RESUMEN
Alcaligenes faecalis is one of the most important and clinically significant environmental pathogens, increasing in importance due to its isolation from soil and nosocomial environments. The Gram-negative soil bacterium is associated with skin endocarditis, bacteremia, dysentery, meningitis, endophthalmitis, urinary tract infections, and pneumonia in patients. With emerging antibiotic resistance in A. faecalis, it has become crucial to understand the origin of such resistance genes within this clinically significant environmental and gut bacterium. In this research, we studied the impact of antibiotic overuse in poultry and its effect on developing resistance in A. faecalis. We sampled soil and faecal materials from five poultry farms, performed whole genome sequencing & analysis and identified four strains of A. faecalis. Furthermore, we characterized the genes in the genomic islands of A. faecalis isolates. We found four multidrug-resistant A. faecalis strains that showed resistance against vancomycin (MIC >1000 µg/ml), ceftazidime (50 µg/ml), colistin (50 µg/ml) and ciprofloxacin (50 µg/ml). From whole genome comparative analysis, we found more than 180 resistance genes compared to the reference sequence. Parts of our assembled contigs were found to be similar to different bacteria which included pbp1A and pbp2 imparting resistance to amoxicillin originally a part of Helicobacter and Bordetella pertussis. We also found the Mycobacterial insertion element IS6110 in the genomic islands of all four genomes. This prominent insertion element can be transferred and induce resistance to other bacterial genomes. The results thus are crucial in understanding the transfer of resistance genes in the environment and can help in developing regimes for antibiotic use in the food and poultry industry.
Asunto(s)
Antibacterianos , Farmacorresistencia Bacteriana Múltiple , Granjas , Aves de Corral , Microbiología del Suelo , Animales , Farmacorresistencia Bacteriana Múltiple/genética , Aves de Corral/microbiología , Antibacterianos/farmacología , Pruebas de Sensibilidad Microbiana , Variación Genética , Secuenciación Completa del Genoma , Islas Genómicas , Alcaligenes faecalis/genética , Alcaligenes faecalis/aislamiento & purificación , Alcaligenes faecalis/efectos de los fármacos , Genoma Bacteriano , Heces/microbiología , Infecciones por Bacterias Gramnegativas/microbiología , Infecciones por Bacterias Gramnegativas/veterinariaRESUMEN
BACKGROUND: Alcaligenes faecalis is usually causes opportunistic infections in humans. Alcaligenes faecalis infection is often difficult to treat due to its increased resistance to several antibiotics. The results from a clinical study of patients with Alcaligenes faecalis infection may help improve patients' clinical care. METHODS: We conducted a retrospective analysis of all patients presenting with Alcaligenes faecalis infection from January 2014 to December 2019. The medical records of all patients were reviewed for demographic information, clinical symptoms and signs, comorbidities, use of intravenous antibiotics within the past three months, bacterial culture, antibiotics sensitivity test, and clinical outcomes. RESULTS: Sixty-one cases of Alcaligenes faecalis infection were seen during the study period, including 25 cases of cystitis, nine cases of diabetic foot infection, eight cases of pneumonia, seven cases of acute pyelonephritis, three cases of bacteremia, and nine cases of infection at specific sites. Thirty-seven patients (60.7%) had a history of receiving intravenous antibiotics within three months of the diagnosis. Fifty-one (83.6%) cases were mixed with other bacterial infections. Extensively drug-resistant infections have been reported since 2018. The best sensitivity rate to Alcaligenes faecalis was 66.7% for three antibiotics (imipenem, meropenem, and ceftazidime) in 2019. Two antibiotics (ciprofloxacin and piperacillin/tazobactam) sensitivity rates to A. faecalis were less than 50%. CONCLUSIONS: The most frequent Alcaligenes faecalis infection sites, in order, are the bloodstream, urinary tract, skin and soft tissue, and middle ear. The susceptibility rate of Alcaligenes faecalis to commonly used antibiotics is decreasing. Extensively drug-resistant Alcaligenes faecalis infections have emerged.
