Chlamydia trachomatis infection in Cuban adolescent and young populations.

BACKGROUND: In Cuba, little is known regarding the prevalence of Chlamydia trachomatis (CT) infection in adolescents and young people. We study the frequency of CT infection in these populations, and its association with clinical-epidemiological variables. METHODS: A total of 496 individuals aged 12 to 24 were recruited from November 2018 to November 2019. Of them, 302 were patients attending at sexually transmitted infections (STI) services and 194 were young volunteers. CT detections were carried out by real-time PCR and IgG serology. RESULTS: The prevalence of CT using PCR was 9.1% (45/496); 12.3% (37/302) for subjects attending STI service and 4.1% (8/194) for young volunteers, being significantly higher in the first group (OR=3.25; p=.001). CT IgG antibodies was detected in 38.6% (81/210). Individuals from 12 to 17 years old were more likely infected with CT (OR=2.21; p=.010). Infection was associated with the early onset of sexual intercourse, the frequent changing of sexual partners and black ethnicity. CONCLUSIONS: The results suggest that Cuban adolescents and young populations are at highest risk of acquiring CT infection and developing reproductive complications. The data obtained advise the needs of implementation of a routine CT screening strategy, for timely diagnosis, detection and treatment at the earliest ages.

Evaluación de estuches de PCR-tiempo real para detección de virus del papiloma humano de alto riesgo / Evaluation of real-time PCR kits to detect high-risk human papillomavirus

RESUMEN Introducción: El empleo de técnicas moleculares para el diagnóstico de virus del papiloma humano de alto riesgo oncogénico (VPH-AR) es crucial para la detección precoz del cáncer cervicouterino. Objetivo: Evaluar el desempeño analítico de dos estuches de PCR-tiempo real, comercializados por el Centro de Inmunoensayo de Cuba, para detectar VPH-AR. Métodos: Se utilizaron dos paneles de ADN de muestras cervicouterinas: uno con 150 muestras, para validar el estuche SUMASIGNAL HPV 16/18, el proceso de extracción de ADN y su utilidad como prueba cuantitativa, y otro con 163 muestras para evaluar el estuche HPV 13+2. Se determinó la utilidad clínica del estuche HPV 13+2 en 55 muestras cervicovaginales autocolectadas. Se calcularon los indicadores de desempeño analítico de ambos estuches con respecto a pruebas de referencia. Resultados: Los indicadores de desempeño para SUMASIGNAL HPV 16/18 fueron excelentes (> 95 %), concordancia 96 %, índice kappa=0,93 [0,85-1,01]. La extracción de ADN mostró 100 % de especificidad clínica y analítica y 95 % de sensibilidad analítica. Se obtuvo buena correlación con la prueba de referencia cuantitativa (r = + 0,688). El estuche HPV 13+2 tuvo especificidad y sensibilidad clínicas del 100 %, la especificidad analítica fue del 84 % debido a reactividad cruzada con otros VPH-AR. Su aplicación clínica reveló alta frecuencia de infección (41,8 %): 23,6 % con VPH-AR, particularmente en mujeres jóvenes (50 %). La muestra autocolectada resultó útil (100 %). Conclusión: Los ensayos evaluados mostraron altos estándares de calidad, lo que permitiría su uso con una cobertura nacional en una plataforma tecnológica disponible para todo el país.

ABSTRACT Introduction: The use of molecular techniques for the diagnosis of high oncogenic risk human papillomavirus (hrHPV) is crucial for the early detection of cervical cancer. Objective: To evaluate the analytical performance of two real-time PCR kits, commercialized by the Cuban Immunoassay Center, to detect hrHPV. Methods: Two DNA panels from cervical samples were used: one with 150 samples to validate the SUMASIGNAL HPV 16/18 kit, the DNA extraction process and its usefulness as a quantitative test; and another with 163 samples to evaluate the HPV 13+2 kit. The clinical utility of the HPV 13+2 kit was determined in 55 self-collected cervicovaginal samples. The analytical performance indicators of both kits were calculated with respect to reference tests. Results: Performance indicators for SUMASIGNAL HPV 16/18 were excellent (>95%), concordance 96%, kappa index=0.93 [0.85-1.01]. DNA extraction showed 100% clinical and analytical specificity and 95% analytical sensitivity. Good correlation was obtained with the quantitative reference test (r = + 0.688). The HPV 13+2 kit had 100% clinical specificity and sensitivity, analytical specificity was 84% due to cross-reactivity with other hrHPVs. Its clinical application revealed a high frequency of infection (41.8%): 23.6% with hrHPV, particularly in young women (50%). The self-collected sample was viable (100%). Conclusion: The assays evaluated showed high quality standards, which would allow their use with national coverage in a technological platform available for the whole country.

