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1.
Diagn Microbiol Infect Dis ; 107(4): 116077, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37742427

RESUMEN

Premature hospitalized neonates have a greater risk for candidemia, however, fungemia due to rare opportunistic yeasts have been recently reported and is associated with high mortality rates. We herein report the first case in Latin America of Lodderomyces elongisporus fungemia in a premature neonate with a fatal outcome.


Asunto(s)
Candidemia , Fungemia , Enfermedades del Recién Nacido , Saccharomycetales , Recién Nacido , Humanos , Fungemia/diagnóstico , Fungemia/tratamiento farmacológico , América Latina , Saccharomycetales/genética , Candidemia/tratamiento farmacológico , Levaduras , Antifúngicos/farmacología , Antifúngicos/uso terapéutico
2.
J Invertebr Pathol ; 199: 107939, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-37236421

RESUMEN

An epizootic caused by fungal pathogens occurred among Halyomorpha halys, brown marmorated stink bugs, while they were overwintering, with infections also occurring after overwintering. We report that one of the two pathogens responsible was Colletotrichum fioriniae (Marcelino & Gouli) Pennycook; a species well known as a plant pathogen and endophyte and which has only previously been reported naturally infecting elongate hemlock scales, Fiorinia externa. To prove pathogenicity, H. halys adults challenged with conidia died from infections and the fungus subsequently produced conidia externally on cadavers.


Asunto(s)
Colletotrichum , Heterópteros , Animales , Plantas , Cadáver
3.
Braz J Microbiol ; 54(1): 69-80, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36477756

RESUMEN

Clustered regularly interspaced short palindromic repeats (CRISPR) are a prokaryotic adaptive immune system that, through Cas proteins, promote the degradation of foreign nucleic acids such as phages and plasmids. We analyzed 10 genomes of Corynebacterium striatum clinical isolates from a public hospital in Rio de Janeiro, Brazil, the most emergent multidrug-resistant Corynebacterium species. All isolates were submitted to antimicrobial susceptibility testing. The occurrence and diversity of the CRISPR system were investigated by bioinformatics tools. Our analysis revealed that the isolates exhibited type I-E gene arrangements, and 3 more multidrug-resistant isolates, alternative type I-E gene arrangements, showing a divergent gene arrangement within the cas operon. Phylogenetic analysis of the cas1 gene of this type I-E CRISPR-Cas system alternative arrangement, termed here type I-E', showed a cluster in a distinct clade of the type I-E CRISPR-Cas system. The systems' guanine-cytosine (GC) content is lower than the genomic DNA's GC content, and mobile genetic elements were found in some isolates near the CRISPR-Cas system. Most CRISPR spacers are unknown indicating that there is a reservoir of unexplored corynebacteriophages and plasmids. Some spacers showed perfect homologies with phage and plasmid sequences. Intact phage regions were found in 3 of our isolates, ranging from 9.1 to 43.8 kb, with regions showing similarity to Rhodococcus and Corynebacterium phages. Our results may contribute to research about the CRISPR-Cas system diversity in C. striatum, where there are no published data to date.


Asunto(s)
Bacteriófagos , Sistemas CRISPR-Cas , Filogenia , Brasil , Corynebacterium , Bacteriófagos/genética
4.
Front Microbiol ; 12: 653107, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33815346

RESUMEN

The misuse of antibiotics is leading to the emergence of multidrug-resistant (MDR) bacteria, and in the absence of available treatments, this has become a major global threat. In the middle of the recent severe acute respiratory coronavirus 2 (SARS-CoV-2) pandemic, which has challenged the whole world, the emergence of MDR bacteria is increasing due to prophylactic administration of antibiotics to intensive care unit patients to prevent secondary bacterial infections. This is just an example underscoring the need to seek alternative treatments against MDR bacteria. To this end, phage therapy has been proposed as a promising tool. However, further research in the field is mandatory to assure safety protocols and to develop appropriate regulations for its use in clinics. This requires investing more in such non-conventional or alternative therapeutic approaches, to develop new treatment regimens capable of reducing the emergence of MDR and preventing future global public health concerns that could lead to incalculable human and economic losses.