Asunto(s)
Alcaligenes faecalis/efectos de los fármacos , Antibacterianos/uso terapéutico , Ceftazidima/uso terapéutico , Farmacorresistencia Bacteriana Múltiple/efectos de los fármacos , Infecciones por Bacterias Gramnegativas/tratamiento farmacológico , Imipenem/uso terapéutico , Meropenem/uso terapéutico , Adulto , Anciano , Anciano de 80 o más Años , Alcaligenes faecalis/genética , Alcaligenes faecalis/aislamiento & purificación , Bacteriemia/tratamiento farmacológico , Bacteriemia/microbiología , Femenino , Infecciones por Bacterias Gramnegativas/microbiología , Humanos , Masculino , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Estudios Retrospectivos , Resultado del TratamientoRESUMEN
Consumption of heavy metals, especially lead (Pb) contaminated food is a serious threat to human health. Higher Pb uptake by the plant affects the quality, growth and yield of crops. However, inoculation of plant growth-promoting rhizobacteria (PGPR) along with a mixture of organic amendments and biochar could be an effective way to overcome the problem of Pb toxicity. That's why current pot experiment was conducted to investigate the effect of compost mixed biochar (CB) and ACC deaminase producing PGPR on growth and yield of spinach plants under artificially induced Pb toxicity. Six different treatments i.e., control, Alcaligenes faecalis (PGPR1), Bacillus amyloliquefaciens (PGPR2), compost + biochar (CB), PGPR1 + CB and PGPR2 + CB were applied under 250 mg Pb kg-1 soil. Results showed that inoculation of PGPRs (Alcaligenes faecalis and Bacillus amyloliquefaciens) alone and along with CB significantly enhanced root fresh (47%) and dry weight (31%), potassium concentration (11%) in the spinach plant. Whereas, CB + Bacillus amyloliquefaciens significantly decreased (43%) the concentration of Pb in the spinach root over control. In conclusion, CB + Bacillus amyloliquefaciens has the potential to mitigate the Pb induced toxicity in the spinach. The obtained result can be further used in the planning and execution of rhizobacteria and compost mixed biochar-based soil amendment.
Asunto(s)
Carbón Orgánico/química , Plomo/toxicidad , Contaminantes del Suelo/toxicidad , Spinacia oleracea/efectos de los fármacos , Alcaligenes faecalis/enzimología , Alcaligenes faecalis/aislamiento & purificación , Alcaligenes faecalis/metabolismo , Bacillus amyloliquefaciens/enzimología , Bacillus amyloliquefaciens/aislamiento & purificación , Bacillus amyloliquefaciens/metabolismo , Proteínas Bacterianas/metabolismo , Liasas de Carbono-Carbono/metabolismo , Clorofila/metabolismo , Concentración de Iones de Hidrógeno , Plomo/química , Plomo/metabolismo , Raíces de Plantas/crecimiento & desarrollo , Raíces de Plantas/metabolismo , Raíces de Plantas/microbiología , Potasio/análisis , Suelo/química , Microbiología del Suelo , Contaminantes del Suelo/química , Contaminantes del Suelo/metabolismo , Spinacia oleracea/química , Spinacia oleracea/microbiología , SimbiosisRESUMEN
Colistin is a last-resort drug used to treat infections caused by multidrug-resistant Gram-negative bacteria that have developed carbapenem resistance. Emergence and rapid dissemination of the nine plasmid-mediated mobile colistin resistance genes (mcr-1 to mcr-9) has led to fear of pandrug-resistant infections worldwide. To date, there is only limited information on colistin resistance in African countries where the drug is widely used in agriculture. In this Nigerian study, 583 non-duplicate bacterial strains were isolated from 1119 samples from humans, camels, cattle, dogs, pigs and poultry using colistin-supplemented MacConkey agar, among which 17.0% (99/583) were colistin-resistant. PCR (mcr-1 to mcr-9) and whole-genome sequencing (WGS) identified mcr in 21.2% (21/99) of colistin-resistant isolates: mcr-1.1 (n = 13), mcr-8.1 (n = 5), mcr-1.1 and mcr-8.1 (n = 2), and mcr-1.1 and mcr-5 (n = 1). Of the 21 mcr-positive strains, 9 were isolated from human samples, with 8 being Klebsiella pneumoniae, and 6 of these human K. pneumoniae had a high colistin MIC (>64 µg/mL). In contrast, 9 of the 12 mcr-positive animal isolates were Escherichia coli, of which only 2 had a colistin MIC of >64 µg/mL. This study is the first to report mcr-1 in Alcaligenes faecalis and the emergence of mcr-5 and mcr-8 in Nigeria. WGS determined that mcr-1 was localised on an IncX4 plasmid and that 95.2% of mcr-1 harbouring isolates (20/21) transferred colistin resistance successfully by conjugation. These findings highlight the global spread of colistin resistance and emphasise the urgent need for co-ordinated global action to combat resistant bacteria.
