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1.
Arch Microbiol ; 204(10): 610, 2022 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-36085198

RESUMO

Aliarcobacter butzleri (formerly known as Arcobacter butzleri) is an emerging food-borne zoonotic pathogen that establishes in vitro endosymbiotic relationships with Acanthamoeba castellanii, a free-living amoeba. Previously, we described that this bacterium acts as an endocytobiont of A. castellanii, surviving for at least 10 days in absence of bacterial replication. Thus, the aim of this study was to evaluate the ability of A. butzleri to survive as a long-term endosymbiont of A. castellanii for 30 days in two models of symbiotic interaction with A. castellanii: (i) endosymbiotic culture followed by gentamicin protection assay and (ii) transwell co-culture assay. The results allow us to conclude that A. butzleri is capable of surviving as an endosymbiont of A. castellanii for at least 30 days, without multiplying, under controlled laboratory conditions. In addition, in the absence of nutrients and as both microorganisms remain in the same culture, separated by semi-permeable membranes, A. castellanii does not promote the survival of A. butzleri, nor does it multiply. Our findings suggest that the greater survival capacity of A. butzleri is associated with their endosymbiont status inside A. castellanii, pointing out the complexity of this type of symbiotic relationship.


Assuntos
Acanthamoeba castellanii , Arcobacter , Acanthamoeba castellanii/microbiologia , Simbiose
2.
Molecules ; 27(14)2022 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-35889378

RESUMO

Extra-virgin olive oils contain many bioactive substances that are phenolic compounds. The survival of Arcobacter-like strains in non-buffered (WEOO) and buffered (BEOO) extracts of olive oils were studied. Time kill curves of different strains were measured in the environment of olive oil extracts of different grades. The activity of the extracts was also monitored for biofilm formation using the Christensen method. In vitro results revealed that extra-virgin olive oil extracts exhibited the strongest antimicrobial effects, especially non-buffered extracts, which exhibited strain inhibition after only 5 min of exposure. The weakest inhibitory effects were observed for olive oil extracts. A decrease in biofilm formation was observed in the environment of higher WEOO concentrations, although at lower concentrations of extracts, increased biofilm formation occurred due to stress conditions. The dialdehydic forms of oleuropein derivatives, hydroxytyrosol, and tyrosol were the main compounds detected by HPLC-CoulArray. The results indicate that not all olive oils had a similar bactericidal effect, and that bioactivity primarily depended on the content of certain phenolic compounds.


Assuntos
Arcobacter , Biofilmes , Azeite de Oliva/análise , Fenóis/análise , Fenóis/farmacologia , Plâncton , Óleos Vegetais/farmacologia , Água
3.
Microbiol Spectr ; 10(4): e0100322, 2022 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-35862990

RESUMO

Aliarcobacter butzleri is an emerging gastrointestinal pathogen found in many countries worldwide. In France, it has become the third most commonly isolated bacterial species from the stools of patients with intestinal infections. No interpretative criteria for antimicrobial susceptibility testing have been proposed for A. butzleri, and most strains are categorized using the recommendations of the Clinical and Laboratory Standards Institute or the European Committee on Antimicrobial Susceptibility Testing for Campylobacter or Enterobacterales. In the present study, the genomes of 30 resistant A. butzleri isolates were analyzed to propose specific epidemiological cut-off values for ampicillin, ciprofloxacin, erythromycin, and tetracycline. The identification of a ß-lactamase and the T85I GyrA mutation associated with ampicillin and ciprofloxacin resistance, respectively, allowed us to adjust the disk diffusion (DD) and MIC cut-off values for these molecules. However, epidemiological cut-off values for erythromycin and tetracycline could not be estimated due to the absence of known resistance mechanisms. The present study paves the way for building a consensus for antimicrobial susceptibility testing for this concerning pathogen. IMPORTANCE Aliarcobacter butzleri is an emerging and concerning intestinal pathogen. Very few studies have focused on this particular species, and antimicrobial susceptibility testing (AST) is based on methods that have been mostly developed for Campylobacter spp. In fact, no disk diffusion and E-tests adapted cut-offs for A. butzleri are available which leads to misinterpretations. We have shown here that NGS approach to identify genes and mutations in close relation to phenotypic resistance levels is a robust way to solve that issue and precisely differentiate WT and NWT A. butzleri isolates for frequently used antimicrobials. MIC and DD cut-off values have been significantly adjusted and answer the need for a global consensus regarding AST for A. butzleri.