5.
Am J Infect Control ; 49(6): 804-807, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-33485922

RESUMEN

BACKGROUND: Candida auris was first described in Japan in 2009 and has since been detected in over 40 countries. The yeast is concerning for multiple reasons, primarily: (1) challenges with accurate identification; (2) reported multidrug resistance; (3) published mortality rates of 30%-60%; and (4) persistence in the environment associated with human transmission. We report the emergence of a healthcare-associated cluster in the Greater Vancouver area in 2018 and describe the measures implemented to contain its transmission. METHODS: Cases were identified through passive and ring surveillance of affected wards. Positive isolates were sent to provincial and national reference laboratories for confirmation and genomic characterization. Extensive infection control measures were implemented immediately after the initial case was identified. RESULTS: Four cases were identified during the outbreak. In a 4-month period, over 700 swabs were collected in order to screen 180 contacts. Whole genome sequencing concluded that all isolates clustered together and belonged to the South Asian clade. No isolates harbored FKS gene mutations associated with resistance to echinocandins. Infection control measures, including surveillance, education, cleaning and/or disinfection, patient cohorting, isolation, and hand hygiene, effectively contained the outbreak; it was declared over within 2 months. CONCLUSIONS: The spread of C auris in healthcare facilities has not spared Canadian institutions. Our experience demonstrates that strict infection control measures combined with microbiological screening can effectively halt transmission in healthcare centers. The necessity of active prospective screening remains unclear.


Asunto(s)
Candida , Candidiasis , Antifúngicos/farmacología , Antifúngicos/uso terapéutico , Canadá/epidemiología , Candida/genética , Candidiasis/tratamiento farmacológico , Candidiasis/epidemiología , Brotes de Enfermedades , Humanos , Japón , Estudios Prospectivos
6.
J Clin Microbiol ; 59(2)2021 01 21.
Artículo en Inglés | MEDLINE | ID: mdl-33148703

RESUMEN

Vibrio vulnificus is a zoonotic pathogen that is spreading worldwide due to global warming. Lineage 3 (L3; formerly biotype 3) includes the strains of the species with the unique ability to cause fish farm-linked outbreaks of septicemia. The L3 strains emerged recently and are particularly virulent and difficult to identify. Here, we describe a newly developed PCR method based on a comparative genomic study useful for both rapid identification and epidemiological studies of this interesting emerging group. The comparative genomic analysis also revealed the presence of a genetic duplication in the L3 strains that could be related to the unique ability of this lineage to produce septicemia outbreaks.


Asunto(s)
Enfermedades de los Peces , Sepsis , Vibriosis , Vibrio vulnificus , Vibrio , Animales , Brotes de Enfermedades , Enfermedades de los Peces/epidemiología , Humanos , Sepsis/diagnóstico , Sepsis/epidemiología , Vibriosis/epidemiología , Vibrio vulnificus/genética
7.
Front Microbiol ; 11: 524, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32296407

RESUMEN

The molecular basis of the pathogenesis of the opportunistic invasive infections caused by isolates of the Gemella genus remains largely unknown. Moreover, inconsistencies in the current species assignation were detected after genome-level comparison of 16 public Gemella isolates. A literature search detected that, between the two most pathogenic species, Gemella morbillorum causes about twice the number of cases compared to Gemella haemolysans. These two species shared their mean diseases - sepsis and endocarditis - but differed in causing other syndromes. A number of well-known virulence factors were harbored by all species, such as a manganese transport/adhesin sharing 83% identity from oral endocarditis-causing streptococci. Likewise, all Gemellae carried the genes required for incorporating phosphorylcholine into their cell walls and encoded some choline-binding proteins. In contrast, other proteins were species-specific, which may justify the known epidemiological differences. G. haemolysans, but not G. morbillorum, harbor a gene cluster potentially encoding a polysaccharidic capsule. Species-specific surface determinants also included Rib and MucBP repeats, hemoglobin-binding NEAT domains, peptidases of C5a complement factor and domains that recognize extracellular matrix molecules exposed in damaged heart valves, such as collagen and fibronectin. Surface virulence determinants were associated with several taxonomically dispersed opportunistic genera of the oral microbiota, such as Granulicatella, Parvimonas, and Streptococcus, suggesting the existence of a horizontally transferrable gene reservoir in the oral environment, likely facilitated by close proximity in biofilms and ultimately linked to endocarditis. The identification of the Gemella virulence pool should be implemented in whole genome-based protocols to rationally predict the pathogenic potential in ongoing clinical infections caused by these poorly known bacterial pathogens.

