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1.
Lett Appl Microbiol ; 76(9)2023 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-37660241

RESUMO

Characterizing microorganisms according to different criteria is useful when investigating sources of microbiological contamination in the pharmaceutical industry. The aim of this study was to characterize 38 Acinetobacter baumannii complex strains isolated from a biopharmaceutical industry by 16S rRNA sequencing, matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF/MS), multilocus sequence typing (MLST), antimicrobial susceptibility profile, biofilm formation, and sensibility to disinfectants. Thirty-three (86.9%) strains were identified by 16S rRNA gene sequencing as A. seifertii/pitti/nosocomialis/lactucae, four (10.5%) as A. baumannii, and one (2.6%) as A. vivianii/courvalini. MALDI-TOF/MS did not identify one strain, and incorrectly identified 30/37 (81.1%) strains as A. baumannii. Strains were assigned to 12 different STs, of which nine were newly defined in this study (STs 2091-2099). Twenty-six (68.4%) strains showed resistance to amikacin and gentamicin. Thirty-three (86.8%) strains were classified as moderately or strongly adherent on polystyrene. Alcohol 70%/15 min and quaternary ammonium 0.08%/20 min were not able to eliminate the biofilm formed, but sodium hypochlorite 0.1%/15 min was efficient. In conclusion, improved methods are needed to improve the identification of Acinetobacter strains in pharmaceutical industries. This organism is of particular concern as it forms recalcitrant biofilms, leading to persistence in the manufacturing environment and increased risk of product contamination.


Assuntos
Acinetobacter baumannii , Tipagem de Sequências Multilocus , RNA Ribossômico 16S/genética , Acinetobacter baumannii/genética , Amicacina , Preparações Farmacêuticas
2.
Food Microbiol ; 111: 104191, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36681390

RESUMO

Species identification and growth rates for a collection of Cronobacter strains from clinical and non-clinical sources have been previously reported. However, advancements in DNA sequencing-based identification methods now allow for more accurate identification. Here we report the sequence types (STs) for 24 strains of Cronobacter sakazakii and examine any possible correlation between sequence type and growth rate, which could influence risk through greater pathogen multiplication and reach of infectious doses during time between formula preparation and feeding. The most common clonal complexes (CCs) identified were C. sakazakii CC1 and CC4. CC1 strains belonged to ST1 (n = 8) and ST391 (n = 1), while CC4 included ST4 (n = 4), ST255 (n = 1) and ST295 (n = 1). Three strains were found to belong to CC100 and two were found to belong to ST64. The remaining STs identified were represented by single strains. CC4 strains have a slightly not significant tendency for faster growth rates at 25 °C; however, the small sample size suggests that more strains need to be analysed to determine if this is a true result. In conclusion, the growth rates of C. sakazakii strains do not appear to be strongly correlated to ST.


Assuntos
Cronobacter sakazakii , Cronobacter sakazakii/genética , Cronobacter sakazakii/crescimento & desenvolvimento , Fórmulas Infantis/microbiologia , Análise de Sequência de DNA
3.
Lett Appl Microbiol ; 74(6): 1008-1015, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35263446

RESUMO

This is the first report of acute deaths in five European brown hares (Lepus europaeus) attributed to mucoid and necrotizing typhlocolitis caused by genetically different Cronobacter (C.) turicensis strains in northeastern Austria. As this opportunistic pathogen is mainly known for causing disease in immunocompromised humans and neonates, this previously unrecognized potential for a spill over from a wildlife reservoir to humans warrants further attention.


Assuntos
Cronobacter , Lebres , Animais , Animais Selvagens , Surtos de Doenças/veterinária , Humanos , Recém-Nascido
4.
J Dairy Sci ; 104(11): 11348-11367, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34364644

RESUMO

Members of the Cronobacter genus include food-borne pathogens that can cause infections in infants, with a mortality rate as high as 40 to 80%. The high fatality rate of Cronobacter and its isolation from numerous types of food, especially from powdered infant formula, demonstrate the serious nature of this organism. The source tracking of Cronobacter spp. and the analysis of high-frequency species from different sources are helpful for a more targeted control. Furthermore, the persistence during food processing and storage may be attributed to strong resistance of Cronobacter spp. to environment stresses such as heat, pH, and desiccation. There are many factors that support the survival of Cronobacter spp. in harsh environments, such as some genes, regulatory systems, and biofilms. Advanced detection technology is helpful for the strict monitoring of Cronobacter spp. In addition to the traditional heat treatment, many new control techniques have been developed, and the ability to control Cronobacter spp. has been demonstrated. The control of this bacteria is required not only during manufacture, but also through the selection of packaging methods to reduce postprocessing contamination. At the same time, the effect of inactivation methods on product quality and safety must be considered. This review considers the advances in our understanding of environmental stress response in Cronobacter spp. with special emphasis on its implications in food processing.