Assuntos
Arcobacter , Ampicilina , Antibacterianos/farmacologia , Arcobacter/genética , Ciprofloxacina , Farmacorresistência Bacteriana/genética , Eritromicina , Humanos , Testes de Sensibilidade Microbiana , Tetraciclina/farmacologia
5.
BMC Genomics ; 23(1): 471, 2022 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-35761183

RESUMO

BACKGROUND: Emerging pathogenic bacteria are an increasing threat to public health. Two recently described species of the genus Aliarcobacter, A. faecis and A. lanthieri, isolated from human or livestock feces, are closely related to Aliarcobacter zoonotic pathogens (A. cryaerophilus, A. skirrowii, and A. butzleri). In this study, comparative genomics analysis was carried out to examine the virulence-related, including virulence, antibiotic, and toxin (VAT) factors in the reference strains of A. faecis and A. lanthieri that may enable them to become potentially opportunistic zoonotic pathogens. RESULTS: Our results showed that the genomes of the reference strains of both species have flagella genes (flaA, flaB, flgG, flhA, flhB, fliI, fliP, motA and cheY1) as motility and export apparatus, as well as genes encoding the Twin-arginine translocation (Tat) (tatA, tatB and tatC), type II (pulE and pulF) and III (fliF, fliN and ylqH) secretory pathways, allowing them to secrete proteins into the periplasm and host cells. Invasion and immune evasion genes (ciaB, iamA, mviN, pldA, irgA and fur2) are found in both species, while adherence genes (cadF and cj1349) are only found in A. lanthieri. Acid (clpB), heat (clpA and clpB), osmotic (mviN), and low-iron (irgA and fur2) stress resistance genes were observed in both species, although urease genes were not found in them. In addition, arcB, gyrA and gyrB were found in both species, mutations of which may mediate the resistance to quaternary ammonium compounds (QACs). Furthermore, 11 VAT genes including six virulence (cadF, ciaB, irgA, mviN, pldA, and tlyA), two antibiotic resistance [tet(O) and tet(W)] and three cytolethal distending toxin (cdtA, cdtB, and cdtC) genes were validated with the PCR assays. A. lanthieri tested positive for all 11 VAT genes. By contrast, A. faecis showed positive for ten genes except for cdtB because no PCR assay for this gene was available for this species. CONCLUSIONS: The identification of the virulence, antibiotic-resistance, and toxin genes in the genomes of A. faecis and A. lanthieri reference strains through comparative genomics analysis and PCR assays highlighted the potential zoonotic pathogenicity of these two species. However, it is necessary to extend this study to include more clinical and environmental strains to explore inter-species and strain-level genetic variations in virulence-related genes and assess their potential to be opportunistic pathogens for animals and humans.


Assuntos
Antibacterianos , Fatores de Virulência , Animais , Arcobacter , Campylobacteraceae , Genômica , Virulência/genética , Fatores de Virulência/genética , Fatores de Virulência/metabolismo
6.
World J Microbiol Biotechnol ; 38(8): 132, 2022 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-35689134

RESUMO

This study was aimed at the isolation and identification of Arcobacter spp. and Campylobacter spp. from fresh vegetables sold at district markets in the Kayseri province, and at the determination of the antibacterial susceptibility of the recovered isolates. For this purpose, a total of 175 vegetable samples, including 35 spinach, 35 lettuce, 35 parsley, 35 arugula, and 35 radish samples, were collected. While the pre-enrichment and membrane filtration techniques were used for the isolation of Arcobacter spp., the pre-enrichment and direct inoculation methods were used for the isolation of Campylobacter spp. The isolates were identified by means of phenotypic tests and the polymerase chain reaction (PCR), using genus- and species-specific primers. In addition, the susceptibilities of the isolates to amoxicillin-clavulanic acid, enrofloxacin, erythromycin, gentamicin, neomycin, streptomycin, and tetracycline were determined by the disk diffusion method. Out of the 175 vegetable samples tested, 93 (53.14%) were found to be positive for Arcobacter spp., and 119 Arcobacter spp. isolates were recovered from these 93 positive samples. All of the samples examined were found to be negative for Campylobacter spp. One hundred one (86%) and 14 (10%) of the 119 Arcobacter isolates obtained were identified as A. butzleri and A. cryaerophilus, respectively, but four isolates could not be identified at the species level by mPCR. Mixed contamination with more than one species and/or genotypes of Arcobacter was detected in 24 of the positive samples. While all of the Arcobacter isolates were susceptible to erythromycin, gentamicin, streptomycin, and tetracycline, 2 (1.68%), 2 (1.68%), and 5 (4.20%) isolates were resistant to amoxicillin/clavulanic acid, enrofloxacin, and neomycin, respectively. Consequently, the determination of a high prevalence of arcobacters and mixed contamination with more than one species and/or genotypes of arcobacters in vegetables often consumed raw by humans demonstrated that the consumption of raw vegetables may be a risk to the public health.