8.
Int J Food Microbiol ; 319: 108495, 2020 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-31911211

RESUMEN

Bovine lactoferrin (bLF) is an iron-binding glycoprotein used in functional and therapeutic products due to its biological properties, the most important being its antimicrobial activity. In this study, hydrolysates of bovine lactoferrin (bLFH) obtained with pepsin, chymosin and microbial rennet were assayed against Cronobacter sakazakii (104 CFU/mL) in different media: phosphate buffered saline (PBS), bovine skim milk and whey, and reconstituted powdered infant formula (PIFM). The results obtained have shown that hydrolysis of bLF enhances its antibacterial activity against C. sakazakii. The three types of bLFH dissolved in PBS reduced C. sakazakii growth from a concentration of 0.1 mg/mL and inhibited it completely above 0.5 mg/mL, after 4 and 8 h of incubation at 37 °C. The three bLFH (1 and 2 mg/mL) did not show any antibacterial activity in skim milk, whey and reconstituted PIFM after 8 h of incubation at 37 °C. However, C. sakazakii growth was completely inhibited in whey when pepsin and chymosin bLFH (2 mg/mL) were combined with undigested bLF (2 mg/mL), after 8 h of incubation at 37 °C. On the other hand, the combination of any of the three hydrolysates with bLF showed very low activity in skim milk and practically no activity in reconstituted PIFM. Furthermore, the effect of temperature after reconstitution (4, 23 and 37 °C), on the antibacterial activity of bLF (2.5 and 5 mg/mL) in reconstituted PIFM contaminated with C. sakazakii (10-102 CFU/mL) was also investigated. bLF at 5 mg/mL significantly reduced (p < .05) the proliferation of C. sakazakii in reconstituted PIFM at 37 °C until 2 h. C. sakazakii did not grow at 4 °C for 6 days in reconstituted PIFM with or without bLF. The effect of microwave heating (450, 550 and 650 W for 5, 10 and 15 s) on the antibacterial activity and stability of bLF (2.5 mg/mL) in reconstituted PIFM contaminated with C. sakazakii (10-102 CFU/mL) was also studied. The antibacterial activity of bLF was maintained after treatments at 450 and 550 W for 5 s, which kept 94 and 89% of bLF immunoreactivity, respectively. Moreover, microwave treatments of reconstituted PIFM with or without bLF, at 650 W for 5 s, and at 450, 550 and 650 W for 10 and 15 s, completely inactivated C. sakazakii.


Asunto(s)
Antibacterianos/farmacología , Cronobacter sakazakii/efectos de los fármacos , Lactoferrina/farmacología , Leche/microbiología , Animales , Bovinos , Quimosina/metabolismo , Recuento de Colonia Microbiana , Cronobacter sakazakii/crecimiento & desarrollo , Humanos , Hidrólisis , Lactante , Fórmulas Infantiles/microbiología , Microondas , Pepsina A/metabolismo , Temperatura
9.
Hig. aliment ; 32(284/285): 20-25, out. 30, 2018. ilus
Artículo en Portugués | LILACS | ID: biblio-965460