Asunto(s)
Alcaligenes faecalis/genética , Antibacterianos/farmacología , Colistina/farmacología , Farmacorresistencia Bacteriana Múltiple/genética , Enterobacteriaceae/genética , Plásmidos/genética , Alcaligenes faecalis/efectos de los fármacos , Alcaligenes faecalis/aislamiento & purificación , Animales , Bovinos , Perros , Enterobacteriaceae/efectos de los fármacos , Enterobacteriaceae/aislamiento & purificación , Humanos , Pruebas de Sensibilidad Microbiana , Nigeria , Retroelementos/genética , PorcinosRESUMEN
Bacterial isolates Pseudomonas aeruginosa BR, Alcaligenes faecalis SW and Escherichia coli EC from a microbial fuel cell (MFC) were cocultured with each other. The isolates were added in a specific sequence one after the other (two cultures in one reactor). The study helped us conceptualise the synergistic and antagonistic behaviour of bacterial isolates and also emphasised the sequence in which a culture can be introduced in an anode chamber. The coculture conditions were evaluated on the basis of redox activity, electron transfer rate, columbic efficiency, and internal resistances. A good syntropy in terms of power production was found between P. aeruginosa BR and E. coli EC that recorded a power generation of 207.593 ± 1.705 µW/m2 . The addition of any culture in any sequence affected the performance of P. aeruginosa BR. This culture when added as a secondary culture in the reactor enhanced the performance of that reactor. The sequence of addition of a culture in a reactor affected the performance in the combinations of (a) P. aeruginosa BR and A. faecalis SW and (b) A. faecalis SW and E. coli EC.
Asunto(s)
Alcaligenes faecalis/metabolismo , Fuentes de Energía Bioeléctrica/microbiología , Reactores Biológicos/microbiología , Escherichia coli/metabolismo , Pseudomonas aeruginosa/metabolismo , Alcaligenes faecalis/aislamiento & purificación , Técnicas Electroquímicas/métodos , Escherichia coli/aislamiento & purificación , Pseudomonas aeruginosa/aislamiento & purificación , Energía RenovableRESUMEN
Coleus forskohlii is an herb, well-known for its medicinal compound forskolin present in its roots, with wide range of pharmaceutical applications. Here, we report, for the first time, the role of plant-probiotic bacterial endophytes of C. forskohlii, CFLB1 and CFRB1, isolated from leaf and root, which regulate plant growth and in plant forskolin content. Native bacterial endophyte, CFRB1 (Alcaligenes faecalis), significantly modulates primary plant productivity and forskolin content under pot and field conditions. Under field conditions, CFRB1 endophyte application significantly enhanced photosynthetic pigments and reduced the severity of root-knot and root rot diseases. Expression analyses of functional genes involved in the forskolin biosynthesis in C. forskohlii plants treated with CFRB1 endophyte under field conditions revealed differential upregulation of four C. forskohlii diterpene synthases (CfTPSs), CfTPS1, CfTPS2, CfTPS3 and CfTPS4, along with cytochrome P450 (CfCYP76AH15) and acyltransferase (CfACT1-8) genes. CFRB1 treatment reduced the severity of nematode infection and root rot in C. forskohlii plants by 81 and 78%, respectively. Overall, we demonstrate that cross-talk of plant-endophyte interaction in C. forskohlii is beneficial, leading to enhanced forskolin content through modulation of forskolin biosynthetic pathway genes along with increased plant yield and reduced disease incidence. Thus, endophytic isolate, A. faecalis (CFRB1), could be deployed as a novel bio-stimulant for enhancing in planta forskolin content during cultivation of C. forskohlii.