Assuntos
Arcobacter , Campylobacter , Antibacterianos/farmacologia , Arcobacter/genética , Campylobacter/genética , Enrofloxacina , Eritromicina/farmacologia , Microbiologia de Alimentos , Gentamicinas , Humanos , Neomicina , Prevalência , Estreptomicina , Tetraciclinas , Verduras
7.
Vet Microbiol ; 270: 109462, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35640411

RESUMO

Campylobacteriosis is a significant public health concern with Campylobacter jejuni and Campylobacter coli as main causative agents. Moreover, there is an increasing recognition of other pathogenic Campylobacter species and Campylobacter-like organisms as Arcobacter. However, current knowledge on presence of Arcobacter species in wild boars (Sus scrofa) is lacking, and knowledge on Campylobacter species is based on methods favoring growth of thermotolerant species. In this study, fecal samples originating from 76 wild boars hunted in Campania region (Italy) were examined for the presence of Campylobacter(-like) organisms by a culture dependent approach. Three isolation protocols were performed in parallel: Arcobacter-selective agar plates, mCCDA plates and isolation by passive filtration onto non-selective blood agar plates were used as quantitative isolation methods. Enrichment broths, i.e. Arcobacter selective enrichment broth, Preston broth and CAT broth were used for qualitative detection of low levels or stressed Campylobacter(-like) organisms. The Arcobacter and Campylobacter isolates were identified at species level using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and 16S ribosomal RNA (rRNA) sequence analysis. Overall, 41 (53.9%) of the animals excreted Arcobacter or Campylobacter while 38 (50.0%) shed Campylobacter and 8 (10.5%) Arcobacter. Campylobacter lanienae predominated and was isolated from 31 (40.8%) animals. No statistical difference between the age groups or gender with regard to the fecal excretion of Campylobacter(-like) organisms was observed. Thirty animals (39.5%) shed Campylobacter spp. exceeding levels of 10 ³ CFU g-1 feces. As samples were obtained from hunted wild boars intended for consumption, a potential contamination of meat with these bacterial pathogens must be considered.


Assuntos
Arcobacter , Infecções por Campylobacter , Campylobacter , Doenças dos Suínos , Ágar , Animais , Arcobacter/genética , Campylobacter/genética , Infecções por Campylobacter/microbiologia , Infecções por Campylobacter/veterinária , Sus scrofa , Suínos
8.
Int J Food Microbiol ; 373: 109712, 2022 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-35567892

RESUMO

Various species of the genus Arcobacter are regarded as emerging food pathogens and can be cause of human gastroenteric illness, among others. In order to gain knowledge on the risk associated with the presence of arcobacters in retail foods, this study aimed to determine their presence in a variety of products; to evaluate the genetic diversity and the occurrence of virulence and biofilm-associated genes in the isolated strains; and to assess their biofilm activity on polystyrene, borosilicate and stainless steel. Arcobacters were detected in the 22.3% of the analysed samples and the 83 recovered isolates were identified as A. butzleri (n = 53), A. cryaerophilus (n = 24), A. skirrowii (n = 2), A. thereius (n = 3) and A. vitoriensis (n = 1). They were isolated from virtually all tested food types, but mostly from squids and turkey meat (contamination levels of 60% and 40%, respectively). MLST differentiated 68 STs, most of which were novel (89.7%) and represented by a single strain (86.9%). Five novel STs were detected in various isolates derived from seafood, and the statistical analysis revealed their potential association with that type of food product (p < 0,001). All the isolates except one harboured virulence-associated genes and the highest incidence was noted for A. butzleri. Nineteen isolates (23.5%) were able to form biofilms on the different surfaces tested and, of note; glass enhanced the adhesion ability of the majority of them (84.2%). The results highlight the role that common food products can have in the transmission of Arcobacter spp., the pathogenic potential of the different species, and the survival and growth ability of several of them on different food contact surfaces. Therefore, the study provides interesting information regarding the risk arcobacters may pose to human health and the food industry.