RESUMEN

A presença de Enterobacteriaceae indica a qualidade higiênica dos produtos alimentícios. Dentro do grupo das bactérias que fazem parte dessa família está Hafnia alvei. Estudo bibliométrico é uma importante ferramenta metodológica de revisão sistemática para reunir e sintetizar as diversas informações que surgem sobre um tema, inclusive sobre os estudos relativos a micro- -organismos. O objetivo deste trabalho foi realizar um estudo bibliométrico sobre este agente. Para tal foi utilizada a base de dados Web of Science usando o nome do agente e o termo food para a busca e limitando a pesquisa entre 2007 e 2017. As informações principais dos documentos foram registradas, bem como a característica principal das publicações sobre o tema. Foram encontrados 42 artigos científicos que contemplaram os termos de busca. A maioria das publicações ocorreu em países e períodos onde ocorreram surtos alimentares e há uma grande pesquisa relacionada à genoma e resistência a antimicrobianos. Avalia-se que ainda existem várias oportunidades de pesquisa sobre os micro-organismos, visto que eles são pouco estudados, principalmente em nosso país.


The presence of Enterobacteriaceae indicates the hygienic quality of food products. As a part of this family, there is an emergent pathogen: Hafnia alvei. Bibliometrics appears as an important tool to gather and synthesize all the information that appears about the new microorganisms. The objective of this paper is to perform a systematic review of literature with bibliometric analysis in order to know the evolution of these bacteria and seek opportunities for new research. To do this, the Web of Science database was searched, individually searching for Hafnia alvei refining for "food". The articles found were analyzed from the annual production, countries, institutions, areas of knowledge, authors who produced the most and periodicals most used. A total of 42 articles were selected for Hafnia alvei. Most publications have occurred in countries and periods where there have been food outbreaks and there is great genomerelated research and antimicrobial resistance. It is evaluated that there are still several research opportunities on microorganisms, since they are little studied, mainly in our country.


Asunto(s)
Bibliometría , Hafnia alvei , Enterobacteriaceae , Microbiología , Noxas , Control de Calidad , Bacterias , Producción de Alimentos , Revisión
10.
BMC Evol Biol ; 18(1): 93, 2018 07 05.
Artículo en Inglés | MEDLINE | ID: mdl-29973156

RESUMEN

BACKGROUND: Outbreaks caused by asexual lineages of fungal and oomycete pathogens are a continuing threat to crops, wild animals and natural ecosystems (Fisher MC, Henk DA, Briggs CJ, Brownstein JS, Madoff LC, McCraw SL, Gurr SJ, Nature 484:186-194, 2012; Kupferschmidt K, Science 337:636-638, 2012). However, the mechanisms underlying genome evolution and phenotypic plasticity in asexual eukaryotic microbes remain poorly understood (Seidl MF, Thomma BP, BioEssays 36:335-345, 2014). Ever since the 19th century Irish famine, the oomycete Phytophthora infestans has caused recurrent outbreaks on potato and tomato crops that have been primarily caused by the successive rise and migration of pandemic asexual lineages (Goodwin SB, Cohen BA, Fry WE, Proc Natl Acad Sci USA 91:11591-11595, 1994; Yoshida K, Burbano HA, Krause J, Thines M, Weigel D, Kamoun S, PLoS Pathog 10:e1004028, 2014; Yoshida K, Schuenemann VJ, Cano LM, Pais M, Mishra B, Sharma R, Lanz C, Martin FN, Kamoun S, Krause J, et al. eLife 2:e00731, 2013; Cooke DEL, Cano LM, Raffaele S, Bain RA, Cooke LR, Etherington GJ, Deahl KL, Farrer RA, Gilroy EM, Goss EM, et al. PLoS Pathog 8:e1002940, 2012). However, the dynamics of genome evolution within these clonal lineages have not been determined. The objective of this study was to use a comparative genomics and transcriptomics approach to determine the molecular mechanisms that underpin phenotypic variation within a clonal lineage of P. infestans. RESULTS: Here, we reveal patterns of genomic and gene expression variation within a P. infestans asexual lineage by comparing strains belonging to the South American EC-1 clone that has dominated Andean populations since the 1990s (Yoshida K, Burbano HA, Krause J, Thines M, Weigel D, Kamoun S, PLoS Pathog 10e1004028, 2014; Yoshida K, Schuenemann VJ, Cano LM, Pais M, Mishra B, Sharma R, Lanz C, Martin FN, Kamoun S, Krause J, et al. eLife 2:e00731, 2013; Delgado RA, Monteros-Altamirano AR, Li Y, Visser RGF, van der Lee TAJ, Vosman B, Plant Pathol 62:1081-1088, 2013; Forbes GA, Escobar XC, Ayala CC, Revelo J, Ordonez ME, Fry BA, Doucett K, Fry WE, Phytopathology 87:375-380, 1997; Oyarzun PJ, Pozo A, Ordonez ME, Doucett K, Forbes GA, Phytopathology 88:265-271, 1998). We detected numerous examples of structural variation, nucleotide polymorphisms and loss of heterozygosity within the EC-1 clone. Remarkably, 17 genes are not expressed in one of the two EC-1 isolates despite apparent absence of sequence polymorphisms. Among these, silencing of an effector gene was associated with evasion of disease resistance conferred by a potato immune receptor. CONCLUSIONS: Our findings highlight the molecular changes underpinning the exceptional genetic and phenotypic plasticity associated with host adaptation in a pandemic clonal lineage of a eukaryotic plant pathogen. We observed that the asexual P. infestans lineage EC-1 can exhibit phenotypic plasticity in the absence of apparent genetic mutations resulting in virulence on a potato carrying the Rpi-vnt1.1 gene. Such variant alleles may be epialleles that arose through epigenetic changes in the underlying genes.