Assuntos
Cronobacter sakazakii , Cronobacter , Animais , Cronobacter/genética , Contaminação de Alimentos/análise , Microbiologia de Alimentos , Fórmulas Infantis , Pós
5.
BMC Public Health ; 20(1): 1322, 2020 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-32867725

RESUMO

BACKGROUND: Kitchen sponges are a major source of cross-contamination as they can transfer foodborne pathogens, infectious agents and spoilage causing microorganisms to food contact surfaces. Several studies have revealed that university students adopt poor practices regarding food safety, hygiene, and the handling of kitchen cleaning equipment. METHODS: A total of fifty kitchen sponges were collected along with a questionnaire addressing social demographics and kitchen sponge usage by students living at the University of Sharjah dormitories. The effect of storage (3 and 10 days) on the microbial population of kitchen sponges at room temperature (21 °C) was assessed. Enterobacteriaceae isolated from sponges were identified and their antibiotic resistance determined. RESULTS: Student responses revealed that kitchen sponges used to clean food contact surfaces were also used to clean the oven (32%), sink (26%), refrigerator (10%), and to clean spills on the floor (4%). Kitchen sponges contained high counts of mesophilic aerobic bacteria (7.9 log10/cm3), coliform (7.2 log10/cm3), Enterobacteriaceae (7.3 log10/cm3) and yeasts and molds (7.0 log10/cm3). After storage of the sponges at room temperature (21 °C) for 3 and 10 days, the number of mesophilic aerobic bacteria, coliform, Enterobacteriaceae and yeasts and molds decreased by 0.4 and 1.3 log10/cm3, 0.7 and 1.4 log10/cm3, 0.4 and 1.1 log10/cm3, and 0.6 and 1.3 log10/cm3, respectively. The most frequently isolated Enterobacteriaceae were Enterobacter cloacae (56%) and Klebsiella oxytoca (16%). All E. cloacae isolates were resistant to amoxicillin, cefalotin, cefoxitin and cefuroxime axetil. CONCLUSIONS: This study showed that students living in dormitories lacked good hygienic practices and were at increased risk of food poisoning. Kitchen sponges were highly contaminated with potentially pathogenic bacteria which could be transferred from the general kitchen environment to food contact surfaces and consequently lead to food contamination.


Assuntos
Enterobacteriaceae/isolamento & purificação , Contaminação de Alimentos/estatística & dados numéricos , Manipulação de Alimentos/estatística & dados numéricos , Microbiologia de Alimentos , Inocuidade dos Alimentos , Estudantes/psicologia , Universidades/estatística & dados numéricos , Adulto , Contagem de Colônia Microbiana , Feminino , Humanos , Masculino , Estudantes/estatística & dados numéricos , Emirados Árabes Unidos , Adulto Jovem
6.
Emerg Infect Dis ; 25(3): 515-522, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30789137

RESUMO

Cronobacter sakazakii has been documented as a cause of life-threating infections, predominantly in neonates. We conducted a multicenter study to assess the occurrence of C. sakazakii across Europe and the extent of clonality for outbreak detection. National coordinators representing 24 countries in Europe were requested to submit all human C. sakazakii isolates collected during 2017 to a study center in Austria. Testing at the center included species identification by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, subtyping by whole-genome sequencing (WGS), and determination of antimicrobial resistance. Eleven countries sent 77 isolates, including 36 isolates from 2017 and 41 historical isolates. Fifty-nine isolates were confirmed as C. sakazakii by WGS, highlighting the challenge of correctly identifying Cronobacter spp. WGS-based typing revealed high strain diversity, indicating absence of multinational outbreaks in 2017, but identified 4 previously unpublished historical outbreaks. WGS is the recommended method for accurate identification, typing, and detection of this pathogen.