Infecciones múltiples por Alphapapillomavirus, especie 9, en mujeres ecuatorianas con lesiones intraepiteliales y cáncer cervicouterino / Multiple infections by Alphapapillomavirus, specie 9, in Ecuadorian women with intraepithelial lesions and cervical cancer

Introducción: El significado biológico de las infecciones múltiples con virus del papiloma humano de alto riesgo oncogénico (VPH-AR), pertenecientes a la familia Alphapapillomavirus, en la carcinogénesis cervical aún es controversial. Objetivo: Proporcionar información sobre la circulación del VPH-AR del género Alphapapillomavirus-especie 9, e infecciones múltiples en mujeres ecuatorianas con lesiones intraepiteliales y cáncer cervicouterino (CaCU). Métodos: Se estudiaron 300 mujeres, residentes en la región Litoral del Ecuador. Se detectó la infección viral en muestras cervicales, mediante PCR anidada con cebadores genéricos MY09/11 y GP5/GP6. Los genotipos virales fueron identificados con el sistema comercial ANYPLEX II VPH28. La razón de prevalencia (RP) fue utilizada como medida de asociación entre las lesiones citológicas y las infecciones simples, múltiples o combinaciones de genotipos. Resultados: Se detectó VPH en el 92,00 % (276/300) de las mujeres, con frecuencias altas de infección por genotipos individuales, principalmente de alto riesgo oncogénico. Los VPH-AR más frecuentes fueron VPH58 (18,17 por ciento), 70 (8,64 por ciento), 53 (8,34 por ciento), 35 (7,45 por ciento), 16 (7,37 por ciento), 33 (6,55 por ciento), 31 (5,58 por ciento) y 18 (4,24 por ciento). En el 91,66 por ciento (253/276) de las muestras se detectaron infecciones múltiples, hasta con 13 tipos en una misma paciente, incluyendo varias especies del género Alphapapillomavirus. La combinación VPH16/VPH58 fue la más frecuente en lesiones de alto grado (RP = 2,9; p = 0,000), y la coinfección triple VPH16/VPH58/VPH70 predominó en las mujeres con CaCU (RP = 3,5; p = 0,007). Conclusión: Los resultados demuestran que la combinación VPH16/VPH58 del género Alphapapillomavirus, especie 9, podría ser un factor clave en la aparición de lesiones premalignas y su progresión hacia el CaCU(AU)

Introduction: It is still controversial the biological connotation of multiple infections with high-risk human papillomaviruses (hrHPV), that belong to the genus Alphapapillomavirus, for the cervical carcinogenesis. Objective: To provide information on the circulation of hrHPV, genus Alphapapillomavirus, specie 9, and the multiple infections in Ecuadorian women with intraepithelial lesions and cervical cancer. Methods: 300 women, from the coastal region of Ecuador, were screened. Viral infection was detected in cervix samples by nested PCR with MY09/11 and GP5/GP6 generic primers. Viral genotypes were identified using the commercial kit ANYPLEX II VPH28. The prevalence ratio (PR) was used to measure the association between cytological lesions and the simple, multiple or combined genotype infections. Results: Ninety-two percent of women (276/300) tested positive for HPV. Frequency of infection for single genotypes was high, mainly those of high oncogenic risk. The most frequent hrHPV genotypes were HPV58 (18.17 percent), 70 (8.64 percent), 53 (8.34 percent), 35 (7.45 percent), 16 (7.37 percent), 33 (6.55 percent), 31 (5.58 percent) and 18 (4.24 percent). In 91.66 percent (253/300) of the samples, multiple infections were detected, with up to 13 types in a single patient, including various species from the genus Alphapapillomavirus. The combination HPV16/HPV58 was the most frequent on high-grade lesions (PR = 2.9; p = 0,000), and HPV16/HPV58/HPV70 triple co-infection prevailed in women with cervical cancer (PR = 3.5; p = 0.007). Conclusions: The results evidence that the combination HPV16/HPV58, genus Alphapapillomavirus, specie 9, could be a key factor in the occurrence of premalignant lesions and their evolution into cervical cancer(AU)

Subtype-Dependent Co-receptor Tropism in Cuban HIV-1-Infected Patients: Implications for Maraviroc Treatment.