Asunto(s)
Interacciones Huésped-Patógeno/genética , Evasión Inmune/genética , Inmunidad/genética , Phytophthora infestans/genética , Enfermedades de las Plantas/inmunología , Polimorfismo Genético , Solanum tuberosum/inmunología , Solanum tuberosum/microbiología , Regulación de la Expresión Génica , Filogenia , Phytophthora infestans/patogenicidad , Enfermedades de las Plantas/microbiología , Virulencia
11.
Adv Appl Microbiol ; 103: 49-101, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29914659

RESUMEN

Being able to track bacterial pathogens is essential for epidemiological purposes as well as monitoring in-house production facilities. Common bacterial pathogens, such as Salmonella serovars, are already been well defined, and their detection methods are very advanced. However, this will not be the case for emergent bacterial pathogens, as was the case for Cronobacter. The clinical significance of the organism is due to its association with rare sporadic infections in adults, and severe life-threatening outbreaks of necrotizing enterocolitis and meningitis in newborn babies. The main recognized route of infection being through the consumption of contaminated reconstituted powdered infant formula. Key to the advances in being able to track this organism during formula production and outbreaks in neonatal intensive care units has been the use of DNA sequence-based methods, and most recently those which profile whole-genome sequences. This chapter considers how the latest DNA sequence-based methods in genotyping Cronobacter serve as a model for analyzing emergent bacterial pathogens in the future. The methods considered will initially highlight the limitations of phenotyping, then advance from the DNA probe-based methods for serotyping through to DNA sequence-based methods, especially multilocus sequence typing which is supported by an open access database. Finally the development of typing methods based on whole-genomes sequences, CRISPR-cas array profiling and SNP analysis, will be covered. The overall perspective is that emergent pathogens need to be investigated with the most advanced methods in order for robust and reliable control measures to be adopted.


Asunto(s)
Cronobacter/clasificación , Cronobacter/aislamiento & purificación , Enfermedades Transmitidas por los Alimentos/epidemiología , Enfermedades Transmitidas por los Alimentos/microbiología , Infecciones por Bacterias Gramnegativas/epidemiología , Infecciones por Bacterias Gramnegativas/microbiología , Tipificación Molecular/métodos , Técnicas de Tipificación Bacteriana , Enterocolitis Necrotizante/epidemiología , Enterocolitis Necrotizante/microbiología , Humanos , Meningitis Bacterianas/epidemiología , Meningitis Bacterianas/microbiología , Epidemiología Molecular/métodos
12.
Front Microbiol ; 6: 272, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25904905