Assuntos
Arcobacter , Biofilmes , Microbiologia de Alimentos , Humanos , Carne , Tipagem de Sequências Multilocus
9.
Water Res ; 217: 118397, 2022 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-35421690

RESUMO

Migratory geese could influence the microbiological water quality; however, their impacts on pathogen dynamics remain largely unknown. In this study, we analyzed the population dynamics of Campylobacter and Arcobacter group bacteria (AGB) in a freshwater lake in Japan over two years. The bacteria were quantified by using both culture-dependent and -independent methods. The potential sources of these bacteria were examined by a high-throughput flaA sequencing approach. Campylobacter was abundantly detected both by culture-dependent and -independent methods in the lake, especially when migratory geese were present in the lake. High-throughput flaA sequencing suggests that geese were the likely source of Campylobacter in the lake. The viable population of Campylobacter exceeds the concentrations that can potentially cause 10-4 infections per person per year when water is used to grow fresh vegetables. The occurrence of AGB, on the other hand, was not directly related to the population of migratory geese. AGB were not detected in geese fecal samples. Diverse AGB flaA genotypes occurred in the lake over multiple seasons. Our results suggest that AGB likely comprise a part of the indigenous microbial population of the lake and grow in response to high nutrient, warm temperature, and low dissolved oxygen concentrations in the lake. Geese therefore can indirectly impact the AGB population by providing nutrients to cause eutrophication and lower the dissolved oxygen concentration. Since geese travel long-distance and disperse their fecal microbiota and nutrients to wide areas, they may have significant impacts on water quality and public health.


Assuntos
Arcobacter , Campylobacter , Animais , Bactérias/genética , Campylobacter/genética , Gansos/microbiologia , Humanos , Lagos , Oxigênio
10.
Vet Med Sci ; 8(4): 1841-1849, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35426255

RESUMO

BACKGROUND: Arcobacter spp. has been considered an emerging foodborne pathogen and a hazard to human health. The dairy chain has been isolated from different sources; nevertheless, data on Arcobacter occurrence in raw milk and dairy products in Iran are still scant. OBJECTIVE: The present study investigates the prevalence, antimicrobial susceptibility and the presence of virulence genes of Arcobacters species isolated from milk and dairy products. METHODS: Then, a total of 350 raw milk samples and 400 dairy product samples were collected from dairy supply centers in Isfahan, Iran. Presumptive Arcobacter strains were obtained by enriching samples in Oxoid Arcobacter enrichment broth (AEB) followed by the filtration of enrichment product through 0.45-µm pore size membrane filters laid onto non-selective blood at 30°C under microaerophilic conditions. Molecular identification of Arcobacter cryaerophilus and A. butzleri was performed by Polymerase chain reaction (PCR) amplification of the 16S rRNA gene, followed by sequencing. The disc diffusion method was used to determine the antimicrobial susceptibility of isolates. Targeted resistance and virulence genes were detected using multiplex PCR. RESULTS: The results show a low recovery rate of Arcobacter spp. in milk. Arcobacters were found in all types of milk, except raw camel milk, but were absent from all dairy products. Arcobacter butzleri was the predominant species in raw milk. Detection of virulence genes shows that all virulence genes targeted were found among A. butzleri, and six (cadF, cj1349, irgA, mviN, pldA, tlyA) were found among A. cryaerophilus. All A. butzleri strains and some A. cryaerophilus strains isolated from milk were resistant to amoxicillin-clavulanic acid and tetracycline. All A. cryaerophilus isolates from milk were susceptible to gentamycin, streptomycin, erythromycin and ciprofloxacin. The distribution of resistance genes in Arcobacter strains in milk shows that all isolates carried tet(O) and blaOXA-61 genes. CONCLUSIONS: In conclusion, the results indicate a low recovery rate of Arcobacter spp. in milk and milk products. However, a significant number of Arcobacter strains with putative virulence genes may be potential pathogens for humans and an overall increase in Arcobacter resistance to first-line antibiotics. These results highlight the need for regular surveillance of Arcobacter strains in milk and milk products in Iran.