INTRODUCTION: Unlike most high-income countries where subtype B viruses predominate, the Cuban HIV-1 epidemic is characterized by a great diversity of subtypes and circulating recombinant forms. Some studies have shown that HIV variants exhibiting a preference for the CXCR4 co-receptor (X4-tropic) could have impacts on disease pathogenesis, with clinical implications for antiviral treatment plans. Determination of HIV co-receptor tropism is crucial for clinicians in deciding whether maraviroc is an appropriate antiviral. OBJECTIVE: Characterize V3 sequence variability and its relation to viral tropism across different subtypes circulating in Cuba and explore how this may affect treatment success with maraviroc. METHODS: We designed a cross-sectional study that included 72 plasma samples obtained at the Pedro Kourí Tropical Medicine Institute in Havana, Cuba. We sequenced the C2V3 env region and assessed subtype based both on env and pol sequences; tropism was predicted by Geno2pheno analysis. Additionally, 35 V3-loop Cuban sequences, obtained from a previous study, were incorporated into the analysis. Statistical associations among virological, clinical and epidemiological variables were assessed by a chi-square test. RESULTS: Tropism prediction for 72 variants revealed that CRF19_cpx was associated with dual-tropic R5X4 viruses (p = 0.034). Moreover, when 35 sequences from a former study were added, the association was significant not only for R5X4 (p = 0.019) but also for X4-tropic variants (p = 0.044). Alignment of 107 V3-loop sequences showed wide diversity among the different HIV-1 subtypes circulating in Cuba. CONCLUSIONS: In accordance with G2P, CRF19_cpx is a genetic variant with a high proportion of X4 and R5X4-tropic viruses. The results from the present study suggest that the Cuban recombinant could be a more pathogenic variant and that maraviroc may not be suitable for patients infected with CRF19_cpx.

Circulation of Human Papillomavirus and Chlamydia trachomatisin Cuban Women.

INTRODUCTION Human papillomaviruses and Chlamydia tracho-matis are the most frequent causes of sexually transmitted infec-tions. Although the association between some human papillomavirus genotypes and cervical cancer has been demonstrated and Chla-mydia trachomatis infection is the most common cause of female infertility, Cuba has no national baseline studies on the circulation and co-circulation of these agents, the synergistic effect of which may be a risk factor for occurrence and development of precancer-ous cervical lesions. Additionally, few local studies have examined risk factors for infection.OBJECTIVE Determine the frequency of infection by human papil-lomavirus and Chlamydia trachomatis and their association with sociodemographic, clinical and epidemiological variables in women seeking routine Pap smears or other medical services at the primary care level in Cuba.METHODS A cross-sectional study was conducted among 500 wom-en aged 16-67 years (100 from Havana, 200 from Villa Clara and 200 from Holguín Provinces, Cuba), from August through December 2015. Chlamydia trachomatis infection was detected by real-time polymerase chain reaction and 35 genotypes of human papillomavirus by low-density microarray. We then examined the association of infec-tion with sociodemographic, clinical and epidemiological variables.RESULTS Human papillomavirus was detected in 14.8% (74/500) of the women. Of the 29 genotypes identifi ed, 79.7% (59/74) were onco-genic high-risk types. Type 16 was the most frequently identifi ed (23%; 17/74), followed by type 31 (10.8%; 8/74) and then by types 33, 53, 61 and 66 in equal proportions (8.1%; 6/74). Infection frequency was greater in women aged ≤25 years (38.8%; 31/80), students (46.7% 7/15), single women (23.0%; 40/174) and among those who reported having more than 3 sexual partners in the last 2 years (41.5%; 17/41). Differences were found among provinces for circulating genotypes and infection-related variables. Human papillomavirus infection from genotypes 16, 31, 33, 53, 61, 66, 68 and 89 was associated with the 7.9% (30/382) of women who had positive Pap tests. Infection fromChlamydia trachomatis was positive in 1% (5/500) of women, all aged ≤25 years. Coinfection by Chlamydia trachomatis and HPV was found in one woman infected with human papillomavirus genotype 61.CONCLUSIONS Frequency of human papillomavirus is high in the three Cuban provinces studied, with greater frequency of genotype 16 and other oncogenic high-risk types. For both agents, infection is more frequent in young women and adolescents. Positive Pap tests are fre-quently associated with HPV infection. Prevalence fi ndings from this study could be used as a baseline for future research or interventions. KEYWORDS Human papillomavirus, genotypes, Chlamydia tracho-matis, neoplasms, sexually transmitted diseases, cervix Uteri, infec-tion, real-time polymerase chain reaction, women, Cuba.

