Primer aislamiento de Sporothrix brasiliensis en un caso humano de esporotricosis en Chile. Un hongo emergente y preocupante / First isolation of Sporothrix brasiliensis in a human case of sporotrichosis in Chile. An emerging and worrisome fungus

Se describe el aislamiento de Sporothrix brasiliensis desde una biopsia de piel de un caso humano de esporotricosis linfocutánea, en la región de Valparaíso, Chile. Esta especie es la más virulenta del género y es de transmisión zoonótica, desde los gatos a los humanos. Hasta ahora, solo se había publicado un brote por esta especie en gatos domésticos y asilvestrados en el extremo sur de Chile, por lo que este aislamiento, en una mujer residente de un sector densamente poblado de la Región de Valparaíso, constituye una preocupación por su eventual diseminación hacia otros gatos y la población general.

The isolation of Sporothrix brasiliensis from a skin biopsy of a human case of lymphocutaneous sporotrichosis in the region of Valparaíso, Chile is described. This species is the most virulent of the genus and is zoonotic in transmission from cats to humans. Until now, only one outbreak of this species has been published in domestic and feral cats in the extreme south of Chile, so this isolation in a woman residing in a densely populated sector of the fifth region is a concern for its eventual spread to other cats and the general population.

Phylogenetic analysis of the first four SARS-CoV-2 cases in Chile.

The current pandemic caused by the new coronavirus is a worldwide public health concern. To aboard this emergency, and like never before, scientific groups around the world have been working in a fast and coordinated way to get the maximum of information about this virus when it has been almost 3 months since the first cases were detected in Wuhan province in China. The complete genome sequences of around 450 isolates are available, and studies about similarities and differences among them and with the close related viruses that caused similar epidemics in this century. In this work, we studied the complete genome of the first four cases of the new coronavirus disease in Chile, from patients who traveled to Europe and Southeast Asia. Our findings reveal at least two different viral variants entries to Chilean territory, coming from Europe and Asia. We also sub-classified the isolates into variants according to punctual mutations in the genome. Our work contributes to global information about transmission dynamics and the importance to take control measures to stop the spread of the infection.

Analysis of Mycobacterium tuberculosis Genotypic Lineage Distribution in Chile and Neighboring Countries.

Tuberculosis (TB), caused by the pathogen Mycobacterium tuberculosis (MTB), remains a disease of high importance to global public health. Studies into the population structure of MTB have become vital to monitoring possible outbreaks and also to develop strategies regarding disease control. Although Chile has a low incidence of MTB, the current rates of migration have the potential to change this scenario. We collected and analyzed a total of 458 M. tuberculosis isolates (1 isolate per patient) originating from all 15 regions of Chile. The isolates were genotyped using the spoligotyping method and the data obtained were analyzed and compared with the SITVIT2 database. A total of 169 different patterns were identified, of which, 119 patterns (408 strains) corresponded to Spoligotype International Types (SITs) and 50 patterns corresponded to orphan strains. The most abundantly represented SITs/lineages were: SIT53/T1 (11.57%), SIT33/LAM3 (9.6%), SIT42/LAM9 (9.39%), SIT50/H3 (5.9%), SIT37/T3 (5%); analysis of the spoligotyping minimum spanning tree as well as spoligoforest were suggestive of a recent expansion of SIT42, SIT50 and SIT37; all of which potentially evolved from SIT53. The most abundantly represented lineages were LAM (40.6%), T (34.1%) and Haarlem (13.5%). LAM was more prevalent in the Santiago (43.6%) and Concepción (44.1%) isolates, rather than the Iquique (29.4%) strains. The proportion of X lineage was appreciably higher in Iquique and Concepción (11.7% in both) as compared to Santiago (1.6%). Global analysis of MTB lineage distribution in Chile versus neighboring countries showed that evolutionary recent lineages (LAM, T and Haarlem) accounted together for 88.2% of isolates in Chile, a pattern which mirrored MTB lineage distribution in neighboring countries (n = 7378 isolates recorded in SITVIT2 database for Peru, Brazil, Paraguay, and Argentina; and published studies), highlighting epidemiological advantage of Euro-American lineages in this region. Finally, we also observed exclusive emergence of patterns SIT4014/X1 and SIT4015 (unknown lineage signature) that have hitherto been found exclusively in Chile, indicating that conditions specific to Chile, along with the unique genetic makeup of the Chilean population, might have allowed for a possible co-evolution leading to the success of these emerging genotypes.

Novel nonsense mutation in the katA gene of a catalase-negative Staphylococcus aureus strain

Abstract We report the first description of a rare catalase-negative strain of Staphylococcus aureus in Chile. This new variant was isolated from blood and synovial tissue samples of a pediatric patient. Sequencing analysis revealed that this catalase-negative strain is related to ST10 strain, which has earlier been described in relation to S. aureus carriers. Interestingly, sequence analysis of the catalase gene katA revealed presence of a novel nonsense mutation that causes premature translational truncation of the C-terminus of the enzyme leading to a loss of 222 amino acids. Our study suggests that loss of catalase activity in this rare catalase-negative Chilean strain is due to this novel nonsense mutation in the katA gene, which truncates the enzyme to just 283 amino acids.