Assuntos
Cronobacter sakazakii , Infecções por Enterobacteriaceae/epidemiologia , Infecções por Enterobacteriaceae/microbiologia , Antibacterianos/farmacologia , Cronobacter sakazakii/classificação , Cronobacter sakazakii/efeitos dos fármacos , Cronobacter sakazakii/genética , Farmacorresistência Bacteriana , Infecções por Enterobacteriaceae/história , Europa (Continente)/epidemiologia , Genoma Bacteriano , Genômica/métodos , História do Século XXI , Humanos , Recém-Nascido , Masculino , Testes de Sensibilidade Microbiana , Tipagem Molecular , Tipagem de Sequências Multilocus , Filogenia , Vigilância em Saúde Pública , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Sequenciamento Completo do Genoma
7.
Crit Rev Food Sci Nutr ; 59(20): 3320-3333, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-29993263

RESUMO

Antibiotics are a key tool used nowadays in health care industry to fight against bacterial infections; however, repeated antibiotic use or misuses, have led to bacterial resistance, causing significant threats for many people with common bacterial infections. The use of probiotics to enhance gastrointestinal health has been proposed for many years. In recent years, there has been an increasing interest in the use of probiotic bacteria as alternatives for antibiotics for preventing or treating various intestinal infections. Several important underlying mechanisms responsible for the antagonistic effects of probiotics on different microorganisms include: (1) competitive exclusion for adhesion sites and nutritional sources; (2) secretion of antimicrobial substances; (3) enhancement of intestinal barrier function; and (4) immunomodulation. However, their mode of action is not very well understood and therefore a clearer understanding of these mechanisms is necessitated. This will enable appropriate probiotic strains to be selected for particular applications and may reveal new probiotic functions. The goal of this review was to highlight some studies from literature describing the probiotic interaction with several major foodborne pathogens, as well as explore the mechanisms for such probiotic-pathogen interaction. The review will conclude by presenting future perspective and challenges of probiotic application in food products.


Assuntos
Infecções Bacterianas/prevenção & controle , Doenças Transmitidas por Alimentos/prevenção & controle , Trato Gastrointestinal/microbiologia , Probióticos/uso terapêutico , Antibacterianos , Antibiose , Humanos
8.
Antonie Van Leeuwenhoek ; 112(3): 435-450, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30315374

RESUMO

Cronobacter malonaticus is a member of the genus Cronobacter which is considered an opportunistic pathogen. The significance of C. malonaticus has recently increased since it was documented to be involved in several serious neonatal infections. However, the virulence factors of C. malonaticus including their ability to adhere, invade and overcome host barriers have not been studied before. Unlike previous Cronobacter research, this study is mainly focused on C. malonaticus and is aimed to investigate its virulence characteristics that enable this species to cause adult and neonatal infections. Altogether, 20 strains were included in this study (19 clinical and one environmental strain). Our data showed that the clinical C. malonaticus has an ability to adhere and invade Caco-2, HBMEC, A549 and T24 cell lines. Moreover, the result showed that certain strains of C. malonaticus (including 1827 and 2018) were able to persist well in macrophages. However, ST7 strains 1827 and 2018 proved to be the most invasive strains among all used strains. The CDC strain 1569 (ST307) which was isolated from the blood of a fatal neonatal case showed also significant results in this study as it was able to invade all used human cells and survive and replicate within microphages. Finally, the findings of this study confirm the potential ability of C. malonaticus to cause serious infections in neonates or adults such as necrotising enterocolitis, meningitis, bacteraemia, pneumonia and urinary tract infection.


Assuntos
Aderência Bacteriana , Cronobacter/isolamento & purificação , Cronobacter/patogenicidade , Endocitose , Infecções por Enterobacteriaceae/microbiologia , Linhagem Celular , Células Epiteliais/microbiologia , Humanos , Macrófagos/microbiologia , Modelos Biológicos , Virulência
9.
J Dairy Sci ; 101(8): 6915-6926, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29729917