Infección por virus del papiloma humano en mujeres del Cantón Cañar, Ecuador / Human papillomavirus infection among women from Cañar Canton in Ecuador

Introducción: Existen pocos estudios sobre la circulación del virus del papiloma humano en mujeres ecuatorianas, particularmente residentes en el Cantón Cañar. Objetivo: Determinar la circulación del virus del papiloma humano, las alteraciones en la citología cérvico-vaginal de mujeres cañaríes y el comportamiento de algunas variables sociodemográficas y clínico-epidemiológicas. Métodos: Estudio analítico de corte transversal desde julio 2017-septiembre 2018. Se colectaron células cervicouterinas de 100 mujeres entre 15 y 55 años de edad para determinar la infección viral y alteraciones citológicas. Se investigó la asociación entre variables sociodemográficas y clínico-epidemiológicas con la infección viral. Resultados: El 51 por ciento (51/100) de las mujeres examinadas resultó positivo al virus, con predominio de los genotipos oncogénicos. El genotipo 31 fue el más frecuente (56,9 por ciento; 29/51), seguido por el genotipo 58 (43,1 por ciento; 22/51). Las mujeres mayores de 50 años, tenían una probabilidad menor de estar infectadas (3,9 por ciento; 2/51). La probabilidad de infección fue mayor en mujeres solteras, con antecedentes de infecciones de transmisión sexual, que padecían procesos cervicales inflamatorios, y en las fumadoras. La infección con genotipo 66 estuvo asociada al uso de anticonceptivos hormonales (53,3 por ciento; 8/15); p= 0,045, RP= 3,08 IC95 por ciento (1,00-9,46). Se obtuvo el 97 por ciento de citologías negativas para malignidad; no se diagnosticaron casos con lesiones de alto grado. Conclusiones: La elevada prevalencia de infección con genotipos oncogénicos en contraste con la baja frecuencia de citologías positivas, indica la necesidad de implementar programas eficientes para la detección precoz del cáncer cervicouterino en la población del Cañar y divulgar campañas de educación sexual y reproductiva(AU)

Introduction: Few studies are available about the circulation of human papillomavirus among Ecuadorian women, particularly those from Cañar Canton. Objectives: Determine the circulation of human papillomavirus, alterations in the cervical-vaginal cytology of women from Cañar Canton, and the behavior of some sociodemographic and clinical-epidemiological variables. Methods: An analytical cross-sectional study was conducted from July 2017 to September 2018. Cervical cells were collected from 100 women aged 15-55 years to determine viral infection and cytological alterations. An analysis was performed of the relationship of sociodemographic and clinical-epidemiological variables to viral infection. Results: Of the women examined, 51 percent; (51/100) tested positive for the virus, with a predominance of oncogenic genotypes. Genotype 31 was the most common (56.9 percent;; 29/51), followed by genotype 58 (43.1 percent; 22/51). Women aged over 50 years had a lesser probability of being infected (3.9 percent;; 2/51). Infection probability was greater among single women, with a history of sexually transmitted infections, who suffered from inflammatory cervical processes, and smokers. Infection by genotype 66 was associated to the use of hormonal contraceptives (53.3 percent;; 8/15); p= 0.045, PR= 3.08 CI95 percent; (1.00-9.46). Of the sample cytologies, 97 percent; were negative for malignancy; no case was diagnosed of high-grade lesions. Conclusions: The high prevalence of infection by oncogenic genotypes, as opposed to the low frequency of positive cytologies, points to the need to implement efficient programs aimed at early detection of cervical cancer in the population of Cañar Canton, as well as sexual and reproductive education campaigns(AU)

HIV-1 Antiretroviral Resistance in Cuba, 2009-2014.