Novel nonsense mutation in the katA gene of a catalase-negative Staphylococcus aureus strain.

We report the first description of a rare catalase-negative strain of Staphylococcus aureus in Chile. This new variant was isolated from blood and synovial tissue samples of a pediatric patient. Sequencing analysis revealed that this catalase-negative strain is related to ST10 strain, which has earlier been described in relation to S. aureus carriers. Interestingly, sequence analysis of the catalase gene katA revealed presence of a novel nonsense mutation that causes premature translational truncation of the C-terminus of the enzyme leading to a loss of 222 amino acids. Our study suggests that loss of catalase activity in this rare catalase-negative Chilean strain is due to this novel nonsense mutation in the katA gene, which truncates the enzyme to just 283 amino acids.

[Genetic characterization of the virus causing H1N1 influenza pandemic in Chile: analysis of the first detected cases]. / Inicio del brote de Influenza A (H1N1) pandémica en Chile: caracterización genética de los primeros casos detectados.

BACKGROUND: Following the announcement of the Influenza A(H1N1) pandemic by the World Health Organization in April 2009, a surveillance program was carried out in Chile to detect the introduction of the virus in the country and to monitor its propagation and impact. AIM: To describe the onset of the outbreak and the genetic characterization of the pandemic H1N1 influenza virus in the first detected cases in Chile. MATERIAL AND METHODS: Analysis of18 clinical samples coming from suspicious patients, received in a National Reference Laboratory. RNA reverse transcription and real time influenza gene DNA amplification was carried out in a 7500 Fast and Step One Real Time PCR Systems of Applied Biosystems and MxPro-Mx3000P thermocycler from Stratagene. Super Script III Platinum One-Step Quantitative RT-PCR was used. RESULTS: The virus was first detected in three persons returning from the Dominican Republic via Panamá and a child from the east zone of Santiago. Genetic characterization of the virus showed that the child was infected by a different variant of the pandemic virus than the three persons returning from the Caribbean. CONCLUSIONS: The onset of the Influenza outbreak in Chile apparently carne from two different epidemiological groups. The spread of the virus detected in the voyagers was limited immediately However the virus of the fourth case was found in different regions of Chile.

[Detection of genes associated with drug resistance in Mycobacterium tuberculosis strains isolated in Chile]. / Detección de mutaciones asociadas a cepas multidrogo resistente de Mycobacterium tuberculosis en Chile.

BACKGROUND: The incidence of acquired resistance to antituberculous drugs of Mycobacterium tuberculosis in Chile is approximately 23%. AIM: To analyze the mutations associated with drug resistance in drug resistant strains of Mycobacterium tuberculosis. MATERIAL AND METHODS: In 28 drug resistant Mycobacterium tuberculosis strains isolated in Chile, genes leading to drug resistance were studied. DNA was amplified by polymerase chain reaction (PCR) and sequencing was carried out using the ABI PRISM big dye terminator cycle sequencing ready reaction kit. RESULTS: In rifampicin-resistant strains, the mutations in rpoß gene were in the codons S531W/L (56%), D516Y (16%) and D516V (16%). The predominant mutation in katG gene was in the codon S315L (73%) in isoniazid-resistant strains. The mutation S95T was found in the 71% of ciprofloxacin resistant strains. Only one ethambutol resistant strain had the M306I mutation. Three unreported mutations in katG were identified. CONCLUSIONS: Drug resistance associated mutations of Mycobacterium tuberculosis isolated in Chile were similar to those reported abroad.

Inicio del brote de Influenza A (H1N1) pandémica en Chile: caracterización genética de los primeros casos detectados / Genetic characterization of the virus causing H1N1 influenza pandemic in Chile: Analysis of the first detected cases

Background: Following the announcement of the Influenza A(H1N1) pandemic by the World Health Organization in April 2009, a surveillance program was carried out in Chile to detect the introduction of the virus in the country and to monitor its propagation and impact. Aim: To describe the onset of the outbreak and the genetic characterization of the pandemic H1N1 influenza virus in the first detected cases in Chile. Material and Methods: Analysis of18 clinical samples coming from suspicious patients, received in a National Reference Laboratory. RNA reverse transcription and real time influenza gene DNA amplification was carried out in a 7500 Fast and Step One Real Time PCR Systems of Applied Biosystems and MxPro-Mx3000P thermocycler from Stratagene. Super Script III Platinum One-Step Quantitative RT-PCR was used. Results: The virus was first detected in three persons returning from the Dominican Republic via Panamá and a child from the east zone of Santiago. Genetic characterization of the virus showed that the child was infected by a different variant of the pandemic virus than the three persons returning from the Caribbean. Conclusions: The onset of the Influenza outbreak in Chile apparently carne from two different epidemiological groups. The spread of the virus detected in the voyagers was limited immediately However the virus of the fourth case was found in different regions of Chile.