RESUMO

The air in a powdered infant formula (PIF) factory is a potential transfer medium for microorganisms. In this study, air samples from 6 main processing areas, almost covering the whole PIF processing line and 1 outdoor location, were collected from a PIF manufacturing plant during the winter and summer periods. A cultivation-based and an Illumina (San Diego, CA) high-throughput 16S rRNA sequencing method was used to investigate the community structures and distributions of bacteria in the air. High microbial diversity (25 genera, 56 species), with a dominant community including Staphylococcus, Bacillus, Acinetobacter, and Kocuria, was found by the cultivation-based method. Moreover, 104 genera were obtained from all samples by high-throughput sequencing methods. Lactococcus (32.3%), Bacillus (29.6%), and Staphylococcus (14.0%) were the preponderant genera. The indices from high-throughput sequencing results indicated that the bacterial community of the air samples was highly diverse. Significant differences in the diversity and distribution at 6 sampling locations were revealed using the 2 methods. In particular, the packaging process contained the highest proportion (39.4%) of isolated strains. The highest diversity in bacterial community structure was found in the outdoor location. More bacterial isolates and higher community diversity were observed in the summer samples compared with the winter samples. In addition, some pathogens, such as Acinetobacter baumannii, Bacillus cereus, and Staphylococcus cohnii, were mainly found in the large bag filling process, can filling, and packaging process areas. The present study provides greater insight into the microbial community and identifies potential sources of air contamination in PIF production environments and can serve as a guide to reduce the risk of microbial contamination in the production of PIF.


Assuntos
Sequenciamento de Nucleotídeos em Larga Escala/métodos , Fórmulas Infantis/microbiologia , RNA Ribossômico 16S/análise , Animais , Bactérias , Humanos , Lactente , Recém-Nascido , Pós
10.
BMC Microbiol ; 16(1): 146, 2016 07 11.
Artigo em Inglês | MEDLINE | ID: mdl-27401027

RESUMO

BACKGROUND: Microbiological criteria applied to powdered infant formula (PIF) require the absence of all Cronobacter spp. Consequently, misidentification of isolates from finished products can lead to significant financial losses for manufacturers and could increase the risk of neonatal infection. Biochemical identification of suspect isolates using commercially available test panels is recommended for use by PIF manufacturers by both the US FDA and ISO standard methods for Cronobacter species; however, phenotyping can be unreliable, particularly for a genus such as Cronobacter where the taxonomy has been subject to frequent changes. This study compared the predicted identification by commonly used phenotyping kits (API20E and ID32E) for over 240 strains of Cronobacter from diverse sources, which had been identified using DNA sequence analysis. In 2015, the databases associated with the API20E and ID32E biochemical test panels were updated, including the recognition of the Cronobacter genus. Thus, the identifications from multiple versions the databases were compared to each other and to identifications based on DNA sequencing methods. RESULTS: Using previous versions of the API20E database, 90.0 % of strains (216/240) resulted in a match for the species identification; however, version 5.0 produced matches for only 82.3 % of strains (237/288). Similarly, the update to version 4.0 in the ID32E database caused the percentage of matches to drop from 88.9 % (240/270) to 43.2 % (139/322). A smaller study showed that the Vitek GN system identified all 14 strains, belonging all seven Cronobacter species, as members of the 'C. sakazakii group,' but also attributed three strains of Franconibacter helveticus and F. pulveris to this group. In silco analysis of a PCR-based method targeting ompA predicted that amplification would only occur with Cronobacter species and this method may be a feasible alternative to biochemical phenotyping. CONCLUSIONS: These results indicate that commercially available biochemical test panels are not sufficiently reliable for speciation of Cronobacter isolates. Although DNA-sequence based methods would be the more reliable approach; however, this is not currently feasible for many food microbiology laboratories. Instead, a previously published PCR-based method targeting ompA is suggested as an alternative for identification of Cronobacter species based on in silico analysis.


Assuntos
Técnicas de Tipagem Bacteriana/métodos , Cronobacter/classificação , Cronobacter/fisiologia , Proteínas da Membrana Bacteriana Externa/genética , Técnicas de Tipagem Bacteriana/instrumentação , Classificação , Simulação por Computador , Cronobacter/isolamento & purificação , DNA Bacteriano/genética , Bases de Dados de Ácidos Nucleicos , Contaminação de Alimentos/análise , Microbiologia de Alimentos , Genótipo , Fórmulas Infantis/microbiologia , Fenótipo , Reação em Cadeia da Polimerase/métodos , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
11.
Microb Pathog ; 90: 55-63, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26616163

