RESUMEN
Previous molecular studies have shown that Candida africana corresponds to the clade 13 of Candia albicans. It has been mostly involved in vulvovaginal candidiasis worldwide but few data exist in South America. The aim of our study was to investigate the prevalence of C. africana in women living in French Guiana. For this, we first set up a fluorescent-intercalating-dye-real time Polymerase Chain Reaction (PCR) targeting the hyphal wall protein 1 gene. The test was applied to 212 C. albicans isolates collected from May to August 2019 from vaginal swabs, allowing the identification of six women harboring C. africana (eight isolates). The in vitro susceptibility of these eight isolates to six antifungal drugs was also evaluated. No demographics or clinical-specific features could be demonstrated. Genetic diversity of those isolates was analyzed through multilocus sequence typing and showed that diploid sequence type 182 was predominant (n = 6) and allowed the report of a new diploid sequence type.
Candida africana, the clade 13 of C. albicans, is characterized by specific genetic and phenotypic traits. Using a new molecular technique, we report a high prevalence of C. africana in vaginal swabs from patients living in French Guiana. The worldwide predominant genotype was detected in all but one patient.
Asunto(s)
Candida , Candidiasis Vulvovaginal , Femenino , Humanos , Guyana Francesa/epidemiología , Epidemiología Molecular , Pruebas de Sensibilidad Microbiana/veterinaria , Candidiasis Vulvovaginal/epidemiología , Candidiasis Vulvovaginal/microbiología , Candidiasis Vulvovaginal/veterinaria , Vagina/microbiología , Antifúngicos , Candida albicansRESUMEN
Streptococcus pneumoniae or pneumococcus (PN) is a major causative agent of bacterial meningitis with high mortality in young infants and elderly people worldwide. The mechanism underlying PN crossing of the blood brain barrier (BBB) and specifically, the role of non-endothelial cells of the neurovascular unit that control the BBB function, remains poorly understood. Here, we show that the astroglial connexin 43 (aCx43), a major gap junctional component expressed in astrocytes, plays a predominant role during PN meningitis. Following intravenous PN challenge, mice deficient for aCx43 developed milder symptoms and showed severely reduced bacterial counts in the brain. Immunofluorescence analysis of brain slices indicated that PN induces the aCx43-dependent destruction of the network of glial fibrillary acid protein (GFAP), an intermediate filament protein specifically expressed in astrocytes and up-regulated in response to brain injury. PN also induced nuclear shrinkage in astrocytes associated with the loss of BBB integrity, bacterial translocation across endothelial vessels and replication in the brain cortex. We found that aCx4-dependent astrocyte damages could be recapitulated using in vitro cultured cells upon challenge with wild-type PN but not with a ply mutant deficient for the pore-forming toxin pneumolysin (Ply). Consistently, we showed that purified Ply requires Cx43 to promote host cell plasma membrane permeabilization in a process involving the Cx43-dependent release of extracellular ATP and prolonged increase of cytosolic Ca2+ in host cells. These results point to a critical role for astrocytes during PN meningitis and suggest that the cytolytic activity of the major virulence factor Ply at concentrations relevant to bacterial infection requires co-opting of connexin plasma membrane channels.