Asunto(s)
Alcaligenes faecalis/aislamiento & purificación , Colforsina/metabolismo , Endófitos/aislamiento & purificación , Hojas de la Planta/metabolismo , Plectranthus/metabolismo , Simbiosis , Animales , Resistencia a la Enfermedad , Interacciones Microbiota-Huesped , Nematodos , Enfermedades de las Plantas/parasitologíaAsunto(s)
Alcaligenes faecalis/aislamiento & purificación , Endocarditis/diagnóstico , Infecciones por Bacterias Gramnegativas/diagnóstico , Implantación de Prótesis de Válvulas Cardíacas/efectos adversos , Enfermedades Cutáneas Bacterianas/diagnóstico , Adulto , Diagnóstico Diferencial , Ecocardiografía Transesofágica , Endocarditis/complicaciones , Endocarditis/diagnóstico por imagen , Fiebre/etiología , Infecciones por Bacterias Gramnegativas/complicaciones , Infecciones por Bacterias Gramnegativas/diagnóstico por imagen , Humanos , Masculino , Tomografía de Emisión de Positrones , Enfermedades Cutáneas Bacterianas/complicaciones , Tomografía Computarizada por Rayos XRESUMEN
Soil-dwelling entomopathogenic nematodes (EPNs) kill arthropod hosts by injecting their symbiotic bacteria into the host hemolymph and feed on the bacteria and the tissue of the dying host for several generations cycles until the arthropod cadaver is completely depleted. The EPN-bacteria-arthropod cadaver complex represents a rich energy source for the surrounding opportunistic soil fungal biota and other competitors. We hypothesized that EPNs need to protect their food source until depletion and that the EPN symbiotic bacteria produce volatile and non-volatile exudations that deter different soil fungal groups in the soil. We isolated the symbiotic bacteria species (Alcaligenes faecalis) from the EPN Oscheius spp. and ran infectivity bioassays against entomopathogenic fungi (EPF) as well as against plant pathogenic fungi (PPF). We found that both volatile and non-volatile symbiotic bacterial exudations had negative effects on both EPF and PPF. Such deterrent function on functionally different fungal strains suggests a common mode of action of A. faecalis bacterial exudates, which has the potential to influence the structure of soil microbial communities, and could be integrated into pest management programs for increasing crop protection against fungal pathogens.
Asunto(s)
Alcaligenes faecalis/crecimiento & desarrollo , Antibiosis , Hongos/crecimiento & desarrollo , Control Biológico de Vectores/métodos , Rhabditoidea/microbiología , Alcaligenes faecalis/aislamiento & purificación , Animales , Antifúngicos/metabolismo , Pruebas de Sensibilidad MicrobianaRESUMEN
Vermicomposting of livestock manure using housefly larvae is a promising biotechnology for waste reduction and control of antibiotic pollution. Monensin (MON), an ionophore polyether antibiotic (IPA), is widely used in broiler feed to control coccidiosis. However, MON residues in litter have become a major source of pollution in the environment. In this work, we studied the efficiency of housefly larvae (Musca domestica) on monensin attenuation during a 12-day laboratory scale vermicomposting experiment. We observed a 94.99% reduction in MON concentration after four days in treatment groups, while it took twelve days to remove more than 94.71% of MON in the control group. We found that the bacterial community composition of the substrate was reshaped by housefly larvae. From the treatment groups, three MON-degrading bacterial strains were isolated and identified as Acinetobacter sp., Stenotrophomonas sp. and Alcaligenes sp. based on 16â¯S rRNA gene sequence analysis. These three strains were among dominant the bacteria in treated substrates, showing between 52.80% and 89.25% degradation of MON in mineral salt medium within 28 days. Furthermore, two MON-degrading bacteria (Stenotrophomonas sp. and Alcaligenes sp.) were more abundant in treatment groups and larvae gut groups compared with those in control groups. The abundance enhancement of MON-degrading bacteria was related to the change in ambient temperature and pH in the substrates, which were affected by housefly larvae activities. Our results confirm that housefly larvae can significantly accelerate degradation of MON in chicken manure by increasing the abundance of MON-degrading bacteria.
