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1.
BMC Infect Dis ; 23(1): 414, 2023 Jun 19.
Artículo en Inglés | MEDLINE | ID: mdl-37337134

RESUMEN

BACKGROUND: A key factor driving the development and maintenance of antibacterial resistance (ABR) is individuals' use of antibiotics (ABs) to treat illness. To better understand motivations and context for antibiotic use we use the concept of a patient treatment-seeking pathway: a treatment journey encompassing where patients go when they are unwell, what motivates their choices, and how they obtain antibiotics. This paper investigates patterns and determinants of patient treatment-seeking pathways, and how they intersect with AB use in East Africa, a region where ABR-attributable deaths are exceptionally high. METHODS: The Holistic Approach to Unravelling Antibacterial Resistance (HATUA) Consortium collected quantitative data from 6,827 adult outpatients presenting with urinary tract infection (UTI) symptoms in Kenya, Tanzania, and Uganda between February 2019- September 2020, and conducted qualitative in-depth patient interviews with a subset (n = 116). We described patterns of treatment-seeking visually using Sankey plots and explored explanations and motivations using mixed-methods. Using Bayesian hierarchical regression modelling, we investigated the associations between socio-demographic, economic, healthcare, and attitudinal factors and three factors related to ABR: self-treatment as a first step, having a multi-step treatment pathway, and consuming ABs. RESULTS: Although most patients (86%) sought help from medical facilities in the first instance, many (56%) described multi-step, repetitive treatment-seeking pathways, which further increased the likelihood of consuming ABs. Higher socio-economic status patients were more likely to consume ABs and have multi-step pathways. Reasons for choosing providers (e.g., cost, location, time) were conditioned by wider structural factors such as hybrid healthcare systems and AB availability. CONCLUSION: There is likely to be a reinforcing cycle between complex, repetitive treatment pathways, AB consumption and ABR. A focus on individual antibiotic use as the key intervention point in this cycle ignores the contextual challenges patients face when treatment seeking, which include inadequate access to diagnostics, perceived inefficient public healthcare and ease of purchasing antibiotics without prescription. Pluralistic healthcare landscapes may promote more complex treatment seeking and therefore inappropriate AB use. We recommend further attention to healthcare system factors, focussing on medical facilities (e.g., accessible diagnostics, patient-doctor interactions, information flows), and community AB access points (e.g., drug sellers).


Asunto(s)
Antibacterianos , Atención a la Salud , Adulto , Humanos , Investigación Cualitativa , Teorema de Bayes , Uganda , Antibacterianos/farmacología , Antibacterianos/uso terapéutico
2.
Int J Mol Sci ; 23(9)2022 Apr 23.
Artículo en Inglés | MEDLINE | ID: mdl-35563074

RESUMEN

Lactococcus garvieae causes infectious diseases in animals and is considered an emerging zoonotic pathogen involved in human clinical conditions. In silico analysis of plasmid pLG50 of L. garvieae Lg-Granada, an isolate from a patient with endocarditis, revealed the presence of two gene clusters (orf46-47 and orf48-49), each one encoding a novel putative bacteriocin, i.e., garvicin AG1 (GarAG1; orf46) and garvicin AG2 (GarAG2; orf48), and their corresponding immunity proteins (orf47 and orf49). The chemically synthesised bacteriocins GarAG1 and GarAG2 presented inhibitory activity against pathogenic L. garvieae strains, with AG2 also being active against Listeria monocytogenes, Listeria ivanovii and Enterococcus faecalis. Genetic organisation, amino acid sequences and antimicrobial activities of GarAG1 and GarAG2 indicate that they belong to linear non-pediocin-like one-peptide class IId bacteriocins. Gram-positive bacteria that were sensitive to GarAG2 were also able to ferment mannose, suggesting that this bacteriocin could use the mannose phosphotransferase transport system (Man-PTS) involved in mannose uptake as a receptor in sensitive strains. Intriguingly, GarAG1 and GarAG2 were highly active against their own host, L. garvieae Lg-Granada, which could be envisaged as a new strategy to combat pathogens via their own weapons.