Assuntos
Arcobacter , Animais , Antibacterianos/farmacologia , Arcobacter/genética , Resistência Microbiana a Medicamentos , Genótipo , Humanos , Leite , Reação em Cadeia da Polimerase Multiplex/veterinária , Prevalência , RNA Ribossômico 16S , Fatores de Virulência/genética
11.
Int J Syst Evol Microbiol ; 71(11)2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34825881

RESUMO

This paper re-examines the taxonomic positions of recently described Poseidonibacter (P. parvum and P. antarcticus), Aliarcobacter ('Al. vitoriensis'), Halarcobacter ('H. arenosus') and Arcobacter (A. caeni, A. lacus) species, and other species proposed to represent novel genera highly related to the genus Arcobacter. Phylogenomic and several overall genome relatedness indices (OGRIs) were applied to a total of 118 representative genomes for this purpose. Phylogenomic analyses demonstrated the Arcobacter clade to be distinct from other Epsilonproteobacteria, clearly defined and containing closely related species. Aliarcobacter butzleri and Malaciobacter pacificus did not cluster with other members of these proposed genera, indicating incoherence of these genera. Every OGRI measure applied indicated a high level of relatedness among all Arcobacter clade species, including the recently described taxa studied here, and substantially lower between type species representatives for other Epsilonproteobacteria. Where published guidelines were available, OGRI values for Arcobacter clade species were either unsupportive of division into other genera or were at the lowest boundary range (for average amino acid identity). We propose that Aliarcobacter, Halarcobacter, Malaciobacter, Pseudarcobacter, Poseidonibacter and Arcobacter sensu stricto be considered members of a single genus, Arcobacter, and subsequently transfer P. parvum, P. antarcticus, 'Al. vitoriensis' and 'H. arenosus' to Arcobacter as Arcobacter parvum comb. nov., Arcobacter antarcticus comb. nov., Arcobacter vitoriensis comb. nov. and Arcobacter arenosus comb. nov.


Assuntos
Arcobacter , Filogenia , Arcobacter/classificação
12.
Int J Syst Evol Microbiol ; 71(11)2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34797211

RESUMO

A study on the polyphasic taxonomic classification of an Arcobacter strain, R-73987T, isolated from the rectal mucus of a porcine intestinal tract, was performed. Phylogenetic analysis based on the 16S rRNA gene sequence revealed that the strain could be assigned to the genus Arcobacter and suggested that strain R-73987T belongs to a novel undescribed species. Comparative analysis of the rpoB gene sequence confirmed the findings. Arcobacter faecis LMG 28519T was identified as its closest neighbour in a multigene analysis based on 107 protein- encoding genes. Further, whole-genome sequence comparisons by means of average nucleotide identity and in silico DNA-DNA hybridization between the genome of strain R-73987T and the genomes of validly named Arcobacter species resulted in values below 95-96 and 70  %, respectively. In addition, a phenotypic analysis further corroborated the conclusion that strain R-73987T represents a novel Arcobacter species, for which the name Arcobacter vandammei sp. nov. is proposed. The type strain is R-73987T (=LMG 31429T=CCUG 75005T). This appears to be the first Arcobacter species recovered from porcine intestinal mucus.


Assuntos
Arcobacter , Filogenia , Reto/microbiologia , Sus scrofa/microbiologia , Animais , Arcobacter/classificação , Arcobacter/isolamento & purificação , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Muco/microbiologia , Hibridização de Ácido Nucleico , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Suínos
13.
Infect Dis Now ; 51(6): 564-566, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34486524

RESUMO

The first case of acute watery diarrhea disease due to Aliarcobacter butzleri (formerly Arcobacter butzleri) in Ecuador is reported. An infant presented with moderate protein-calorie malnutrition, dehydration and anemia. A curved Gram-negative organism was isolated from stools, having been preliminarily identified by phenotypic characteristics. Definitive identification was achieved by multiplex PCR. Aliarcobacter butzleri was the only pathogenic microorganism isolated. No other entero-pathogens, enterovirus or parasites were found. Our findings strongly suggest that in this specific case, A. butzleri was the etiological agent. Further investigations are needed to develop standardized diagnostic protocols and to establish the prevalence and significance of Aliarcobacter infections in humans.


