Sanitary importance of arcobacter

The genus Arcobacter, belongs to the family Campylobacteraceae, along with. Some species, are considered emerging pathogens and have been associated with gastrointestinal diseases and bacteraemia in humans and with diarrhoea, mastitis and abortions in animals. Diarrhoea, is the most common clinical presentation in humans. However, still are not fully defined the routes of transmission, the virulence factors present in pathogenic strains have not been determined and the isolation and identification methods are still deficient. All of these factors contribute to a possible underestimation of the sanitary importance of this genus. In this thesis it has been demonstrated the existence of five new species of this genus. In their differentiation, new tools have been used, such as the Matrix Assisted Laser Desorption Ionization Time of Flight (MALDI TOF) Multilocus Phylogenetic Analysis (MLPA) with concatenated 5 genes (rpoB, gyrB, hsp60, gyrA and atpA). Furthermore, the performance of 5 molecular identification methods was compared and none of them was useful for all the strains studied. In this regard, the updating of 16S rRNARFLP method for the identification of all species proved very useful. Moreover, in this thesis was a great diversity of species of this genus in samples of shellfish and sewage. Both matrices have epidemiological importance; however, they have been poorly studied. It was also demonstrated that the use in parallel of direct culturing and post enrichment, as well as the incubation under aerobic and microaerophilic, enhances the recovery and diversity of arcobacters. Regarding the virulence of Arcobacter spp., most of them proved to be potential enteropathogens for man, as they showed the presence of virulence factors and were able to adhere and invade human intestinal cells (Caco-2). Finally, it was demonstrated that Arcobacter may be confused with Campylobacter sp., generating an underestimation of their sanitary importance.El género Arcobacter incluye especies consideradas patógenos emergentes, ya que se han asociado con patologías gastrointestinales y bacteriemia en humanos y con diarrea, mastitis y abortos en animales. Sin embargo, aún no se ha definido completamente las rutas de transmisión, los factores de virulencia presentes en cepas patogénicas no se han determinado y los métodos de aislamiento e identificación aún son deficientes. Todo esto genera una subestimación de la importancia sanitaria de Arcobacter. En esta tesis doctoral se demostró la existencia de 5 nuevas especies de este género. Para su diferenciación se utilizó herramientas nuevas, tales como el Matrix Assisted Laser desorption Ionization Time of Flight (MALDI TOF) y un Multilocus Phylogenetic Analysis (MLPA) con 5 genes concatenados (rpoB, gyrB, hsp60, atpA y gyrA). Considerando el número de especies incluidas actualmente en el género (n=17), se evaluó si 5 de los métodos moleculares de identificación son todavía útiles para la identificación de las especies para las que se habían definido o si se generan confusiones, demostrrando que todos ellos generan algún error que osciló entre el 16,8% y 67,4% de las cepas estudiadas. En este sentido, la ampliación del método 16S rRNA-RFLP para poder identificar todas las especies resultó ser de gran utilidad. Por otra parte, en esta tesis se observó una gran diversidad de especies de este género en muestras de mariscos y aguas residuales. Ambas matrices han sido poco estudiados a pesar de su importancia epidemiológica. Más aún, se demostró que el uso en paralelo del cultivo por siembra directa y post enriquecimiento, además de incubación en aerobiosis y microaerofilia, favorece la recuperación de una mayor diversidad. Por otra parte, también se demostró que la mayoría de las especies de este género, en especial algunas cepas A. butzleri, A. cryaerophilus, A. skirrowii, A. trophiarum y A. defluvii, son potenciales enteropatógenos para el hombre, ya que presentaron factores de virulencia y fueron capaces de adherir e invadir células intestinales humanas (Caco-2). Por último, se demostró que Arcobacter puede ser confundido con Campylobacter sp., lo que puede contribuir aún más a subestimar su importancia sanitaria

Adherence to and Invasion of Human Intestinal Cells by Arcobacter Species and Their Virulence Genotypes

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 transmissionrroutes 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

SIDEROPHORES FOR SELECTIVE SOLID PHASE EXTRACTION OF STRATEGIC ELEMENTS

All over the world, industrial mining is leaving contaminated areas and dumps that, although being full of valuable metals, have high concentrations of toxic heavy metals that pollute the environment. The development of sustainable alternative biomining and bioremediation processes offers the potential to fully exploit these unexploited mining sites

Cronobacter condimenti sp. nov., isolated from spiced meat, and Cronobacter universalis sp. nov., a species designation for Cronobacter sp. genomospecies 1, recovered from a leg infection, water, and food ingredients