RESUMO

Cronobacter sakazakii is the most frequently clinically isolated species of the Cronobacter genus. However the virulence factors of C. sakazakii including their ability to overcome host barriers remains poorly studied. In this study, ten clinical isolates of C. sakazakii were assessed for their ability to invade and translocate through human colonic carcinoma epithelial cells (Caco-2) and human brain microvascular endothelial cells (HBMEC). Their ability to avoid phagocytosis in human macrophages U937 and human brain microglial cells was investigated. Additionally, they were tested for serum sensitivity and the presence of the Cronobacter plasminogen activation gene (cpa) gene, which is reported to confer serum resistance. Our data showed that the clinical C. sakazakii strains invaded and translocated through Caco-2 and HBMEC cell lines and some strains showed significantly higher levels of invasion and translocation. Moreover, C. sakazakii was able to persist and even multiply in phagocytic macrophage and microglial cells. All strains, except one, were able to withstand human serum exposure, the single serum sensitive strain was also the only one which did not encode for the cpa gene. These results demonstrate that C. sakazakii clinical isolates are able to overcome host barriers and evade the host immune response indicating their capacity to cause diseases such as necrotizing enterocolitis (NEC) and meningitis. Our data showed for the first time the ability of C. sakazakii clinical isolates to survive and multiply within human microglial cells. Additionally, it was shown that C. sakazakii clinical strains have the capacity to translocate through the Caco-2 and HBMEC cell lines paracellularly.


Assuntos
Cronobacter sakazakii/imunologia , Cronobacter sakazakii/patogenicidade , Infecções por Enterobacteriaceae/imunologia , Infecções por Enterobacteriaceae/microbiologia , Células CACO-2 , Técnicas de Cultura de Células , Linhagem Celular , Cronobacter sakazakii/genética , Cronobacter sakazakii/isolamento & purificação , Células Endoteliais/microbiologia , Infecções por Enterobacteriaceae/genética , Células Epiteliais/microbiologia , Humanos , Macrófagos/imunologia , Macrófagos/microbiologia , Macrófagos/patologia , Meningite/microbiologia , Testes de Sensibilidade Microbiana , Microglia/microbiologia , Microglia/patologia , Fatores de Virulência/genética , Fatores de Virulência/imunologia , Fatores de Virulência/metabolismo
12.
Appl Environ Microbiol ; 81(16): 5430-9, 2015 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-26048942

RESUMO

Cronobacter spp. (formerly defined as Enterobacter sakazakii) are opportunistic bacterial pathogens of both infants and adults. In this study, we analyzed 70 Cronobacter isolates from powdered infant formula (PIF) and an infant formula production facility in China to determine possible contamination routes. The strains were profiled by multilocus sequence typing (MLST), pulsed-field gel electrophoresis (PFGE), PCR-based O-antigen serotyping, and ompA and rpoB sequence analyses. The isolates were primarily Cronobacter sakazakii (66/70) or Cronobacter malonaticus (4/70). The strains were divided into 38 pulsotypes (PTs) using PFGE and 19 sequence types (STs) by MLST. In contrast, rpoB and ompA sequence analyses divided the strains into 10 overlapping clusters each. PCR serotyping of the 66 C. sakazakii and 4 C. malonaticus strains resulted in the identification of four C. sakazakii serotypes (O1, O2, O4, and O7) and a single C. malonaticus serotype, O2. The dominant C. sakazakii sequence types from PIF and an infant formula production factory in China were C. sakazakii clonal complex 4 (CC4) (n = 19), ST1 (n = 14), and ST64 (n = 11). C. sakazakii CC4 is a clonal lineage strongly associated with neonatal meningitis. In the process of manufacturing PIF, the spray-drying, fluidized-bed-drying, and packing areas were the main areas with Cronobacter contamination. C. sakazakii strains with the same pulsotypes (PT3 and PT2) and sequence types (ST1 and ST64) were isolated both from processing equipment and from the PIF finished product.