Asunto(s)
Moscas Domésticas , Larva , Microbiota , Monensina/química , Acinetobacter baumannii/aislamiento & purificación , Acinetobacter baumannii/metabolismo , Alcaligenes faecalis/aislamiento & purificación , Alcaligenes faecalis/metabolismo , Animales , Antibacterianos/química , Biodegradación Ambiental , Pollos , Compostaje , ADN Bacteriano/aislamiento & purificación , Fibras de la Dieta/análisis , Concentración de Iones de Hidrógeno , Ionóforos/química , Estiércol/análisis , Estiércol/microbiología , Análisis de Secuencia de ADN , Stenotrophomonas maltophilia/aislamiento & purificación , Stenotrophomonas maltophilia/metabolismo , TemperaturaRESUMEN
In this study, a bacterial strain exhibiting high selenite (Na2SeO3) tolerance and reduction capacity was isolated from the gut of Monochamus alternatus larvae and identified as Alcaligenes faecalis Se03. The isolate exhibited extreme tolerance to selenite (up to 120 mM) when grown aerobically. In the liquid culture medium, it was capable of reducing nearly 100% of 1.0 and 5.0 mM Na2SeO3 within 24 and 42 h, respectively, leading to the formation of selenium nanoparticles (SeNPs). Electron microscopy and energy dispersive X-ray analysis demonstrated that A. faecalis Se03 produced spherical electron-dense SeNPs with an average hydrodynamic diameter of 273.8 ± 16.9 nm, localized mainly in the extracellular space. In vitro selenite reduction activity and real-time PCR indicated that proteins such as sulfite reductase and thioredoxin reductase present in the cytoplasm were likely to be involved in selenite reduction and the SeNPs synthesis process in the presence of NADPH or NADH as electron donors. Finally, using Fourier-transform infrared spectrometry, protein and lipid residues were detected on the surface of the biogenic SeNPs. Based on these observations, A. faecalis Se03 has the potential to be an eco-friendly candidate for the bioremediation of selenium-contaminated soil/water and a bacterial catalyst for the biogenesis of SeNPs.
Asunto(s)
Alcaligenes faecalis/citología , Alcaligenes faecalis/metabolismo , Escarabajos/microbiología , Nanopartículas/metabolismo , Ácido Selenioso/metabolismo , Selenio/metabolismo , Alcaligenes faecalis/aislamiento & purificación , Animales , Nanopartículas/ultraestructura , Nanotecnología , Oxidación-ReducciónAsunto(s)
Bacteriemia/microbiología , Infecciones por Bordetella/diagnóstico , Bordetella , Huésped Inmunocomprometido , Anciano , Alcaligenes faecalis/aislamiento & purificación , Bacteriemia/diagnóstico , Bacteriemia/tratamiento farmacológico , Bacteriemia/inmunología , Bordetella/aislamiento & purificación , Infecciones por Bordetella/tratamiento farmacológico , Infecciones por Bordetella/inmunología , Neoplasias de la Mama/complicaciones , Neoplasias de la Mama/inmunología , Neoplasias de la Mama/patología , Infecciones Relacionadas con Catéteres/diagnóstico , Infecciones Relacionadas con Catéteres/tratamiento farmacológico , Infecciones Relacionadas con Catéteres/inmunología , Infecciones Relacionadas con Catéteres/microbiología , Coinfección , Femenino , Infecciones por Bacterias Gramnegativas/complicaciones , Infecciones por Bacterias Gramnegativas/diagnóstico , Infecciones por Bacterias Gramnegativas/tratamiento farmacológico , Infecciones por Bacterias Gramnegativas/inmunología , Humanos , Metástasis de la Neoplasia , Combinación Piperacilina y Tazobactam/uso terapéuticoRESUMEN
Pseudo-persistent organic pollutants, such as anionic surfactants (AS), are nowadays among the more complex problems that threaten the aquatic environments and other environmental compartments. The present work describes the identification and efficiency of a consortium, isolated from Algerian industrial wastewater, to remove three anionic surfactants (i.e., sodium dodecylbenzenesulfonate (SDBS), sodium dodecyl sulfate (SDS) and sodium lauryl ether sulfate (SLES)). The genetic analysis of 16S rRNA indicated that these strains are Alcaligenes faecalis, Enterobacter cloacae and Serratia marcescens. Under aerobic conditions, pH 7.0 and optimum temperature of 30⯰C, the mixed consortium allowed to degrade 85.1% of initial SDBS amount after 144â¯h of incubation with half-life of 20.8â¯h. While E. cloacae and S. marcescens pure strains eliminated 46% and 41% less SDBS respectively. Evenly, SDS was degraded at only 23.71% by A. faecalis strain. However, the degradation capacity of SDS by the consortium was very high (94.2%) with a half-life of 9.8â¯h. The SLES anionic surfactant showed a lower biodegradation by the consortium (47.53%) due to the presence of ether oxide units in the chemical structure of SLES which induced toxicity to the medium. The investigation of the biodegradation of this type of organic pollutants by microorganisms has recently become a key issue for the environmental protection area.
