile and non sterile surfaces, utensils used for the formula preparation and food handlers were analyzed. Total coliforms counts and identification of E. sakazakii was done using the FDA protocol and the automatic system Bax ® Dupont Qualicon. Results: From de 222 samples collected from hospitals in Bogotá, it was reported that 27.4% (61) had total coliforms, and the presence of E. sakazakii was detected in 3.6% (8) from one feeding bottle and surfaces. Conclusion: The presence of E. sakazakii strains was reported in Colombian milk feeders. Because this microorganism is a high risk opportunistic pathogen for newborn infants, usually associated with hygiene practices in milk feeders, the information of this research could be useful to develop preventive measurements to reduce the risk of contamination in the infant population and provides important public health information.

Primer estudio de Enterobacter sakazakii en alimentos en Cuba / First study on Enterobacter sakazakii in foodstuffs in Cuba

Enterobacter sakazakii es uno de los microorganismos patógenos emergentes que han hecho su aparición en los últimos años, fundamentalmente como contaminante ocasional de las fórmulas infantiles en polvo. En países en vías de desarrollo no existen suficientes investigaciones sobre este microorganismo, en Cuba este constituye el primer estudio realizado. Conocer la presencia de E. sakazakii en muestras de leche en polvo de importación. Se analizaron 60 muestras de leche en polvo, entera y descremada, provenientes de nueve países, se siguió la técnica recomendada por autoridades reguladoras de EE.UU., con la inclusión de pruebas bioquímicas convencionales como alternativa antes de aplicar el sistema de identificación API 20E. Se empleó el agar hierro Kligler y el agar citrato de Simmons; en aquellas cepas con imagen sugestiva de Enterobacter se comprobó la obtención de triptofano a partir de indol, reacción de Voges Proskauer y rojo de metilo, descarboxilación de lisina y ornitina, dihidrólisis de la arginina, producción de ácido de sacarosa, dulcitol, adonitol, rafinosa y sorbitol. Se obtuvo crecimiento de enterobacterias en 26 muestras. Una sola cepa dio resultado presuntivo de E. sakazakii por pruebas bioquímicas, la misma se confirmó por API 20E para 1,6 por ciento de positividad. En general la calidad microbiológica de las muestras de leche estudiadas fue buena. La técnica empleada para determinar E. sakazakii en muestras de leche en polvo, con la inclusión de pruebas bioquímicas convencionales, es factible de realizar en Cuba, para minimizar los costos asociados a la utilización de API 20E. Sería importante continuar estos estudios en áreas hospitalarias, especialmente aquellas donde se preparan fórmulas lácteas para recién nacidos.

Enterobacter sakazakii is an emerging pathogen that has been isolated in milk powder preparations for infant in the last few years. Practically there is no research works about this microorganism in developing countries; in Cuba this is the first study. To detect the presence of E. sakazakii in imported milk powder samples. Sixty samples of whole and skimmed powdered milk imported from 9 countries were analyzed. Before applying API 20E Kit, the recommended technique by US regulatory bodies including conventional biochemical tests was used. Kligler´s iron agar and Simmons´s citrate agar were employed; other tests such as obtaining of triptophane from indole, Voges Proskauer reaction, methyl red, lysine and ornitine decarboxylation, arginine dihydrolysis, production of sucrose acid, dulcit, adonit, raffinose and sorbitol were performed in presumptive Enterobacter strains. Enterobacteria were isolated in 26 samples. Just one strain was classified as E. sakasakii using the traditional biochemical tests and further confirmed by API 20E for 1.6 percent possitivity of the sample. Generally speaking, the microbiological quality of powered milk samples was good. The technique used to determine E. sakazakii in powered milk samples, including conventional biochemical tests, is feasible to be performed in Cuba in order to reduce costs inherent to the use of API 20E. It is important to conduct these studies in hospital settings, particularly in those areas where milk formulae for neonates are prepared.

Enterobacter sakazakii in infants: novel phenomenon in India.

E. sakazakii has been implicated in necrotizing enterocolitis, bloodstream and central nervous system infections, with mortality rates of 40-80%. Two cases of E. sakazakii infections; one preterm very low birth weight neonate with meningitis and a two month infant with bacteraemia, are described for the first time in India. The first baby succumbed to the infection while the other responded to appropriate therapy. Powdered infant milk formulae have been implicated in causing neonatal infections and the first baby was on formula feed with classic signs of sepsis and meningitis. The second infant was on breast feed and probably developed nosocomial E. sakazakii bacteraemia.