Asunto(s)
Bacteriocinas , Animales , Bacteriocinas/metabolismo , Bacterias Grampositivas/metabolismo , Humanos , Lactococcus/metabolismo , Manosa/metabolismo
3.
J Evol Biol ; 33(1): 101-111, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31610055

RESUMEN

Bacteria eliminate competitors via 'chemical warfare' with bacteriocins. Some species appear to adjust bacteriocin production conditionally in response to the social environment. We tested whether variation in the cost and benefit of producing bacteriocins could explain such conditional behaviour, in the bacteria Lactobacillus plantarum. We found that: (a) bacterial bacteriocin production could be upregulated by either the addition of a synthetic autoinducer peptide (PLNC8IF; signalling molecule), or by a plasmid which constitutively encodes for the production of this peptide; (b) bacteriocin production is costly, leading to reduced growth when grown in poor and, to a lesser extent, in rich media; (c) bacteriocin production provides a fitness advantage, when grown in competition with sensitive strains; and (d) the fitness benefits provided by bacteriocin production are greater at higher cell densities. These results show how the costs and benefits of upregulating bacteriocin production can depend upon abiotic and biotic conditions.


Asunto(s)
Bacteriocinas/genética , Bacteriocinas/metabolismo , Lactobacillus plantarum/genética , Lactobacillus plantarum/metabolismo , Percepción de Quorum/genética , Análisis Costo-Beneficio , Regulación hacia Arriba
4.
BMC Microbiol ; 16: 37, 2016 Mar 12.
Artículo en Inglés | MEDLINE | ID: mdl-26969428

RESUMEN

BACKGROUND: Lactobacillus gasseri is one of the dominant Lactobacillus species in the vaginal ecosystem. Some strains of this species have a high potential for being used as probiotics in order to maintain vaginal homeostasis, since they may confer colonization resistance against pathogens in the vagina by direct inhibition through production of antimicrobial compounds, as bacteriocins. In this work we have studied bacteriocin production of gassericin E (GasE), a novel bacteriocin produced by L. gasseri EV1461, a strain isolated from the vagina of a healthy woman, and whose production was shown to be promoted by the presence of certain specific bacteria in co-culture. Biochemical and genetic characterization of this novel bacteriocin are addressed. RESULTS: We found that the inhibitory spectrum of L. gasseri EV1461 was broad, being directed to species both related and non-related to the producing strain. Interestingly, L. gasseri EV1461 inhibited the grown of pathogens usually associated with bacterial vaginosis (BV). The antimicrobial activity was due to the production of a novel bacteriocin, gassericin E (GasE). Production of this bacteriocin in broth medium only was achieved at high cell densities. At low cell densities, bacteriocin production ceased and only was restored after the addition of a supernatant from a previous bacteriocin-producing EV1461 culture (autoinduction), or through co-cultivation with several other Gram-positive strains (inducing bacteria). DNA sequence of the GasE locus revealed the presence of two putative operons which could be involved in biosynthesis and immunity of this bacteriocin (gaeAXI), and in regulation, transport and processing (gaePKRTC). The gaePKR encodes a putative three-component regulatory system, involving an autoinducer peptide (GaeP), a histidine protein kinase (GaeK) and a response regulator (GaeR), while the gaeTC encodes for an ABC transporter (GaeT) and their accessory protein (GaeC), involved in transport and processing of the bacteriocin. The gaeAXI, encodes for the bacteriocin gassericin E (GasE), a putative peptide bacteriocin (GaeX), and their immunity protein (GaeI). CONCLUSIONS: The origin of the strain (vagina of healthy woman) and its ability to produce bacteriocins with inhibitory activity against vaginal pathogens may be an advantage for using L. gasseri EV1461 as a probiotic strain to fight and/or prevent bacterial infections as bacterial vaginosis (BV), since it could be better adapted to live and compete into the vaginal environment.


Asunto(s)
Antibacterianos/aislamiento & purificación , Antibacterianos/farmacología , Bacteriocinas/aislamiento & purificación , Bacteriocinas/farmacología , Lactobacillus/metabolismo , Vagina/microbiología , Adulto , Antibacterianos/metabolismo , Bacterias/efectos de los fármacos , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Bacteriocinas/genética , Bacteriocinas/metabolismo , Femenino , Voluntarios Sanos , Humanos , Lactobacillus/química , Lactobacillus/clasificación , Lactobacillus/aislamiento & purificación
5.
Int J Syst Evol Microbiol ; 65(Pt 6): 1895-1901, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25792368