RESUMEN

Gastric infections caused by the environmentally transmitted pathogen, Vibrio parahaemolyticus, have increased over the last two decades, including in many parts of the United States (US). However, until recently, infections linked to shellfish from the cool northeastern US waters were rare. Cases have risen in the Northeast, consistent with changes in local V. parahaemolyticus populations toward greater abundance or a shift in constituent pathogens. We examined 94 clinical isolates from a period of increasing disease in the region and compared them to 200 environmental counterparts to identify resident and non-indigenous lineages and to gain insight into the emergence of pathogenic types. Genotyping and multi-locus sequence analysis (MLSA) of clinical isolates collected from 2010 to 2013 in Massachusetts, New Hampshire, and Maine revealed their polyphyletic nature. Although 80% of the clinical isolates harbored the trh hemolysin either alone or with tdh, and were urease positive, 14% harbored neither hemolysin exposing a limitation for these traits in pathogen detection. Resident sequence type (ST) 631 strains caused seven infections, and show a relatively recent history of recombination with other clinical and environmental lineages present in the region. ST34 and ST674 strains were each linked to a single infection and these strain types were also identified from the environment as isolates harboring hemolysin genes. Forty-two ST36 isolates were identified from the clinical collection, consistent with reports that this strain type caused a rise in regional infections starting in 2012. Whole-genome phylogenies that included three ST36 outbreak isolates traced to at least two local sources demonstrated that the US Atlantic coastal population of this strain type was indeed derived from the Pacific population. This study lays the foundation for understanding dynamics within natural populations associated with emergence and invasion of pathogenic strain types in the region.

13.
Rev Iberoam Micol ; 32(4): 257-60, 2015.
Artículo en Español | MEDLINE | ID: mdl-25579090

RESUMEN

BACKGROUND: Invasive fungal infection is an important cause of morbimortality in patients with severe burns. The advances in burn care therapy have considerably extended the survival of seriously burned patients, exposing them to infectious complications, notably fungal infections, with increased recognition of invasive infections caused by Candida species. However, some opportunistic fungi, like Trichosporon asahii, have emerged as important causes of nosocomial infection. CASE REPORT: A case of nosocomial infection due to T. asahii in a severely ill burned patient successfully treated with voriconazole is presented. The management of invasive fungal infections in burned patients, from diagnosis to selection of the therapeutic protocol, is often a challenge. Early diagnosis and treatment are associated with a better prognosis. In this case report, current treatment options are discussed, and a review of previously published cases is presented. CONCLUSIONS: Due to the difficulty in the diagnosis of invasive mycoses and their high associated mortality rates, it is advisable to keep a high degree of clinical suspicion of trichosporonosis in susceptible patients, including burned patients. The isolation of T. asahii in clinical specimens of this type of host must raise clinical alert, since it may precede an invasive infection.


Asunto(s)
Quemaduras/complicaciones , Infección Hospitalaria/microbiología , Infecciones Oportunistas/microbiología , Trichosporon/aislamiento & purificación , Tricosporonosis/microbiología , Infección de Heridas/microbiología , Accidentes de Trabajo , Antifúngicos/uso terapéutico , Quemaduras/microbiología , Candidiasis/complicaciones , Caspofungina , Cateterismo Venoso Central , Coinfección , Infección Hospitalaria/tratamiento farmacológico , Infección Hospitalaria/etiología , Oído Externo/lesiones , Oído Externo/microbiología , Equinocandinas/uso terapéutico , Infecciones por Enterobacteriaceae/complicaciones , Femenino , Humanos , Huésped Inmunocomprometido , Lipopéptidos , Persona de Mediana Edad , Morganella morganii/aislamiento & purificación , Infecciones Oportunistas/tratamiento farmacológico , Infecciones Oportunistas/etiología , Respiración Artificial , Choque Séptico/etiología , Tricosporonosis/diagnóstico , Tricosporonosis/tratamiento farmacológico , Tricosporonosis/etiología , Voriconazol/uso terapéutico , Infección de Heridas/tratamiento farmacológico
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