Assuntos
Cronobacter/classificação , Cronobacter/isolamento & purificação , Microbiologia Ambiental , Fórmulas Infantis/microbiologia , Proteínas da Membrana Bacteriana Externa/genética , China , Análise por Conglomerados , Cronobacter/genética , DNA Bacteriano/química , DNA Bacteriano/genética , RNA Polimerases Dirigidas por DNA/genética , Eletroforese em Gel de Campo Pulsado , Manipulação de Alimentos , Genótipo , Técnicas de Genotipagem , Humanos , Dados de Sequência Molecular , Tipagem de Sequências Multilocus , Antígenos O/genética , Reação em Cadeia da Polimerase , Homologia de Sequência
13.
Int J Syst Evol Microbiol ; 65(Pt 4): 1335-1341, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25667396

RESUMO

A re-evaluation of the taxonomic position of two strains, 1383(T) and 2249, isolated from poppy seeds and tea leaves, which had been identified as Siccibacter turicensis (formerly Cronobacter zurichensis ), was carried out. The analysis included phenotypic characterization, 16S rRNA gene sequencing, multilocus sequence analysis (MLSA) of five housekeeping genes (atpD, fusA, glnS, gyrB and infB; 2034 bp) and ribosomal MLSA (53 loci; 22 511 bp). 16S rRNA gene sequence analysis and MLSA showed that the strains formed an independent phylogenetic lineage, with Siccibacter turicensis LMG 23730(T) as the closest neighbour. Average nucleotide identity analysis and phenotypic analysis confirmed that these strains represent a novel species, for which the name Siccibacter colletis sp. nov. is proposed. The type strain is 1383(T) ( = NCTC 14934(T) = CECT 8567(T) = LMG 28204(T)). An emended description of Siccibacter turicensis is also provided.


Assuntos
Camellia sinensis/microbiologia , Enterobacteriaceae/classificação , Papaver/microbiologia , Filogenia , Técnicas de Tipagem Bacteriana , DNA Bacteriano/genética , Enterobacteriaceae/genética , Enterobacteriaceae/isolamento & purificação , Genes Bacterianos , Dados de Sequência Molecular , Tipagem de Sequências Multilocus , Hibridização de Ácido Nucleico , Folhas de Planta/microbiologia , RNA Ribossômico 16S/genética , Sementes/microbiologia , Análise de Sequência de DNA
14.
Adv Exp Med Biol ; 830: 113-21, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25366224

RESUMO

Neonates in intensive care units often require supporting medical devices and antibiotic treatment. The intensive care treatment combined with their immature immune system, the increased permeability of mucosa, and the undeveloped microflora of the gut may render the neonates highly vulnerable to colonisation and subsequent infections when exposed to opportunistic pathogens. These infections may not only be local gastrointestinal infections, but also systematic following translocation from the gastrointestinal system. This could be particularly alarming considering that common antibiotics may not be effective if the causative strain is multi-drug resistant.This chapter reviews our information on the microbial colonization of neonatal feeding tubes. The range of organisms which have been recovered are wide, and while primarily bacterial, fungi such as Candida have also been found. The bacteria are principally Staphylococcus spp. and Enterobacteriaceae. The Enterobacteriaceae isolates are predominantly Enterobacter cancerogenus, Serratia marcescens, Enterobacter hormaechei, Escherichia coli and Klebsiella pneumoniae. Many of these isolates encode for antibiotic resistance; E. hormaechei (ceftazidine and cefotaxime) and S. marcescens strains (amoxicillin and co-amoxiclav).


Assuntos
Infecções Bacterianas/microbiologia , Biofilmes/crescimento & desenvolvimento , Nutrição Enteral/instrumentação , Consórcios Microbianos/fisiologia , Micoses/microbiologia , Infecções Bacterianas/etiologia , Infecções Bacterianas/prevenção & controle , Nutrição Enteral/efeitos adversos , Contaminação de Equipamentos/prevenção & controle , Contaminação de Alimentos/prevenção & controle , Humanos , Fórmulas Infantis/administração & dosagem , Recém-Nascido , Micoses/etiologia , Micoses/prevenção & controle
15.
BMC Genomics ; 15: 1121, 2014 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-25515150