RESUMEN

Three isolates originating from Spanish-style green-olive fermentations in a manufacturing company in the province of Seville, Spain, were taxonomically characterized by a polyphasic approach. This included a phylogenetic analysis based on 16S rRNA gene sequences and multi-locus sequence analysis (MLSA) based on pyrH, recA, rpoA, gyrB and mreB genes. The isolates shared 98.0 % 16S rRNA gene sequence similarity with Vibrio xiamenensis G21T. Phylogenetic analysis based on 16S rRNA gene sequences using the neighbour-joining and maximum-likelihood methods showed that the isolates fell within the genus Vibrio and formed an independent branch close to V. xiamenensis G21T. The maximum-parsimony method grouped the isolates to V. xiamenensis G21T but forming two clearly separated branches. Phylogenetic trees based on individual pyrH, recA, rpoA, gyrB and mreB gene sequences revealed that strain IGJ1.11T formed a clade alone or with V. xiamenensis G21T. Sequence similarities of the pyrH, recA, rpoA, gyrB and mreB genes between strain IGJ1.11T and V. xiamenensis G21T were 86.7, 85.7, 97.3, 87.6 and 84.8 %, respectively. MLSA of concatenated sequences showed that strain IGJ1.11T and V. xiamenensis G21T are two clearly separated species that form a clade, which we named Clade Xiamenensis, that presented 89.7 % concatenated gene sequence similarity, i.e. less than 92 %. The major cellular fatty acids (>5 %) of strain IGJ1.11T were summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), C16 : 0 and summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c). Enzymic activity profiles, sugar fermentation patterns and DNA G+C content (52.9 mol%) differentiated the novel strains from the closest related members of the genus Vibrio. The name Vibrio olivae sp. nov. is proposed for the novel species. The type strain is IGJ1.11T ( = CECT 8064T = DSM 25438T).


Asunto(s)
Fermentación , Microbiología de Alimentos , Olea/microbiología , Filogenia , Vibrio/clasificación , Técnicas de Tipificación Bacteriana , Composición de Base , ADN Bacteriano/genética , Ácidos Grasos/química , Genes Bacterianos , Datos de Secuencia Molecular , Tipificación de Secuencias Multilocus , Hibridación de Ácido Nucleico , ARN Ribosómico 16S/genética , Técnica del ADN Polimorfo Amplificado Aleatorio , Análisis de Secuencia de ADN , España , Vibrio/genética , Vibrio/aislamiento & purificación
6.
Int J Syst Evol Microbiol ; 64(Pt 9): 2980-2985, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-24912823

RESUMEN

Five strains of Gram-stain-positive bacteria were isolated from anomalous fermentations occurring in post-packaging of sealed airtight food-grade plastic pouches of Spanish-style green olives. These isolates could be grouped into two sets, which showed a similarity in their respective 16S rRNA gene sequences of 98.40 and 98.44 % with Propionibacterium acidipropionici NCFB 563 and 98.33 and 98.11 % with Propionibacterium microaerophilum M5(T), respectively, and a similarity of 99.41 % between them. The 16S rRNA gene phylogeny revealed that the isolates grouped into two statistically well-supported clusters separate from P. acidipropionici NCFB 563 and P. microaerophilum M5(T). Enzymic activity profiles as well as fermentation patterns differentiated these two novel bacteria from other members of the genus Propionibacterium. Finally, phenotypic, genotypic and phylogenetic data, supported the proposal of two novel species of the genus Propionibacterium, for which the names Propionibacterium olivae sp. nov. (type strain, IGBL1(T) = CECT 8061(T) = DSM 25436(T)) and Propionibacterium damnosum sp. nov. (type strain, IGBL13(T) = CECT 8062(T) = DSM 25450(T)) are proposed.


Asunto(s)
Microbiología de Alimentos , Olea/microbiología , Filogenia , Propionibacterium/clasificación , Técnicas de Tipificación Bacteriana , ADN Bacteriano/genética , Fermentación , Frutas/microbiología , Datos de Secuencia Molecular , Hibridación de Ácido Nucleico , Propionibacterium/genética , Propionibacterium/aislamiento & purificación , ARN Ribosómico 16S/genética , Técnica del ADN Polimorfo Amplificado Aleatorio , Análisis de Secuencia de ADN , España
7.
Int J Syst Evol Microbiol ; 64(Pt 8): 2534-2539, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-24812366

RESUMEN

Six strains of a hitherto unknown, Gram-stain-positive coccus were recovered from samples of Spanish-style green-olive fermentations. The 16S rRNA gene sequences from these isolates shared 98.7% and 98.5% of their nucleotide positions with those from Enterococcus saccharolyticus subsp. taiwanensis 812(T) and from E. saccharolyticus subsp. saccharolyticus ATCC 43076(T), respectively. The sequence of the rpoA gene in the isolates was 95% similar to that of E. saccharolyticus CECT 4309(T) ( = ATCC 43076(T)). The 16S rRNA and rpoA gene phylogenies revealed that the isolates grouped in a statistically well-supported cluster separate from E. saccharolyticus. Enzyme activity profiles as well as fermentation patterns differentiated the novel bacteria from other members of the Enterococcus genus. Finally, phenotypic, genotypic and phylogenetic data supported the identification of a novel species of the genus Enterococcus, for which the name Enterococcus olivae sp. nov. is proposed. The type strain is IGG16.11(T) ( = CECT 8063(T) = DSM 25431(T)).