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

Head-to-head comparison of CAMPYAIR aerobic culture medium versus standard microaerophilic culture for Campylobacter isolation from clinical samples

Campylobacter spp. are considered the most frequent cause of acute gastroenteritis worldwide. However, outside high-income countries, its burden is poorly understood. Limited published data suggest that Campylobacter prevalence in low- and middle-income countries is high, but their reservoirs and age distribution are different. Culturing Campylobacter is expensive due to laboratory equipment and supplies needed to grow the bacterium (e.g., selective culture media, microaerophilic atmosphere, and a 42°C incubator). These requirements limit the diagnostic capacity of clinical laboratories in many resource-poor regions, leading to significant underdiagnosis and underreporting of isolation of the pathogen. CAMPYAIR, a newly developed selective differential medium, permits Campylobacter isolation without the need for microaerophilic incubation. The medium is supplemented with antibiotics to allow Campylobacter isolation in complex matrices such as human feces. The present study aims to evaluate the ability of the medium to recover Campylobacter from routine clinical samples. A total of 191 human stool samples were used to compare the ability of CAMPYAIR (aerobic incubation) and a commercial Campylobacter medium (CASA, microaerophilic incubation) to recover Campylobacter. All Campylobacter isolates were then identified by MALDI-TOF MS. CAMPYAIR showed sensitivity and specificity values of 87.5% (95% CI 47.4%–99.7%) and 100% (95% CI 98%–100%), respectively. The positive predictive value of CAMPYAIR was 100% and its negative predictive value was 99.5% (95% CI 96.7%–99.9%); Kappa Cohen coefficient was 0.93 (95% CI 0.79–1.0). The high diagnostic performance and low technical requirements of the CAMPYAIR medium could permit Campylobacter culture in countries with limited resources

A household case evidences shorter shedding of SARS-CoV-2 in naturally infected cats compared to their human owners

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been detected in domestic and wild cats. However, little is known about natural viral infections of domestic cats, although their importance for modelling disease spread, informing strategies for managing positive human-animal relationships and disease prevention. Here, we describe the SARS-CoV-2 infection in a household of two human adults and sibling cats (one male and two females) using real-time RT-PCR, an ELISA test, viral sequencing, and virus isolation. On May 5th, 2020, the cat-owners tested positive for SARS-CoV-2. Two days later, the male cat showed mild respiratory symptoms and tested positive. Four days after the male cat, the two female cats became positive, asymptomatically. Also, one human and one cat showed antibodies against SARS-CoV-2. All cats excreted detectable SARS-CoV-2 RNA for a shorter duration than humans and viral sequences analysis confirmed human-to-cat transmission. We could not determine if cat-to-cat transmission also occurred

Acidithiobacillus thiooxidans secretome containing a newly described lipoprotein Licanantase enhances chalcopyrite bioleaching rate

The nature of the mineral–bacteria interphase where electron and mass transfer processes occur is a key element of the bioleaching processes of sulfide minerals. This interphase is composed of proteins, metabolites, and other compounds embedded in extracellular polymeric substances mainly consisting of sugars and lipids (Gehrke et al., Appl Environ Microbiol 64(7):2743–2747, 1998). On this respect, despite Acidithiobacilli—a ubiquitous bacterial genera in bioleaching processes (Rawlings, Microb Cell Fact 4(1):13, 2005)—has long been recognized as secreting bacteria (Jones and Starkey, J Bacteriol 82:788–789, 1961; Schaeffer and Umbreit, J Bacteriol 85:492–493, 1963), few studies have been carried out in order to clarify the nature and the role of the secreted protein component: the secretome. This work characterizes for the first time the sulfur (meta)secretome of Acidithiobacillus thiooxidans strain DSM 17318 in pure and mixed cultures with Acidithiobacillus ferrooxidans DSM 16786, identifying the major component of these secreted fractions as a single lipoprotein named here as Licanantase. Bioleaching assays with the addition of Licanantase-enriched concentrated secretome fractions show that this newly found lipoprotein as an active protein additive exerts an increasing effect on chalcopyrite bioleaching rate

First isolation report of Arcobacter cryaerophilus from a human diarrhea sample in Costa Rica

ABSTRACT Arcobacter cryaerophilus is an emerging enteropathogen and potential zoonotic agent transmitted by food and water. In Costa Rica, this bacterium has not been associated with cases of human gastroenteritis, even though it has been isolated from farm animals, especially poultry. This paper reports the first isolation of A. cryaerophilus from a human case of bloody watery diarrhea and the virulence genes associated with this isolate