Asunto(s)
Alcaligenes faecalis/metabolismo , Enterobacter cloacae/metabolismo , Serratia marcescens/metabolismo , Tensoactivos/metabolismo , Aguas Residuales/microbiología , Alcaligenes faecalis/aislamiento & purificación , Biodegradación Ambiental , Enterobacter cloacae/aislamiento & purificación , Polietilenglicoles , ARN Ribosómico 16S , Serratia marcescens/aislamiento & purificación , Dodecil Sulfato de Sodio/química , Tensoactivos/químicaRESUMEN
Bioelectrochemical systems use microbes as catalysts for current production or consumption. Up to now only a few microbes have been demonstrated to be capable of both outward and inward extracellular electron transfer (EET) (i.e. bidirectional electron transfer). However, the mechanisms of electron exchange between microbes and extracellular solids remain uncertain. Here, we showed that Alcaligenes faecalis catalyzed an outward EET and generated electricity at a poised potential of +0.3V vs. SHE, whereas it conducted an inward EET for autotrophic denitrification at -0.5V vs. SHE. Both cyclic voltammetry and in situ electrochemical FTIR spectroscopy revealed that different redox components were utilized during the outward and inward EET. Electron transport inhibitor experiments indicated for the first time that complex I, II, III, and the quinone pool on the plasma membrane were involved in the bidirectional EET. Comparative proteomics showed that the protein expression profile of outward-EET biofilms differed greatly from those of inward-EET biofilms, implying that the pili and outer membrane proteins might be responsible for the interfacial outward and inward EET, respectively. These results suggest different electron transport conduits of A. faecalis biofilms could be used for bidirectional EET.
Asunto(s)
Alcaligenes faecalis/aislamiento & purificación , Técnicas Biosensibles , Proteómica , Alcaligenes faecalis/química , Fuentes de Energía Bioeléctrica , Biopelículas/crecimiento & desarrollo , Transporte de Electrón , Electrones , Quinonas/químicaRESUMEN
The potential for aerobic NO2- removal by Alcaligenes faecalis strain NR was investigated. 35 mg/L of NO2--N was removed by strain NR under aerobic conditions in the presence of NH4+. 15N-labeling experiment demonstrated that N2O and N2 were possible products during the aerobic nitrite removal process by strain NR. The key enzyme genes of nirK, norB and nosZ, which regulate the aerobic nitrite denitrification process, were successfully amplified from strain NR. The gene sequence analysis indicates that copper-containing nitrite reductase (NIRK) and periplasmic nitrous oxide reductase (NOSZ) were both hydrophilic protein and the transmembrane structures were absent, while nitric oxide reductase large subunit (NORB) was a hydrophobic and transmembrane protein. According to the three-dimensional structure and binding site analysis, the bulky and hydrophobic methionine residue proximity to the nitrite binding sites of NIRK was speculated to be related to the oxygen tolerance of NIRK from strain NR.
Asunto(s)
Alcaligenes faecalis/metabolismo , Proteínas Bacterianas/genética , Óxido Nitroso/metabolismo , Aerobiosis , Alcaligenes faecalis/enzimología , Alcaligenes faecalis/genética , Alcaligenes faecalis/aislamiento & purificación , Proteínas Bacterianas/metabolismo , Desnitrificación , Nitrito Reductasas/genética , Nitrito Reductasas/metabolismo , Nitritos/metabolismo , Oxidorreductasas/genética , Oxidorreductasas/metabolismo , Oxígeno/metabolismoRESUMEN
We found that 20 (10.6%) of 188 patients with chronic suppurative otitis media in Angola were co-colonized with fluoroquinolone-resistant Alcaligenes faecalis, commonly found in birds. A likely explanation for our findings was the use of bird feces by residents as a traditional remedy to prevent ear secretions caused by primary ear infection.