Asunto(s)
Enterococcus/clasificación , Fermentación , Microbiología de Alimentos , Olea/microbiología , Filogenia , Técnicas de Tipificación Bacteriana , Composición de Base , ADN Bacteriano/genética , Enterococcus/genética , Enterococcus/aislamiento & purificación , Datos de Secuencia Molecular , Hibridación de Ácido Nucleico , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , España
8.
Food Microbiol ; 42: 154-65, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-24929732

RESUMEN

We have studied the microbiota associated to Spanish-style green olive fermentations, attending to its dynamics along the time. Twenty 10-tonne fermenters were selected from two large table-olive manufacturing companies in southern Spain. While culture-dependent methodology was used to isolate the microorganisms, molecular methods were used to identify the isolates. A total of 1070 isolates were obtained, resulting in 929 bacterial and 141 yeast isolates. Thirty seven different bacterial species were isolated, belonging to 18 different genera, while 12 yeast species were isolated, belonging to 7 distinct genera. This fermentation was dominated by the species Lactobacillus pentosus, while its accessory microbiota was variable and depended on the fermentation stage and the actual fermentation yard ("patio"). It was noticeable the abundance of lactic acid bacteria isolates, belonging to 16 different species. Twenty bacterial species were isolated for the first time from Spanish-style green olive fermentations, while 17 had not been described before in any table olive preparation. The genera Brachybacterium, Paenibacillus, Sporolactobacillus, Paracoccus and Yersinia had not been cited before from any table olive preparation. Saccharomyces cerevisiae and Candida thaimueangensis appeared to dominate the yeast microbiota. Candida butyri/asseri and Rhodotorula mucilaginosa had not been described before from Spanish-style preparations, while Saturnispora mendoncae was isolated for the first time from any table olive preparation. Biodiversity was analysed through different alpha and beta indexes which showed the evolution of the microbiota over time.


Asunto(s)
Bacterias/aislamiento & purificación , Biodiversidad , Frutas/microbiología , Olea/microbiología , Levaduras/aislamiento & purificación , Bacterias/clasificación , Bacterias/genética , Bacterias/metabolismo , Fermentación , Microbiología de Alimentos/instrumentación , España , Levaduras/clasificación , Levaduras/genética , Levaduras/metabolismo
9.
JAC Antimicrob Resist ; 6(1): dlae019, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38372000

RESUMEN

Background: In low- and middle-income countries, antibiotics are often prescribed for patients with symptoms of urinary tract infections (UTIs) without microbiological confirmation. Inappropriate antibiotic use can contribute to antimicrobial resistance (AMR) and the selection of MDR bacteria. Data on antibiotic susceptibility of cultured bacteria are important in drafting empirical treatment guidelines and monitoring resistance trends, which can prevent the spread of AMR. In East Africa, antibiotic susceptibility data are sparse. To fill the gap, this study reports common microorganisms and their susceptibility patterns isolated from patients with UTI-like symptoms in Kenya, Tanzania and Uganda. Within each country, patients were recruited from three sites that were sociodemographically distinct and representative of different populations. Methods: UTI was defined by the presence of >104 cfu/mL of one or two uropathogens in mid-stream urine samples. Identification of microorganisms was done using biochemical methods. Antimicrobial susceptibility testing was performed by the Kirby-Bauer disc diffusion assay. MDR bacteria were defined as isolates resistant to at least one agent in three or more classes of antimicrobial agents. Results: Microbiologically confirmed UTI was observed in 2653 (35.0%) of the 7583 patients studied. The predominant bacteria were Escherichia coli (37.0%), Staphylococcus spp. (26.3%), Klebsiella spp. (5.8%) and Enterococcus spp. (5.5%). E. coli contributed 982 of the isolates, with an MDR proportion of 52.2%. Staphylococcus spp. contributed 697 of the isolates, with an MDR rate of 60.3%. The overall proportion of MDR bacteria (n = 1153) was 50.9%. Conclusions: MDR bacteria are common causes of UTI in patients attending healthcare centres in East African countries, which emphasizes the need for investment in laboratory culture capacity and diagnostic algorithms to improve accuracy of diagnosis that will lead to appropriate antibiotic use to prevent and control AMR.