INTRODUCTION By the end of 2017, there were more than 28,000 individuals living with HIV in Cuba, over 80% receiving antiretroviral therapy, which dramatically reduces viral replication, improves immune status and decreases risk of transmission. These results could be jeopardized by emergence of HIV-1 drug resistance. In 2009, a test for HIV-1 genotypic resistance was introduced in routine clinical practice in Cuba. OBJECTIVE Investigate antiretroviral resistance and its relation to subtype distribution in HIV-1 treatment-naïve and previously treated patients in Cuba. METHODS Resistance and HIV-1 subtype distribution were determined in 342 antiretroviral treatment-naïve patients and 584 previously treated for HIV-1 whose blood specimens were sent to the Pedro Kourí Tropical Medicine Institute during 2009-2014. Transmitted drug resistance was determined using the Calibrated Population Resistance Tool v.6. Drug resistance analysis was conducted using the algorithm Rega v9.1.0. RESULTS Prevalence of transmitted drug resistance was 11.4%, and 41% of mutated viruses exhibited dual-class resistance to nucleoside reverse transcriptase inhibitor and non-nucleoside reverse transcriptase inhibitor. Overall, 84.9% of patients had ≥1 resistance mutation, 80% had ≥1 nucleoside reverse transcriptase inhibitor mutation, 71.4% had ≥1 non-nucleoside reverse transcriptase inhibitor mutation and 31.7% had ≥1 protease inhibitor mutation. K65R and K101E mutations were significantly more frequent in subtype C, L210W in CRF19_cpx, and M47V/I in CRF BGs (20, 23, 24). Full class resistance to nucleoside reverse transcriptase inhibitors, non-nucleoside reverse transcriptase inhibitors, protease inhibitors and multidrug resistance were detected in 21.2%, 32.4%, 8% and 4.1% of patients, respectively. Average percentage resistance to nucleoside reverse transcriptase inhibitor, protease inhibitor, full class resistance to nucleoside reverse transcriptase inhibitor, protease inhibitor and multidrug resistance increased in patients failing two or more regimens. Nevertheless, after 2011, a declining trend was observed in the frequency of multidrug resistance and full class resistance to nucleoside reverse transcriptase inhibitors and protease inhibitors. CONCLUSIONS Detected levels of transmitted drug resistance highlight the need for a national surveillance study in treatment-naïve patients. Resistance prevalence is high in previously treated patients but appears to be decreasing over time. The frequency of resistance mutations in recombinant forms of HIV in Cuba needs further study. KEYWORDS Antiretroviral therapy, highly active antiretroviral therapy, HIV, anti-HIV agents, drug resistance, multiple drug resistance, Cuba.

Normalización de un método inmunoquímico para detectar Papilomavirus humano tipo 16 en lesiones cérvico-uterinas / Standardization of immunochemical method for detection of type 16 human papilomavirus in cervix uterine lesions