Asunto(s)
Astrocitos/metabolismo , Conexina 43/metabolismo , Meningitis Neumocócica , Estreptolisinas/metabolismo , Animales , Proteínas Bacterianas/metabolismo , Ratones , Ratones Endogámicos C57BL , Streptococcus pneumoniae/metabolismo , Streptococcus pneumoniae/patogenicidad , Virulencia/fisiología , Factores de Virulencia/metabolismoRESUMEN
OBJECTIVES: There is an urgent need for accurate and fast diagnostic tests to identify MDR bacteria. Here, we evaluated an immunochromatographic assay (the OXA-48 K-SeT assay) to detect OXA-48-like carbapenemase-producing Enterobacteriaceae from culture colonies. METHODS: One hundred and sixty-one collection isolates with characterized ß-lactamase content and 185 non-duplicate consecutive clinical isolates referred to the Associated French National Reference Center between 15 February and 15 March 2015 were used to evaluate the OXA-48 K-SeT assay. Among these 346 isolates, 100 were OXA-48-like carbapenemase producers, 3 were OXA-48-like producers lacking carbapenemase activity and 243 were ESBL, AmpC, oxacillinase and/or non-OXA-48 carbapenemase producers. RESULTS: All 100 OXA-48-like carbapenemase producers were correctly detected by the OXA-48 K-SeT assay, including OXA-48 (nâ=â73), OXA-181 (nâ=â18), OXA-162 (nâ=â1), OXA-204 (nâ=â4), OXA-232 (nâ=â2) and OXA-244 (nâ=â2) variants. The three OXA-48 variants lacking carbapenemase activity, OXA-163 (nâ=â2) and OXA-405 (nâ=â1), were not detected. All non-OXA-48 producers gave a negative result with the OXA-48 K-SeT assay. No cross-reaction was evidenced with the carbapenemases (VIM, IMP, NDM and KPC), ESBLs (TEM, SHV and CTX-M), AmpCs (CMY-2, DHA-2 and ACC-1) and oxacillinases (OXA-1, -2, -9 and -10). Overall, the sensitivity and specificity of the assay were 100% for OXA-48-like carbapenemase detection. CONCLUSIONS: The OXA-48 K-SeT assay was efficient, rapid and easy to implement in the routine workflow of a clinical microbiology laboratory for the confirmation of OXA-48-like carbapenemase-producing Enterobacteriaceae. It could complete the existing panel of tests available for the confirmation of OXA-48-like carbapenemases, especially in countries with high OXA-48 prevalence.
Asunto(s)
Proteínas Bacterianas/análisis , Técnicas Bacteriológicas/métodos , Cromatografía de Afinidad/métodos , Pruebas Diagnósticas de Rutina/métodos , Enterobacteriaceae/enzimología , beta-Lactamasas/análisis , Enterobacteriaceae/aislamiento & purificación , Infecciones por Enterobacteriaceae/microbiología , Humanos , Estudios Prospectivos , Factores de TiempoRESUMEN
OBJECTIVES: Few and small studies previously examined chest CT-scan characteristics of Coxiella burnetii (Cb) community-acquired pneumonia (CAP). Larger studies are needed to guide physicians towards diagnosis of Q fever in case of pneumonia. METHODS: We conducted a single-center retrospective observational study between 2013 and 2017. All patients with Cb or Streptococcus pneumoniae (Sp) CAP who had a chest CT-scan on admission at Cayenne Hospital (French Guiana) were included. Chest CT-scan were all analyzed by the same expert radiologist. RESULTS: We included 75 patients with Cb CAP and 36 with Sp CAP. Fifty-nine percent of all patients were men (n = 66) and median age was 52 [IQR = 38-62]. Chest CT-scans of Cb CAP patients revealed 67 alveolar condensations (89 %), 52 ground-glass opacities (69 %), 30 cases of lymphadenopathy(ies) (40 %) and 25 pleural effusions (33 %). Parenchyma lesions caused by Cb were predominantly unilateral (67 %). We found high numbers of alveolar condensations in both Cb and Sp CAP (89 % and 75 %; respectively), but the presence of ground-glass opacities was significantly associated with Cb CAP (69 % versus 30 %; p < 0.01). Cb CAP were associated with more lymphadenopathies (40 % vs 17 %; p = 0.01) while Sp CAP showed more bronchial thickening (19 % versus 3 %; p < 0.01) and (micro)nodule(s) ≤1 cm (25 % vs 3 %, p < 0.01). CONCLUSIONS: This large study shows that the most typical aspect of chest CT-scan in case of Cb CAP in French Guiana is a unilateral alveolar consolidation associated with ground glass opacities and lymphadenopathies. C. burnetti and S. pneumoniae both most often cause alveolar consolidations, but present some significantly different CT-scan patterns. This could help physicians through therapeutic choices.