10.
PLOS Glob Public Health ; 4(2): e0002709, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38363770

RESUMEN

Antibacterial resistance (ABR) is a major public health threat. An important accelerating factor is treatment-seeking behaviour, including inappropriate antibiotic (AB) use. In many low- and middle-income countries (LMICs) this includes taking ABs with and without prescription sourced from various providers, including health facilities and community drug sellers. However, investigations of complex treatment-seeking, AB use and drug resistance in LMICs are scarce. The Holistic Approach to Unravel Antibacterial Resistance in East Africa (HATUA) Consortium collected questionnaire and microbiological data from adult outpatients with urinary tract infection (UTI)-like symptoms presenting at healthcare facilities in Kenya, Tanzania and Uganda. Using data from 6,388 patients, we analysed patterns of self-reported treatment seeking behaviours ('patient pathways') using process mining and single-channel sequence analysis. Among those with microbiologically confirmed UTI (n = 1,946), we used logistic regression to assess the relationship between treatment seeking behaviour, AB use, and the likelihood of having a multi-drug resistant (MDR) UTI. The most common treatment pathway for UTI-like symptoms in this sample involved attending health facilities, rather than other providers like drug sellers. Patients from sites in Tanzania and Uganda, where over 50% of patients had an MDR UTI, were more likely to report treatment failures, and have repeat visits to providers than those from Kenyan sites, where MDR UTI proportions were lower (33%). There was no strong or consistent relationship between individual AB use and likelihood of MDR UTI, after accounting for country context. The results highlight the hurdles East African patients face in accessing effective UTI care. These challenges are exacerbated by high rates of MDR UTI, suggesting a vicious cycle of failed treatment attempts and sustained selection for drug resistance. Whilst individual AB use may contribute to the risk of MDR UTI, our data show that factors related to context are stronger drivers of variations in ABR.

11.
Appl Environ Microbiol ; 79(14): 4336-46, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23666326

RESUMEN

Lactococcus garvieae 21881, isolated in a human clinical case, produces a novel class IId bacteriocin, garvicin A (GarA), which is specifically active against other L. garvieae strains, including fish- and bovine-pathogenic isolates. Purification from active supernatants, sequence analyses, and plasmid-curing experiments identified pGL5, one of the five plasmids found in L. garvieae [M. Aguado-Urda et al., PLoS One 7(6):e40119, 2012], as the coding plasmid for the structural gene of GarA (lgnA), its putative immunity protein (lgnI), and the ABC transporter and its accessory protein (lgnC and lgnD). Interestingly, pGL5-cured strains were still resistant to GarA. Other putative bacteriocins encoded by the remaining plasmids were not detected during purification, pointing to GarA as the main inhibitor secreted by L. garvieae 21881. Mode-of-action studies revealed a potent bactericidal activity of GarA. Moreover, transmission microscopy showed that GarA seems to act by inhibiting septum formation in L. garvieae cells. This potent and species-specific inhibition by GarA holds promise for applications in the prevention or treatment of infections caused by pathogenic strains of L. garvieae in both veterinary and clinical settings.


Asunto(s)
Bacteriocinas/aislamiento & purificación , Bacteriocinas/farmacología , Infecciones por Bacterias Grampositivas/microbiología , Infecciones por Bacterias Grampositivas/veterinaria , Lactococcus/química , Lactococcus/efectos de los fármacos , Anciano , Secuencia de Aminoácidos , Animales , Bacteriocinas/química , Bacteriocinas/genética , Búfalos , Bovinos , ADN Bacteriano/química , ADN Bacteriano/genética , ADN Bacteriano/metabolismo , Electroforesis en Gel de Poliacrilamida , Femenino , Enfermedades de los Peces/microbiología , Peces , Humanos , Lactococcus/genética , Lactococcus/metabolismo , Masculino , Mastitis Bovina/microbiología , Microscopía Electrónica de Transmisión/veterinaria , Plásmidos , Reacción en Cadena de la Polimerasa , Alineación de Secuencia , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción
12.
BMC Microbiol ; 13: 288, 2013 Dec 10.
Artículo en Inglés | MEDLINE | ID: mdl-24325647