Asunto(s)
Alcaligenes faecalis/aislamiento & purificación , Columbidae/microbiología , Farmacorresistencia Bacteriana , Heces/microbiología , Otitis Media Supurativa/microbiología , Adolescente , Adulto , Angola , Animales , Antibacterianos/farmacología , Niño , Preescolar , Enfermedad Crónica , Estudios de Cohortes , Femenino , Fluoroquinolonas/farmacología , Humanos , Lactante , Masculino , Medicinas Tradicionales Africanas/efectos adversos , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Otitis Media Supurativa/etiologíaRESUMEN
The microbiological safety of spontaneously fermented foods is not always guaranteed due to the undefined fermenting microbial consortium and processing materials. In this study, two commonly consumed traditional condiments (iru and ogiri) and their respective raw seeds (locust bean and melon) purchased from markets in south-western Nigeria were assessed for bacterial diversity and mycotoxin contamination using 16S rRNA gene sequencing and liquid chromatography tandem mass spectrometry (LC-MS/MS), respectively. Two hundred isolates obtained from the raw seeds and condiments clustered into 10 operational taxonomic units (OTUs) and spanned 3 phyla, 10 genera, 14 species and 2 sub-species. Bacillus (25%) and Staphylococcus (23.5%) dominated other genera. Potentially pathogenic species such as Alcaligenes faecalis, Bacillus anthracis, Proteus mirabilis and Staphylococcus sciuri subsp. sciuri occurred in the samples, suggesting poor hygienic practice during production and/or handling of the condiments. A total of 48 microbial metabolites including 7 mycotoxins [3-nitropropionic acid, aflatoxin B1 (AFB1), AFB2, beauvericin, citrinin, ochratoxin A and sterigmatocystin] were quantified in the food samples. Melon and ogiri had detectable aflatoxin levels whereas locust bean and iru did not; the overall mycotoxin levels in the food samples were low. There is a need to educate processors/vendors of these condiments on good hygienic and processing practices.
Asunto(s)
Acacia/microbiología , Cucurbitaceae/microbiología , Alimentos Fermentados/microbiología , Micotoxinas/análisis , Semillas/microbiología , Acacia/química , Alcaligenes faecalis/aislamiento & purificación , Animales , Bacillus/aislamiento & purificación , Condimentos/microbiología , Cucurbitaceae/química , Fermentación , Inocuidad de los Alimentos , Nigeria , Proteus mirabilis/aislamiento & purificación , ARN Ribosómico 16S/genética , Semillas/química , Staphylococcus/aislamiento & purificación , Espectrometría de Masas en TándemRESUMEN
Carbapenemase-producing Gram-negative bacteria (CP-GNB) have increasingly spread worldwide, and different families of carbapenemases have been identified in various bacterial species. Here, we report the identification of five VIM metallo-ß-lactamase-producing Alcaligenes faecalis isolates associated with a small outbreak in a large hospital in Gaza, Palestine. Next-generation sequencing analysis showed blaVIM-2 is harbored by a chromosomal genomic island among three strains, while blaVIM-4 is carried by a novel plasmid in two strains.
Asunto(s)
Alcaligenes faecalis/efectos de los fármacos , Alcaligenes faecalis/genética , Antibacterianos/farmacología , beta-Lactamasas/genética , Alcaligenes faecalis/aislamiento & purificación , Farmacorresistencia Bacteriana/efectos de los fármacos , Farmacorresistencia Bacteriana/genética , Femenino , Genoma Bacteriano , Islas Genómicas , Infecciones por Bacterias Gramnegativas/epidemiología , Infecciones por Bacterias Gramnegativas/microbiología , Humanos , Masculino , Pruebas de Sensibilidad Microbiana , Medio Oriente/epidemiología , Filogenia , Polimorfismo de Nucleótido Simple , beta-Lactamasas/metabolismoRESUMEN
AIMS: The aim of this study is to report on the hydrolytic action of Alcaligenes faecalis isolated from soil samples and its ability to degrade ochratoxin A. METHODS AND RESULTS: An A. faecalis strain was identified and characterized by employing both a phenotypic analysis and 16S rDNA sequence analysis. The results show that this strain could degrade ochratoxin A efficiently but could not use it as a sole carbon source. Ochratoxin α was confirmed as a degradation product in the intracellular extract of A. faecalis using UPLC-MS/MS. Our results suggest that the biodegradation of ochratoxin A by the A. faecalis strain occurs through the hydrolysis of the ochratoxin A amide bond by a putative peptidase. This is the first report to date on the degradation of ochratoxin A by A. faecalis. CONCLUSION: The A. faecalis strain is presumably a suitable candidate for use in the biodegradation of ochratoxin A. SIGNIFICANCE AND IMPACT OF THE STUDY: Ochratoxin A, which is produced by some filamentous fungi, severely impacts human and animal health by contaminating several types of food and feed. Our study contributes to the identification of the function of A. faecalis 0D-1, which is capable of producing hydrolytic enzyme(s) to biodegrade ochratoxin A into nontoxic ochratoxin α, to minimize the risk associated with ochratoxin A exposure.