Asunto(s)
Infecciones Comunitarias Adquiridas , Coxiella burnetii , Linfadenopatía , Neumonía , Fiebre Q , Masculino , Humanos , Persona de Mediana Edad , Femenino , Streptococcus pneumoniae , Fiebre Q/diagnóstico por imagen , Fiebre Q/epidemiología , Fiebre Q/etiología , Estudios Transversales , Guyana Francesa/epidemiología , Tomografía Computarizada por Rayos X/efectos adversos , Tomografía Computarizada por Rayos X/métodos , Estudios Retrospectivos , Linfadenopatía/diagnóstico por imagen , Infecciones Comunitarias Adquiridas/diagnóstico por imagenRESUMEN
Antimicrobial resistance (AMR) in the community is increasing worldwide. We aimed to assess AMR trends in Escherichia coli from the community urine isolates in French Amazonia. We conducted a retrospective study from January 2016 to December 2022 in the Cayenne General Hospital microbiology laboratory (French Guiana). It included all urine samples positive for E. coli collected from adult outpatients. During the study period, 3,443 urinalyses positive for E. coli were studied. In 46% of cases, patients were women. In 64.4% of cases, E. coli were ß-lactamase producers. The most frequently diagnosed resistance mechanisms were penicillinase production and sparing third-generation cephalosporins. Isolated E. coli were extended-spectrum ß-lactamase (ESBL) producers in 6.1% of cases. Overall, E. coli was susceptible to amoxicillin in 35.9% [95% CI: 34.3-37.5], to amoxicillin/clavulanic acid in 62.2% [95% CI: 60.6-63.9], to cefotaxime in 94% [95% CI: 93.1-94.7], to gentamicin in 92.1% [95% CI: 89.1-92.6], to ofloxacin in 76.8% [95% CI: 75.3-78.2], to trimethoprim/sulfamethoxazole (SXT) in 58.8% [95% CI: 57.1-60.5], to fosfomycin in 99.1% [95% CI: 98.6-99.4], and to nitrofurantoin in 99% of cases [95% CI: 98.6-99.3]. We have observed a gradual decline in the susceptibility profile of E. coli for amoxicillin/clavulanic acid (P <0.001), piperacillin/tazobactam (P = 0.003), and temocillin (P = 0.006). However, susceptibility to ciprofloxacin was increasing (P = 0.001). In contrast, the susceptibility trends for amoxicillin, third-generation cephalosporins, gentamicin, SXT, nitrofurantoin, and fosfomycin remained stable over the 28 quarters of the study. In conclusion, isolated E. coli from outpatient urinalyses showed increased resistance profiles involving penicillinase and ESBL production. Close monitoring and strategies to decrease antibiotic consumption in the community are needed.
Asunto(s)
Antibacterianos , Infecciones por Escherichia coli , Escherichia coli , Pruebas de Sensibilidad Microbiana , Pacientes Ambulatorios , Humanos , Escherichia coli/efectos de los fármacos , Escherichia coli/aislamiento & purificación , Femenino , Infecciones por Escherichia coli/epidemiología , Infecciones por Escherichia coli/microbiología , Infecciones por Escherichia coli/tratamiento farmacológico , Infecciones por Escherichia coli/orina , Masculino , Estudios Retrospectivos , Guyana Francesa/epidemiología , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Pacientes Ambulatorios/estadística & datos numéricos , Adulto , Persona de Mediana Edad , Prevalencia , Infecciones Urinarias/microbiología , Infecciones Urinarias/tratamiento farmacológico , Infecciones Urinarias/epidemiología , beta-Lactamasas/genética , Farmacorresistencia Bacteriana , Anciano , Combinación Trimetoprim y Sulfametoxazol/farmacología , Adulto JovenRESUMEN
A 29-year-old Brazilian illegal gold miner developed intermittent fever. Blood cultures were positive for Gram-negative coccobacilli and, after an initial misidentification by an automated identification system, the diagnosis of brucellosis caused by Brucella suis was confirmed. We hypothesize an association with domestic or wild swine exposure. The patient responded well to standard antibiotic therapy of brucellosis. We report the first case of human brucellosis on the Guiana Shield. This report underlines the importance of considering brucellosis in the presence of a fever of unknown origin, even in the Amazonian rainforest area, where several zoonotic diseases might be considered in the differential diagnosis of unexplained fever.