RESUMEN

BACKGROUND: Recent studies have shown that mammalian milk represents a continuous supply of commensal bacteria, including enterococci. The objectives of this study were to evaluate the presence of enterococci in milk of different species and to screen them for several genetic and phenotypic traits of clinical significance among enterococci. RESULTS: Samples were obtained from, at least, nine porcine, canine, ovine, feline and human healthy hosts. Enterococci could be isolated, at a concentration of 1.00 × 10(2) -1.16 × 10(3) CFU/ml, from all the porcine samples and, also from 85, 50, 25 and 25% of the human, canine, feline and ovine ones, respectively. They were identified as Enterococcus faecalis, Enterococcus faecium, Enterococcus hirae, Enterococcus casseliflavus and Enterococcus durans. Among the 120 initial enterococcal isolates, 36 were selected on the basis of their different PFGE profiles and further characterized. MLST analysis revealed a wide diversity of STs among the E. faecalis and E. faecium strains, including some frequently associated to hospital infections and novel STs. All the E. faecalis strains possessed some of the potential virulence determinants (cad, ccf, cob, cpd, efaA(fs), agg2, gelE, cylA, esp(fs)) assayed while the E. faecium ones only harboured the efaA(fm) gene. All the tested strains were susceptible to tigecycline, linezolid and vancomycin, and produced tyramine. Their susceptibility to the rest of the antimicrobials and their ability to produce other biogenic amines varied depending on the strain. Enterococci strains isolated from porcine samples showed the widest spectrum of antibiotic resistance. CONCLUSIONS: Enterococci isolated from milk of different mammals showed a great genetic diversity. The wide distribution of virulence genes and/or antibiotic resistance among the E. faecalis and E. faecium isolates indicates that they can constitute a reservoir of such traits and a risk to animal and human health.


Asunto(s)
Aminas Biogénicas/metabolismo , Farmacorresistencia Bacteriana , Enterococcus/aislamiento & purificación , Leche Humana/microbiología , Leche/microbiología , Factores de Virulencia/genética , Animales , Antibacterianos/farmacología , Electroforesis en Gel de Campo Pulsado , Enterococcus/efectos de los fármacos , Enterococcus/genética , Enterococcus/metabolismo , Femenino , Variación Genética , Humanos , Pruebas de Sensibilidad Microbiana , Tipificación de Secuencias Multilocus , Reacción en Cadena de la Polimerasa
13.
Food Microbiol ; 33(1): 40-7, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23122499

RESUMEN

We describe the bacteriocin-production phenotype in a group of eight singular bacteriocinogenic Lactobacillus plantarum strains with three distinct genotypes regarding the plantaricin locus. Genotyping of these strains revealed the existence of two different plantaricin-production regulatory operons, plNC8-plNC8HK-plnD or plnABCD, involving three-component systems controlled each of them by a specific autoinducer peptide (AIP), i.e. PLNC8IF or PlnA. While all of the strains produced antimicrobial activity when growing on solid medium, most of them halted this production when cultured in broth, thus reflecting the functionality of regulatory mechanisms. Antimicrobial activity in broth cultures was re-established or enhanced when the specific AIP was added to the culture or by coculturing with specific bacterial strains. The latter trait appeared to be widespread in bacteriocinogenic L. plantarum strains independently of the regulatory system used to regulate bacteriocin production or the specific bacteriocins produced. The induction spectrum through coculture, i.e. the pattern of bacterial strains able to induce bacteriocin production, was characteristic of each individual L. plantarum strain. Also, the ability of some bacteria to induce bacteriocin production in L. plantarum by coculture appeared to be strain specific. The fact that induction of bacteriocin production by coculturing appeared to be a common feature in L. plantarum can be exploited accordingly to enhance the viability of this species in food and feed fermentations, as well as to contribute to probiotic functionality when colonising the gastrointestinal tract.


Asunto(s)
Bacteriocinas/biosíntesis , Lactobacillus plantarum/metabolismo , Operón , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Técnicas de Cocultivo , Regulación Bacteriana de la Expresión Génica , Lactobacillus plantarum/genética , Lactobacillus plantarum/crecimiento & desarrollo , Especificidad de la Especie
14.
Food Microbiol ; 33(1): 90-6, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23122506

RESUMEN

The effect of NaCl on plantaricin production by five Lactobacillus plantarum strains was investigated. Plantaricin production in these strains was found to be regulated by three-component regulatory systems ruled by two different autoinducer peptides (AIPs), either PLNC8IF or Plantaricin A. Bacteriocin activity exhibited by these strains came to a halt in liquid medium containing NaCl concentrations of or above 2%. In contrast, bacteriocin activity was still observed when the producing strains were growing on solid medium containing up to 4% NaCl. Bacteriocin activity in liquid medium containing up to 2% NaCl could be restored by coculturing the producing strains with a selected plantaricin-production inducing strain of Lactococcus lactis. Growth of these bacteriocinogenic L. plantarum strains was monitored in traditional Spanish-style green olive fermentations. Survival of these strains could not be enhanced when provided with a range of plantaricin-production inducing mechanisms previously described, such as constitutive AIP production or coinoculation with a specific bacteriocin-production inducing strain of L. lactis. Our results suggest that it is advisable the use of constitutive bacteriocin producers, or at least non-AIP-dependant ones, as starters for olive fermentations due to the intrinsic physical characteristics of this food fermentation, especially the high salt concentration of the brines currently used.