RESUMO

BACKGROUND: Following the association of Cronobacter spp. to several publicized fatal outbreaks in neonatal intensive care units of meningitis and necrotising enterocolitis, the World Health Organization (WHO) in 2004 requested the establishment of a molecular typing scheme to enable the international control of the organism. This paper presents the application of Next Generation Sequencing (NGS) to Cronobacter which has led to the establishment of the Cronobacter PubMLST genome and sequence definition database (http://pubmlst.org/cronobacter/) containing over 1000 isolates with metadata along with the recognition of specific clonal lineages linked to neonatal meningitis and adult infections RESULTS: Whole genome sequencing and multilocus sequence typing (MLST) has supports the formal recognition of the genus Cronobacter composed of seven species to replace the former single species Enterobacter sakazakii. Applying the 7-loci MLST scheme to 1007 strains revealed 298 definable sequence types, yet only C. sakazakii clonal complex 4 (CC4) was principally associated with neonatal meningitis. This clonal lineage has been confirmed using ribosomal-MLST (51-loci) and whole genome-MLST (1865 loci) to analyse 107 whole genomes via the Cronobacter PubMLST database. This database has enabled the retrospective analysis of historic cases and outbreaks following re-identification of those strains. CONCLUSIONS: The Cronobacter PubMLST database offers a central, open access, reliable sequence-based repository for researchers. It has the capacity to create new analysis schemes 'on the fly', and to integrate metadata (source, geographic distribution, clinical presentation). It is also expandable and adaptable to changes in taxonomy, and able to support the development of reliable detection methods of use to industry and regulatory authorities. Therefore it meets the WHO (2004) request for the establishment of a typing scheme for this emergent bacterial pathogen. Whole genome sequencing has additionally shown a range of potential virulence and environmental fitness traits which may account for the association of C. sakazakii CC4 pathogenicity, and propensity for neonatal CNS.


Assuntos
Cronobacter/genética , Genoma Bacteriano , Tipagem de Sequências Multilocus , Algoritmos , Cronobacter/classificação , Cronobacter sakazakii/classificação , Cronobacter sakazakii/genética , Bases de Dados Genéticas , Ligação Genética , Loci Gênicos , Genótipo , Sequenciamento de Nucleotídeos em Larga Escala , Filogenia , Análise de Sequência de DNA
16.
Appl Environ Microbiol ; 79(16): 4951-7, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23770897

RESUMO

The genus Arcobacter is composed of 17 species which have been isolated from various sources. Of particular interest are A. butzleri, A. cryaerophilus, and A. skirrowii, as these have been associated with human cases of diarrhea, the probable transmission routes being through the ingestion of contaminated drinking water and food. To date, only limited studies of virulence traits in this genus have been undertaken. The present study used 60 Arcobacter strains isolated from different sources, representing 16 of the 17 species of the genus, to investigate their ability to adhere to and invade the human intestinal cell line Caco-2. In addition, the presence of five putative virulence genes (ciaB, cadF, cj1349, hecA, and irgA) was screened for in these strains by PCR. All Arcobacter species except A. bivalviorum and Arcobacter sp. strain W63 adhered to Caco-2 cells, and most species (10/16) were invasive. The most invasive species were A. skirrowii, A. cryaerophilus, A. butzleri, and A. defluvii. All invasive strains were positive for ciaB (encoding a putative invasion protein). Other putative virulence genes were present in other species, i.e., A. butzleri (cadF, cj1349, irgA, and hecA), A. trophiarum (cj1349), A. ellisii (cj1349), and A. defluvii (irgA). No virulence genes were detected in strains which showed little or no invasion of Caco-2 cells. These results indicate that many Arcobacter species are potential pathogens of humans and animals.


Assuntos
Arcobacter/genética , Arcobacter/patogenicidade , Aderência Bacteriana , Proteínas de Bactérias/genética , Arcobacter/classificação , Arcobacter/fisiologia , Proteínas de Bactérias/metabolismo , Células CACO-2 , Humanos , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Análise de Sequência de DNA , Especificidade da Espécie , Virulência
17.
Mol Cell Probes ; 27(3-4): 137-9, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23474194

RESUMO

The accuracy of the Cronobacter biotyping scheme was compared with the 7-loci multilocus sequence typing scheme. Biotyping did not reliably assign species level identification, as only half (17/31) of the biotype variants were unique to any of the seven Cronobacter species and the remaining biotypes were shared across the genus.