Assuntos
Arcobacter , Infecções por Bactérias Gram-Negativas , Diarreia/diagnóstico , Equador/epidemiologia , Fezes , Infecções por Bactérias Gram-Negativas/diagnóstico , Humanos , Lactente
14.
Microbiol Spectr ; 9(2): e0095521, 2021 10 31.
Artigo em Inglês | MEDLINE | ID: mdl-34468192

RESUMO

Conspicuous egg-shaped, white, and smooth structures were observed at a hydrothermal vent site in the Guaymas Basin, Gulf of California. The gelatinous structures decomposed within hours after sampling. Scanning electron microscopy (SEM) and light microscopy showed that the structure consisted of filaments of less than 0.1 µm thickness, similar to those observed for "Candidatus Arcobacter sulfidicus." SEM-energy-dispersive X-ray spectroscopy (EDS) showed that the filaments were sulfur rich. According to 16S rRNA gene amplicon and fluorescence in situ hybridization (FISH) analyses, Arcobacter, a sulfide oxidizer that is known to produce filamentous elemental sulfur, was among the dominant species in the structure and was likely responsible for its formation. Arcobacter normally produces woolly snowflake like structures in opposed gradients of sulfide and oxygen. In the laboratory, we observed sulfide consumption in the anoxic zone of the structure, suggesting an anaerobic conversion. The sulfide oxidation and decomposition of the structure in the laboratory may be explained by dissolution of the sulfur filaments by reaction with sulfide under formation of polysulfides. IMPORTANCE At the deep-sea Guaymas Basin hydrothermal vent system, sulfide-rich hydrothermal fluids mix with oxygenated seawater, thereby providing a habitat for microbial sulfur oxidation. Microbial sulfur oxidation in the deep sea involves a variety of organisms and processes and can result in the excretion of elemental sulfur. Here, we report on conspicuous white and smooth gelatinous structures found on hot vents. These strange egg-shaped structures were often observed on previous occasions in the Guaymas Basin, but their composition and formation process were unknown. Our data suggest that the notable and highly ephemeral structure was likely formed by the well-known sulfide-oxidizing Arcobacter. While normally Arcobacter produces loose flocs or woolly layers, here smooth gel-like structures were found.


Assuntos
Arcobacter/classificação , Arcobacter/metabolismo , Fontes Hidrotermais/microbiologia , Sulfetos/metabolismo , Enxofre/metabolismo , Anaerobiose/fisiologia , Arcobacter/genética , Hibridização in Situ Fluorescente , México , Oceanos e Mares , Oxirredução , RNA Ribossômico 16S/genética , Água do Mar/química
15.
Sci Total Environ ; 800: 149465, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34391144

RESUMO

The thermal spring of Fetida Cave, a still active sulfuric acid cave opening at sea level and located in Santa Cesarea Terme, southeastern Salento (Apulia region, Southern Italy) hosts abundant floating white filaments. The white filaments were mainly composed of sulfur crystals surrounded by microbial mass of the phyla Epsilonbacteraeota, Proteobacteria, Bacteroidetes, and Patescibacteria. The most abundant genus in the white filaments collected from the waters in the innermost part of the cave dominated by sulfidic exhalations was Arcobacter. This abundance can be related to the higher concentration of sulfide dissolved in water, and low oxygen and pH values. Conversely, lower Arcobacter abundances were obtained in the filaments collected in the entrance and middle part of the cave, where sulfidic water mixes with seawater, as the cave is subjected to tides and the mixing of fresh (continental) with marine water. The geochemical analysis of water and atmospheric gases confirmed these environmental constraints. In fact, the highest concentrations of H2S in the air and water were recorded closest to the spring upwelling in the innermost part of the cave, and the lowest ones near the cave entrance. The metabolic versatility of Arcobacter might provide a competitive advantage in the colonization of water bodies characterized by high sulfide, low oxygen, and dynamic fluid movement.