Asunto(s)
Alcaligenes faecalis/aislamiento & purificación , Alcaligenes faecalis/metabolismo , Ocratoxinas/metabolismo , Microbiología del Suelo , Alcaligenes faecalis/clasificación , Alcaligenes faecalis/genética , Animales , Biodegradación Ambiental , Bloqueadores de los Canales de Calcio/química , Bloqueadores de los Canales de Calcio/metabolismo , Humanos , Ocratoxinas/química , Suelo/química , Contaminantes del Suelo/química , Contaminantes del Suelo/metabolismo , Espectrometría de Masas en TándemRESUMEN
Contamination of the environment by heavy metals has been increasing in recent years due to industrial activities. Thus research involving microorganisms capable of surviving in multi-contaminated environments is extremely important. The objectives of the present study were to evaluate the removal of mercury alone and in the presence of cadmium, nickel and lead by four mercury-resistant microorganisms; estimate the removal of Cd, Ni and Pb; understand the mechanisms involved (reduction, siderophores, biofilms, biosorption and bioaccumulation) in the metal resistance of the isolate Pseudomonas sp. B50D; and determine the capacity of Pseudomonas sp. B50D in removing Hg, Cd, Ni and Pb from an industrial effluent. It was shown that the four isolates evaluated were capable of removing from 62% to 95% of mercury from a culture medium with no addition of other metals. The isolate Pseudomonas sp. B50D showed the best performance in the removal of mercury when evaluated concomitantly with other metals. This isolate was capable of removing 75% of Hg in the presence of Cd and 91% in the presence of Ni and Pb. With respect to the other metals it removed 60%, 15% and 85% of Cd, Ni and Pb, respectively. In tests with effluent, the isolate Pseudomonas sp. B50D removed 85% of Hg but did not remove the other metals. This isolate presented reduction, biosorption, biofilm production and siderophore production as its metal resistance mechanisms. Pseudomonas sp. B50D was thus a candidate with potential for application in the bioremediation of effluents with complex metal contaminations.
Asunto(s)
Adaptación Fisiológica/fisiología , Mercurio/metabolismo , Pseudomonas putida/metabolismo , Pseudomonas/metabolismo , Alcaligenes faecalis/aislamiento & purificación , Alcaligenes faecalis/metabolismo , Biodegradación Ambiental , Biopelículas , Cadmio/metabolismo , Residuos Industriales , Plomo/metabolismo , Metales Pesados/aislamiento & purificación , Níquel/metabolismo , Pseudomonas/aislamiento & purificación , Pseudomonas putida/aislamiento & purificación , Sideróforos/metabolismoRESUMEN
The changes induced in bacterial strains under stress conditions provide an insight into metal resistance strategies. Trivalent chromium resistant bacterium were isolated and identified by 16S rRNA gene sequencing and designated as Alcaligenes faecalis VITSIM2. The growth pattern was monitored. The organism also showed resistance to copper, cadmium, and certain antibiotics. The differentially expressed proteins in SDS PAGE were identified by mass spectrometry as flagellin and 50S ribosomal L36 protein. The morphological changes were identified by scanning electron microscopy. The changes in the cell wall content were estimated by peptidoglycan analysis and transformation of phosphates was detected by 31 P NMR. Flow cytometry was employed to measure the membrane integrity, esterase activity and intracellular pH. In conclusion spectrum of proteomic, physiological, and morphological alterations was observed that aid the organism to overcome chromium stress.