Asunto(s)
Bacteriocinas/biosíntesis , Lactobacillus plantarum/metabolismo , Olea/microbiología , Cloruro de Sodio/metabolismo , Bacteriocinas/metabolismo , Fermentación , Lactobacillus plantarum/crecimiento & desarrollo , Olea/metabolismo , España
15.
Pathogens ; 12(2)2023 Jan 24.
Artículo en Inglés | MEDLINE | ID: mdl-36839452

RESUMEN

BACKGROUND: There is a growing body of evidence on the potential involvement of coagulase-negative Staphylococci (CoNS) in causing urinary tract infections (UTIs). The aim of this study was to delineate virulence potential, antimicrobial resistance genes, and sequence types of CoNS isolated from patients with UTI symptoms and pyuria in Tanzania. METHODS: CoNS from patients with UTI symptoms and more than 125 leucocytes/µL were retrieved, subcultured, and whole-genome sequenced. RESULTS: Out of 65 CoNS isolates, 8 species of CoNS were identified; Staphylococcus haemolyticus, n = 27 (41.5%), and Staphylococcus epidermidis, n = 24 (36.9%), were predominant. The majority of S. haemolyticus were sequence type (ST) 30, with 8 new ST138-145 reported, while the majority of S. epidermidis were typed as ST490 with 7 new ST1184-1190 reported. Sixty isolates (92.3%) had either one or multiple antimicrobial resistance genes. The most frequently detected resistance genes were 53 (21%) dfrG, 32 (12.9%) blaZ, and 26 (10.5%) mecA genes conferring resistance to trimethoprim, penicillin, and methicillin, respectively. Out of 65 isolates, 59 (90.8%) had virulence genes associated with UTI, with a predominance of the icaC 47 (46.5%) and icaA 14 (13.9%) genes. Conclusion:S. haemolyticus and S. epidermidis harboring icaC, dfrG, blaZ, and mecA genes were the predominant CoNS causing UTI in Tanzania. Laboratories should carefully interpret the significant bacteriuria due to CoNS in relation to UTI symptoms and pyuria before labeling them as contaminants. Follow-up studies to document the outcome of the treated patients is needed to add more evidence that CoNS are UTI pathogens.

16.
IJID Reg ; 7: 170-175, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37069922

RESUMEN

Background: Urogenital pathogens such as Chlamydia trachomatis, Neisseria gonorrhoeae, Mycoplasma genitalium and Trichomonas vaginalis have been reported to cause pyuria, however they are not routinely cultured from urine samples of patients clinically diagnosed to have urinary tract infections (UTI). In this study, pathogen specific PCR was done to identify the urogenital pathogens in the urine samples among clinically diagnosed UTI patients with negative routine urine culture. Methods: A cross-sectional study was conducted involving 227 archived urine samples from clinically diagnosed UTI patients with positive leucocyte esterase but negative urine culture results. The urogenital pathogens were detected using pathogen specific singleplex PCR. Data were cleaned and analyzed using STATA version 15. Results: The median age of patients was 31[IQR 23 - 51] years and the majority (174, 76.7%) were females. Two thirds of patients had history of antibiotic use two weeks prior to recruitment (154, 67.8%). A total of 62(27.3%) urine samples were positive for at least one urogenital pathogen. Of 62 positive samples, 9 had two urogenital pathogens and 1 had three urogenital pathogens. The most predominant urogenital pathogen detected was Neisseria gonorrhoeae 25(34.2%) and Trichomonas vaginalis 24(32.9%). Being female (aOR 2.4; 95% CI: 1.04 - 5.49; p-value 0.039) and having history of using antibiotics in the past two weeks (aOR 1.9; 95%CI: 1.04 - 3.60; p-value 0.036) was independently associated with the presence of urogenital pathogens. Conclusion: More than a quarter of female patients with clinical symptoms of UTI and routine urine culture negative results were infected with urogenital pathogens mainly Neisseria gonorrhoeae and Trichomonas vaginalis. Further research with a larger sample set in a range of settings is required to understand the implications of these finding generally.