Asunto(s)
Brucella suis , Brucelosis , Enfermedades de los Porcinos , Animales , Porcinos , Humanos , Adulto , Brasil , Guyana Francesa , Brucelosis/diagnóstico , Brucelosis/tratamiento farmacológico , Zoonosis/diagnóstico , Sus scrofa , FiebreRESUMEN
Bacterial resistance in community-acquired urinary tract infections (UTIs) is increasing worldwide. Our study aimed to assess the microbiological epidemiology and antimicrobial susceptibility patterns of community-acquired urine bacterial isolates in French Amazonia. Our study is retrospective. It was conducted from January 2015 to December 2019 in the microbiology laboratory of the Cayenne General Hospital (French Guiana). It includes all positive urine samples from adult (> 18 years) outpatients (N = 2,533). Isolated microorganisms were Gram-negative rods in 83.9%, mainly Enterobacterales (98.4%). The main isolated bacteria were Escherichia coli (58.7%) and Klebsiella pneumoniae (13.3%). Among the isolated E. coli, 37.2% were susceptible to amoxicillin, 77.9% to amoxicillin/clavulanic acid, 94.9% to cefotaxime, 78.9% to ofloxacin, and 98.9% to nitrofurantoin. In 106 cases (5.1%), isolated Enterobacterales were extended-spectrum ß-lactamase producers (5% of E. coli and 8.9% of K. pneumoniae). Overall, high levels of cross- and co-resistance were registered. The main isolated Gram-positive bacteria was Staphylococcus saprophyticus (28.9%). It was resistant to oxacillin in 52.5% of cases and susceptible to nitrofurantoin in 99.1% of cases. Patients with S. saprophyticus were young women in almost all cases. In conclusion, the most isolated microorganisms from outpatient urinalyses were E. coli and K. pneumoniae. They showed a high resistance rate to amoxicillin, but they were susceptible to the most remaining antibiotics. S. saprophyticus was isolated mainly in young women and was resistant to oxacillin in half of the cases. Interestingly, nitrofurantoin was active against most isolated organisms and can be considered as empirical treatment in uncomplicated UTIs.
Asunto(s)
Infecciones Comunitarias Adquiridas , Infecciones Urinarias , Adulto , Humanos , Femenino , Nitrofurantoína , Escherichia coli , Estudios Retrospectivos , Pruebas de Sensibilidad Microbiana , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Infecciones Urinarias/tratamiento farmacológico , Infecciones Urinarias/epidemiología , Infecciones Urinarias/microbiología , Infecciones Comunitarias Adquiridas/epidemiología , Combinación Amoxicilina-Clavulanato de Potasio , OxacilinaRESUMEN
Source of many myths, French Guiana represents an exceptional territory due to the richness of its biodiversity and the variety of its communities. The only European territory in Amazonia, surrounded by the Brazilian giant and the little-known Suriname, Ariane 6 rockets are launched from Kourou while 50% of the population lives below the poverty line. This paradoxical situation is a source of health problems specific to this territory, whether they be infectious diseases with unknown germs, intoxications or chronic pathologies.Some infectious diseases such as Q fever, toxoplasmosis, cryptococcosis or HIV infection are in common with temperate countries, but present specificities leading to sometimes different management and medical reasoning. In addition to these pathologies, many tropical diseases are present in an endemic and / or epidemic mode such as malaria, leishmaniasis, Chagas disease, histoplasmosis or dengue. Besides, Amazonian dermatology is extremely varied, ranging from rare but serious pathologies (Buruli ulcer, leprosy) to others which are frequent and benign such as agouti lice (mites of the family Trombiculidae) or papillonitis. Envenomations by wild fauna are not rare, and deserve an appropriate management of the incriminated taxon. Obstetrical, cardiovascular and metabolic cosmopolitan pathologies sometimes take on a particular dimension in French Guiana that must be taken into account in the management of patients. Finally, different types of intoxication are to be known by practitioners, especially due to heavy metals.European-level resources offer diagnostic and therapeutic possibilities that do not exist in the surrounding countries and regions, thus allowing the management of diseases that are not well known elsewhere.Thanks to these same European-level resources, research in Guyana occupies a key place within the Amazon region, despite a smaller population than in the surrounding countries. Thus, certain pathologies such as histoplasmosis of the immunocompromised patient, Amazonian toxoplasmosis or Q fever are hardly described in neighboring countries, probably due to under-diagnosis linked to more limited resources. French Guiana plays a leading role in the study of these diseases.The objective of this overview is to guide health care providers coming to or practicing in French Guiana in their daily practice, but also practitioners taking care of people returning from French Guiana.