Detección de mutaciones asociadas a cepas multidrogo resistente de Mycobacterium tuberculosis en Chile / Detection of genes associated with drug resistance in Mycobacterium tuberculosis strains isolated in Chile

Background: The incidence of acquired resistance to antituberculous drugs of Mycobacterium tuberculosis in Chile is approximately 23 percent. Aim: To analyze the mutations associated with drug resistance in drug resistant strains of Mycobacterium tuberculosis. Material and Methods: In 28 drug resistant Mycobacterium tuberculosis strains isolated in Chile, genes leading to drug resistance were studied. DNA was amplifed by polymerase chain reaction (PCR) and sequencing was carried out using the ABI PRISM big dye terminator cycle sequencing ready reaction kit. Results: In rifampicin-resistant strains, the mutations in rpoβ gene were in the codons S531W/L (56 percent), D516Y (16 percent) and D516V (16 percent). The predominant mutation in katG gene was in the codon S315L (73 percent) in isoniazid-resistant strains. The mutation S95T was found in the 71 percent of ciprofoxacin resistant strains. Only one ethambutol resistant strain had the M306I mutation. Three unreported mutations in katG were identifed. Conclusions: Drug resistance associated mutations of Mycobacterium tuberculosis isolated in Chile were similar to those reported abroad.

[Molecular subtyping of Salmonella enterica serotype Enteritidis in a post epidemic period]. / Subtipificación molecular de Salmonella entérica serotipo Enteritidis en el período post epidémico.

BACKGROUND: In the last two decades, Salmonella enterica serotype Enteritidis has become one of the main agents causing food borne diseases worldwide. This agent is transmitted mainly by contaminated meat and poultry. AIM: To determine the genetic subtypes of Salmonella enterica serotype Enteritidis, circulating in Chile between 2001 and 2003, a post epidemic period. MATERIAL AND METHODS: One hundred ninety three isolates coming from human samples, prepared foods and animal products for human consumption, were analyzed by pulsed field electrophoresis, using PulseNet standardized protocol. RESULTS: Thirteen subtypes of Salmonella enterica serotype Enteritidis were identified, that had between 0 and 13 bands. A predominant subtype was identified in 172 strains (88%) that came from human isolates, prepared foods and animal products for human consumption. Other four subtypes, found in prepared foods and animal products for human consumption, were also found in human isolates. Most subtypes were tightly interrelated Subtypes II, VIII and XI were also found in the 1994 epidemic. CONCLUSIONS: Subtyping of bacterial strains by pulsed field electrophoresis is useful for the surveillance of food borne diseases.

Subtipificación molecular de Salmonella entérica serotipo Enteritidis en el período post epidémico / Molecular subtyping of Salmonella enterica serotype Enteritidis in a post epidemic period

Background: In the last two decades, Salmonella enterica serotype Enteritidis has become one of the main agents causing food borne diseases worldwide. This agent is transmitted mainly by contaminated meat and poultry. Aim: To determine the genetic subtypes of Salmonella enterica serotype Enteritidis, circulating in Chile between 2001 and 2003, a post epidemc period. Material and methods: One hundred ninety three isolates coming from human samples, prepared foods and animal products for human consumption, were analyzed bypulsed field electrophoresis, using PulseNet standardized protocol. Results: Thirteen subtypes of Salmonella enterica serotype Enteritidis were identified, that had between 0 and 13 bands. A predominant subtype was identified in 172 strains (88%) that carne from human isolates, prepared foods and animal producís for human consumption. Other four subtypes, found in prepared foods and animal products for human consumption, were also found in human isolales. Most subtypes were lighlly inlerrelaled Subtypes II, VIII and XI were also found in the 1994 epidemic. Conclusions: Subtyping of baclerial strains by pulsed field electrophoresis is useful for the surveillance of food borne diseases.

Regulatory T cells are locally induced during intravaginal infection of mice with Neisseria gonorrhoeae.

Neisseria gonorrhoeae is a gram-negative diplococcus that in human beings produces gonorrhea. Much clinical evidence has led to the conclusion that gonococcus has important mechanisms to evade host immune functions; however, these mechanisms are only now beginning to be elucidated. In this study, we determined that the BALB/c mouse is a good animal model to study gonococcus infection and examined the immune response against the bacteria. We determined that after intravaginal inoculation of mice with Neisseria gonorrhoeae, the bacteria reached and invaded the upper female reproductive tissues and elicited a T-cell-specific immune response associated with a very weak humoral response, altogether resembling gonococcus infection and disease in women. Remarkably, in the draining lymph nodes of the genital tracts of infected mice, we found an increase of regulatory T lymphocytes, namely, transforming growth factor beta1-positive CD4(+) T cells and CD4(+) CD25(+) Foxp3(+) T cells. Altogether, results indicate that N. gonorrhoeae induces regulatory T cells, which might be related to the local survival of the pathogen and the establishment of a chronic asymptomatic infection.