Assuntos
Arcobacter , Cavernas , Água do Mar , Sulfetos , Enxofre
16.
PLoS One ; 16(8): e0256305, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34411155

RESUMO

Andros Island, The Bahamas, composed of porous carbonate rock, has about 175 inland blue holes and over 50 known submerged ocean caves along its eastern barrier reef. These ocean blue holes can have both vertical and horizontal zones that penetrate under the island. Tidal forces drive water flow in and out of these caves. King Kong Cavern has a vertical collapse zone and a deep penetration under Andros Island that emits sulfidic, anoxic water and masses of thin, mucoid filaments ranging to meters in length and off-white turbid water during ebb flow. Our objective was to determine the microbial composition of this mucoid material and the unconsolidated water column turbidity based on the concept that they represent unique lithoautotrophic microbial material swept from the cave into the surrounding ocean. Bacterial DNA extracted from these filaments and surrounding turbid water was characterized using PCR that targeted a portion of the 16S rRNA gene. The genus Arcobacter dominated both the filaments and the water column above the cave entrance. Arcobacter nitrofigilis and Arcobacter sp. UDC415 in the mucoid filaments accounted for as much as 80% of mapped DNA reads. In the water column Arcobacter comprised from 65% to over 85% of the reads in the depth region from about 18 m to 34 m. Bacterial species diversity was much higher in surface water and in water deeper than 36 m than in the intermediate zone. Community composition indicates that ebb flow from the cavern influences the entire water column at least to within 6 m of the surface and perhaps the near surface as well.


Assuntos
Arcobacter/isolamento & purificação , Microbiota/genética , Filogenia , Água do Mar/microbiologia , Arcobacter/genética , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Bahamas , Cavernas/microbiologia , Oceanos e Mares , RNA Ribossômico 16S/genética , Microbiologia da Água
17.
J Water Health ; 19(4): 657-670, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34371501

RESUMO

The management of pathogenic bacteria in waterways is a public health issue. Here, we investigated the concentrations of potentially pathogenic bacteria, Arcobacter spp. and Campylobacter spp., and Escherichia coli, by quantifying species-specific genes in surface water samples from canals and the Chao Phraya River from June 2017 to June 2018 in Bangkok, Thailand. We assessed the relationship between the specific bacterial concentrations, water quality, and seasonal changes. Arcobacter spp. were detected at high density in all samples and showed seasonal fluctuations according to analyses based on 16S rDNA and the invasion gene ciaB. High levels of 16S rDNA and dut gene of E. coli were detected in the polluted drainage canals. A high correlation was observed between E. coli and chemical and biochemical oxygen demand (COD and BOD), suggesting that untreated domestic wastewater was the source of the E. coli. In contrast, Arcobacter spp. were detected with high density even in water samples with relatively low COD, suggesting that Arcobacter spp. are more likely than E. coli to survive in the water environment. The analysis of 16S rDNA and ciaB gene sequence analyses indicated that the Arcobacter spp. isolated from the drainage canals were A. butzleri and A. cryaerophilus.


Assuntos
Arcobacter , Arcobacter/genética , Escherichia coli/genética , Rios , Especificidade da Espécie , Tailândia
18.
Environ Pollut ; 288: 117673, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34218080

RESUMO

Mobile genetic elements (MGEs) such as plasmids or integrative conjugative elements (ICEs) are widely involved in the horizontal transfer of antibiotic resistant genes (ARGs), but their environmental host-range and reservoirs remain poorly known, as mainly assessed through the analysis of culturable and clinical bacterial isolates. In this study, we used a gradual approach for determining the environmental abundance and host-range of ICEs belonging to the SXT/R391 family, otherwise well known to bring ARGs in Vibrio spp. epidemic clones and other pathogens. First, by screening a set of aquatic bacteria libraries covering 1794 strains, we found that almost 1% of the isolates hosted an SXT/R391 element, all belonging to a narrow group of non-O1/non-O139 Vibrio cholerae. However, when SXT/R391 ICEs were then quantified in various aquatic communities, they appeared to be ubiquitous and relatively abundant, from 10-6 to 10-3 ICE copies per 16 S rDNA. Finally, the molecular exploration of the SXT/R391 host-range in two river ecosystems impacted by anthropogenic activities, using the single-cell genomic approach epicPCR, revealed several new SXT/R391 hosts mostly in the Proteobacteria phylum. Some, such as the pathogen Arcobacter cryaerophilus (Campylobacteraceae), have only been encountered in discharged treated wastewaters and downstream river waters, thus revealing a likely anthropogenic origin. Others, such as the non-pathogenic bacterium Neptunomonas acidivorans (Oceanospirillaceae), were solely identified in rivers waters upstream and downstream the treated wastewaters discharge points and may intrinsically belong to the SXT/R391 environmental reservoir. This work points out that not only the ICEs of the SXT/R391 family are more abundant in the environment than anticipated, but also that a variety of unsuspected hosts may well represent a missing link in the environmental dissemination of MGEs from and to bacteria of anthropogenic origin.