Assuntos
Cronobacter/classificação , Cronobacter/genética , Tipagem de Sequências Multilocus/métodos , DNA Bacteriano/química , Variação Genética , Especificidade da Espécie
18.
Mol Cell Probes ; 27(1): 60-4, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23089182

RESUMO

Cronobacter spp. (formerly Enterobacter sakazakii) can be isolated from a wide range of foods and environments, and its association with neonatal infections has drawn considerable attention from regulatory authorities. The principle route of neonatal infection has been identified as the ingestion of contaminated infant formula. A number of methods have been developed to identify Cronobacter spp., however these were before the most recent (2012) taxonomic revision of the genus into seven species. In this study, phenotyping, protein profiling and molecular methods were used to identify Cronobacter strains which had been recently isolated from ingredients used in the preparation of infant formula. Pulsed field gel electrophoresis revealed that different Cronobacter strains had been recovered from the same food products. All isolates were identified as Cronobacter sakazakii according to four genus specific PCR-probes and protein profiling using MALDI-TOF analysis. However, 16S rDNA sequence analyses and fusA allele sequencing gave more accurate identification: four strains were C. sakazakii, one strain was Cronobacter malonaticus and the remaining strain was Cronobacter universalis. Multilocus sequence typing showed the strains were different sequence types. These results demonstrate the presence of different Cronobacter species in food ingredients used in the preparation of infant formula, and also the need for molecular identification and profiling methods to be revised according to taxonomic revisions.


Assuntos
Cronobacter/classificação , Cronobacter/genética , Contaminação de Alimentos , Microbiologia de Alimentos , Fórmulas Infantis , Técnicas de Tipagem Bacteriana , Sequência de Bases , Cronobacter/isolamento & purificação , DNA Bacteriano/genética , Genótipo , Humanos , Lactente , Fator G para Elongação de Peptídeos/genética , Fenótipo , Análise Serial de Proteínas , RNA Ribossômico 16S/análise , Análise de Sequência de DNA , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
19.
Int J Syst Evol Microbiol ; 62(Pt 6): 1277-1283, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22661070

RESUMO

A re-evaluation of the taxonomic position of five strains, one assigned to Cronobacter sakazakii (strain 1330(T), isolated from spiced meat purchased in Slovakia), two previously assigned to Cronobacter genomospecies 1 (strains NCTC 9529(T) and 731, isolated from water and a leg infection, respectively) and two previously assigned to Cronobacter turicensis (strains 96 and 1435, isolated from onion powder and rye flour, respectively) was carried out. The analysis included phenotypic characterization, 16S rRNA gene sequencing and multilocus sequence analysis (MLSA) of seven housekeeping genes (atpD, fusA, glnS, gltB, gyrB, infB, ppsA; 3036 bp). 16S rRNA gene sequence analysis and MLSA showed that strain 1330(T) formed an independent phylogenetic lineage in the MLSA, with Cronobacter dublinensis LMG 23823(T) as the closest neighbour. DNA-DNA reassociation and phenotypic analysis revealed that strain 1330(T) represented a novel species, for which the name Cronobacter condimenti sp. nov. is proposed (type strain 1330(T) = CECT 7863(T) = LMG 26250(T)). Strains NCTC 9529(T), 731, 96 and 1435 clustered together within an independent phylogenetic lineage, with C. turicensis LMG 23827(T) as the closest neighbour in the MLSA. DNA-DNA reassociation and phenotypic analysis confirmed that these strains represent a novel species, for which the name Cronobacter universalis sp. nov. is proposed (type strain NCTC 9529(T) = CECT 7864(T) = LMG 26249(T)).


Assuntos
Cronobacter/classificação , Cronobacter/isolamento & purificação , Infecções por Enterobacteriaceae/microbiologia , Microbiologia de Alimentos , Perna (Membro)/microbiologia , Produtos da Carne/microbiologia , Microbiologia da Água , Criança , Cronobacter/genética , DNA Bacteriano/genética , Humanos , Masculino , Dados de Sequência Molecular , Filogenia , RNA Ribossômico 16S/genética , Eslováquia
20.
Emerg Infect Dis ; 17(9): 1713-5, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21888801

RESUMO

A 7-loci (3,036 nt) multilocus sequence typing scheme was applied to 41 clinical isolates of Cronobacter sakazakii. Half (20/41) of the C. sakazakii strains were sequence type (ST) 4, and 9/12 meningitis isolates were ST4. C. sakazakii ST4 appears to be a highly stable clone with a high propensity for neonatal meningitis.


Assuntos
Cronobacter sakazakii/genética , Infecções por Enterobacteriaceae/microbiologia , Meningites Bacterianas/microbiologia , Proteínas de Bactérias/genética , Cronobacter sakazakii/isolamento & purificação , Humanos , Recém-Nascido , Tipagem de Sequências Multilocus
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