17.
medRxiv ; 2023 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-36945627

RESUMEN

Antibacterial resistance (ABR) is a major public health threat. An important accelerating factor is treatment-seeking behaviours, including inappropriate antibiotic (AB) use. In many low- and middle-income countries (LMICs) this includes taking ABs with and without prescription sourced from various providers, including health facilities and community drug sellers. However, investigations of complex treatment-seeking, AB use and drug resistance in LMICs are scarce. The Holistic Approach to Unravel Antibacterial Resistance in East Africa (HATUA) Consortium collected questionnaire and microbiological data from 6,827 adult outpatients with urinary tract infection (UTI)-like symptoms presenting at healthcare facilities in Kenya, Tanzania and Uganda. Among 6,388 patients we analysed patterns of self-reported treatment seeking behaviours ('patient pathways') using process mining and single-channel sequence analysis. Of those with microbiologically confirmed UTI (n=1,946), we used logistic regression to assessed the relationship between treatment seeking behaviour, AB use, and likelihood of having a multi-drug resistant (MDR) UTI. The most common treatment pathways for UTI-like symptoms included attending health facilities, rather than other providers (e.g. drug sellers). Patients from the sites sampled in Tanzania and Uganda, where prevalence of MDR UTI was over 50%, were more likely to report treatment failures, and have repeated visits to clinics/other providers, than those from Kenyan sites, where MDR UTI rates were lower (33%). There was no strong or consistent relationship between individual AB use and risk of MDR UTI, after accounting for country context. The results highlight challenges East African patients face in accessing effective UTI treatment. These challenges increase where rates of MDR UTI are higher, suggesting a reinforcing circle of failed treatment attempts and sustained selection for drug resistance. Whilst individual behaviours may contribute to the risk of MDR UTI, our data show that factors related to context are stronger drivers of ABR.

18.
J Bacteriol ; 194(16): 4466-7, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22843595

RESUMEN

Streptococcus salivarius is a commensal species commonly found in the human oropharyngeal tract. Some strains of this species have been developed for use as oral probiotics, while others have been associated with a variety of opportunistic human infections. Here, we report the complete sequence of strain PS4, which was isolated from breast milk of a healthy woman.


Asunto(s)
ADN Bacteriano/química , ADN Bacteriano/genética , Genoma Bacteriano , Leche Humana/microbiología , Análisis de Secuencia de ADN , Streptococcus/genética , Humanos , Datos de Secuencia Molecular , Streptococcus/aislamiento & purificación
19.
Appl Microbiol Biotechnol ; 94(5): 1279-87, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22526789

RESUMEN

Lactobacillus salivarius CECT 5713, isolated from human milk, has immunomodulatory, anti-inflammatory and antiinfectious properties, as revealed by several in vitro and in vivo assays, which suggests a strong potential as a probiotic strain. In this work, the relationships between several genetic features of L. salivarius CECT 5713 and the corresponding phenotypes were evaluated. Although it contains a plasmid-encoded bacteriocin cluster, no bacteriocin biosynthesis was observed, possibly due to a 4-bp deletion at the beginning of the histidine kinase determinant abpK. The genome of L. salivarius CECT 5713 harbours two apparently complete prophages of 39.6 and 48 kbp. Upon induction, the 48-kbp prophage became liberated from the bacterial genome, but no DNA replication took place, which resulted in lysis of the cultures but not in phage progeny generation. The strain was sensitive to most antibiotics tested and no transmissible genes potentially involved in antibiotic resistance were detected. Finally, the genome of L. salivarius CECT 5713 contained four ORFs potentially involved in human molecular mimetism. Among them, protein 1230 was considered of particular relevance because of its similarity with dendritic cell-related proteins. Subsequently, in vitro assays revealed the ability of L. salivarius CECT 5713 to stimulate the maturation of immature dendritic cells and to inhibit the in vitro infectivity of HIV-1.


Asunto(s)
Lactobacillus/genética , Lactobacillus/fisiología , Leche Humana/microbiología , Antibacterianos/farmacología , Bacteriocinas/biosíntesis , Bacteriocinas/genética , Bacteriólisis , Farmacorresistencia Bacteriana , Genotipo , Humanos , Pruebas de Sensibilidad Microbiana , Fenotipo , Plásmidos , Profagos/genética , Profagos/crecimiento & desarrollo , Activación Viral
20.
J Bacteriol ; 193(19): 5605, 2011 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21914902

RESUMEN

Lactobacillus pentosus is the most prevalent lactic acid bacterium in Spanish-style green olive fermentations. Here we present the draft genome sequence of L. pentosus IG1, a bacteriocin-producing strain with biotechnological and probiotic properties isolated from this food fermentations.


Asunto(s)
Genoma Bacteriano/genética , Lactobacillus/genética , Fermentación , Datos de Secuencia Molecular , Olea/microbiología
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