Asunto(s)
Enfermedades Transmisibles , Cuniculidae , Infecciones por VIH , Histoplasmosis , Enfermedades no Transmisibles , Fiebre Q , Toxoplasmosis , Animales , Humanos , Guyana Francesa/epidemiología , Toxoplasmosis/diagnósticoRESUMEN
A prospective study was conducted among different intra and extra-hospital populations of French Guiana to evaluate the performance of saliva testing compared to nasopharyngeal swabs. Persons aged 3 years and older with mild symptoms suggestive of COVID-19 and asymptomatic persons with a testing indication were prospectively enrolled. Nasopharyngeal and salivary samples were stored at 4°C before analysis. Both samples were analyzed with the same Real-time PCR amplification of E gene, N gene, and RdRp gene. Between July 22th and October 28th, 1159 persons were included, of which 1028 were analyzed. When only considering as positives those with 2 target genes with Ct values <35, the sensitivity of RT-PCR on saliva samples was 100% relative to nasopharyngeal samples. Specificity positive and negative predictive values were above 90%. Across a variety of cultures and socioeconomic conditions, saliva tests were generally much preferred to nasopharyngeal tests and persons seemed largely confident that they could self-sample. For positive patients defined as those with the amplification of 2 specific target genes with Ct values below 35, the sensitivity and specificity of RT-PCR on saliva samples was similar to nasopharyngeal samples despite the broad range of challenging circumstances in a tropical environment.
Asunto(s)
Prueba de Ácido Nucleico para COVID-19/métodos , Saliva/virología , Adolescente , Adulto , Anciano , Prueba de Ácido Nucleico para COVID-19/normas , Niño , Preescolar , Femenino , Guyana Francesa , Hospitales/estadística & datos numéricos , Humanos , Masculino , Persona de Mediana Edad , Nasofaringe/virología , Aceptación de la Atención de Salud , Sensibilidad y Especificidad , Clima TropicalRESUMEN
Current testing for COVID-19 relies on reverse-transcriptase polymerase chain reaction from a nasopharyngeal swab specimen. Saliva samples have advantages regarding ease and painlessness of collection, which does not require trained staff and may allow self-sampling. We enrolled 776 persons at various field-testing sites and collected nasopharyngeal and pooled saliva samples. One hundred sixty two had a positive COVID-19 RT-PCR, 61% were mildly symptomatic and 39% asymptomatic. The sensitivity of RT-PCR on saliva samples vs. nasopharygeal swabs varied depending on the patient groups considered or on Ct thresholds. There were 10 (6.2%) patients with a positive saliva sample and a negative nasopharyngeal swab, all of whom had Ct values <25 for three genes. For symptomatic patients for whom the interval between symptoms onset and sampling was <10 days sensitivity was 77% but when excluding persons with isolated N gene positivity (54/162), sensitivity was 90%. In asymptomatic patients, the sensitivity was only 24%. When we looked at patients with Cts <30, sensitivity was 83 or 88.9% when considering two genes. The relatively good performance for patients with low Cts suggests that Saliva testing could be a useful and acceptable tool to identify infectious persons in mass screening contexts, a strategically important task for contact tracing and isolation in the community.