Assuntos
Conjugação Genética , Especificidade de Hospedeiro , Arcobacter , Ecossistema , Oceanospirillaceae
19.
Genomics ; 113(4): 2065-2076, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33961980

RESUMO

Aliarcobacter butzleri is an emerging pathogen that may cause enteritis in humans, however, the incidence of disease caused by this member of the Campylobacteriaceae family is still underestimated. Furthermore, little is known about the precise virulence mechanism and behavior during infection. Therefore, in the present study, through complementary use of comparative genomics and physiological tests on human gut models, we sought to elucidate the genetic background of a set of 32 A. butzleri strains of diverse origin and to explore the correlation with the ability to colonize and invade human intestinal cells in vitro. The simulated infection of human intestinal models showed a higher colonization rate in presence of mucus-producing cells. For some strains, human mucus significantly improved the resistance to physical removal from the in vitro mucosa, while short time-frame growth was even observed. Pangenome analysis highlighted a hypervariable accessory genome, not strictly correlated to the isolation source. Likewise, the strain phylogeny was unrelated to their shared origin, despite a certain degree of segregation was observed among strains isolated from different segments of the intestinal tract of pigs. The putative virulence genes detected in all strains were mostly encompassed in the accessory fraction of the pangenome. The LPS biosynthesis and in particular the chain glycosylation of the O-antigen is harbored in a region of high plasticity of the pangenome, which would indicate frequent horizontal gene transfer phenomena, as well as the involvement of this hypervariable structure in the adaptive behavior and sympatric evolution of A. butzleri. Results of the present study deepen the current knowledge on A. butzleri pangenome by extending the pool of genes regarded as virulence markers and provide bases to develop new diagnostic approaches for the detection of those strains with a higher virulence potential.


Assuntos
Arcobacter , Animais , Arcobacter/genética , Genoma Bacteriano , Genômica , Humanos , Muco , Filogenia , Suínos , Virulência/genética , Fatores de Virulência/genética
20.
PLoS One ; 16(4): e0250401, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33886647

RESUMO

The Rimac river is the main source of water for Lima, Peru's capital megacity. The river is constantly affected by different types of contamination including mine tailings in the Andes and urban sewage in the metropolitan area. In this work, we aim to produce the first characterization of aquatic bacterial communities in the Rimac river using a 16S rRNA metabarcoding approach which would be useful to identify bacterial diversity and potential understudied pathogens. We report a lower diversity in bacterial communities from the Lower Rimac (Metropolitan zone) in comparison to other sub-basins. Samples were generally grouped according to their geographical location. Bacterial classes Alphaproteobacteria, Bacteroidia, Campylobacteria, Fusobacteriia, and Gammaproteobacteria were the most frequent along the river. Arcobacter cryaerophilus (Campylobacteria) was the most frequent species in the Lower Rimac while Flavobacterium succinicans (Bacteroidia) and Hypnocyclicus (Fusobacteriia) were the most predominant in the Upper Rimac. Predicted metabolic functions in the microbiota include bacterial motility and quorum sensing. Additional metabolomic analyses showed the presence of some insecticides and herbicides in the Parac-Upper Rimac and Santa Eulalia-Parac sub-basins. The dominance in the Metropolitan area of Arcobacter cryaerophilus, an emergent pathogen associated with fecal contamination and antibiotic multiresistance, that is not usually reported in traditional microbiological quality assessments, highlights the necessity to apply next-generation sequencing tools to improve pathogen surveillance. We believe that our study will encourage the integration of omics sciences in Peru and its application on current environmental and public health issues.


Assuntos
Organismos Aquáticos/genética , Arcobacter/genética , Código de Barras de DNA Taxonômico/métodos , Flavobacterium/genética , Fusobactérias/genética , Microbiota/genética , RNA Ribossômico 16S/genética , Rios/microbiologia , Biologia Computacional/métodos , Monitoramento Ambiental/métodos , Peru , Esgotos/microbiologia , Água/análise , Microbiologia da Água , Poluição da Água/análise
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