Introducción: la infección por Papilomavirus Humano (PVH) es la condición necesaria para la aparición y desarrollo del cáncer cérvico-uterino. Los genotipos de alto riesgo oncogénico son los causantes de este tipo de neoplasia y dentro de ellos el más frecuente es el PVH 16, que se encuentra aproximadamente en el 60 % de los casos. Los métodos de diagnóstico comerciales resultan costosos para países con escasos recursos económicos, lo que sugiere la búsqueda de alternativas empleando protocolos sencillos y baratos. Objetivos: normalizar un método inmunoquímico para la detección del antígeno L1 de PVH tipo 16 en muestras cérvico-uterinas de pacientes con lesiones intraepiteliales escamosas y determinar la coincidencia entre el método normalizado y la Reacción en Cadena de la Polimerasa en Tiempo Real (RCP-TR), como técnica de referencia, para estimar la utilidad de dicho método en el diagnóstico de la infección por este genotipo viral. Métodos: se compararon tres procedimientos de inmunotinción (Indirecto de inmunoperoxidasa en dos pasos, Estreptavidina-Biotina y Amplificación por polímero) respecto a sensibilidad analítica, tinción inespecífica de fondo y tiempo de terminación, para la detección de la proteína L1 de PVH 16 en líneas celulares derivadas de carcinomas cervicales humanos y en muestras cérvico-uterinas utilizadas como controles. El protocolo normalizado se aplicó a muestras cérvico-uterinas de mujeres entre 30 y 59 años, 82 con lesiones intraepiteliales cervicales y 10 sin antecedentes de alteraciones citológicas, a las que además se les determinó PVH 16 mediante RCP-TR. Resultados: el procedimiento de Estreptavidina-Biotina resultó el más sensible y específico. La coincidencia entre el método inmunoquímico y la RCP-TR fue de un 98,6 por ciento, la sensibilidad fue de un 98,57 por ciento y la especificidad de un 91,67 por ciento, con valores predictivos negativo y positivo por encima del 90 por ciento. Conclusiones: se demostró la validez del método inmunoquímico como prueba confirmatoria de la infección por PVH 16. Dicho método probó ser sensible, sencillo y no requiere de una compleja infraestructura para detectar PVH 16 en muestras cervicales. Además, esta técnica permite obtener información rápidamente y evita el uso de métodos invasivos(AU)

Introduction: Human Papillomavirus (HPV) infection is the necessary condition for the occurernce and development of cervical cancer. The high oncogenic risk genotypes are the responsible for this type of neoplasia and the most frequent is HPV 16 that affects roughly 60 percent of cases. Commercial kits for HPV detection are expensive for resource-poor countries, which suggests the search for alternative throguh non-expensive simple protocoles. Objectives: to standardize an immunochemical method for the detection of HPV 16 L1 antigen in cervical samples of patients with squamous intraepithelial lesions and to determine the diagnostic coincidence between the immunochemical method and the real-time polymerase chain reaction to estimate the usefulness of this method for the detection of cervical infection with this viral genotype. Methods: three immunostaining methods (Two-Step Indirect Immunoperoxidase, Labelled Streptavidin-Biotin and Enhanced Polymer) were compared in terms of analytical sensitivity, nonspecific background staining and time of completion, for the detection of protein L1 of HPV-16 in a cell line derived from human cervical carcinoma and clinical samples from uterine cervix. The optimized protocol was applied to 82 cervical samples from women aged 30-59 years with squamous intraepithelial lesions and to 10 samples of sexually active women without previous signals of positive cytology. The presence of type 16 HPV was also detected with the aid of RT-PCR. Results: the Streptavidin-Biotin system was the most sensitive and specific. The diagnostic agreement between the immunochemical method and the real-time polymerase chain reaction reached 98.6 percent, sensitivity was 98.57 percent and specificity was 91.67 %, with positive and negative predictive values above 90 percent. Conclusions: the validity of the immunochemical method as a confirmatory test for infection by HPV-16 has been demonstrated. The normalized immunochemical method proved to be a sensitive, simple, relatively fast method to detect HPV from clinical samples of cervical cells. Furthermore, this method provides information quickly, avoiding the use of invasive methods in patients(AU)

Normalización de un método inmunoquímico para detectar Papilomavirus humano tipo 16 en lesiones cérvico-uterinas / Standardization of immunochemical method for detection of type 16 human papilomavirus in cervix uterine lesions

Introducción: la infección por Papilomavirus Humano (PVH) es la condición necesaria para la aparición y desarrollo del cáncer cérvico-uterino. Los genotipos de alto riesgo oncogénico son los causantes de este tipo de neoplasia y dentro de ellos el más frecuente es el PVH 16, que se encuentra aproximadamente en el 60 por ciento de los casos. Los métodos de diagnóstico comerciales resultan costosos para países con escasos recursos económicos, lo que sugiere la búsqueda de alternativas empleando protocolos sencillos y baratos. Objetivos: normalizar un método inmunoquímico para la detección del antígeno L1 de PVH tipo 16 en muestras cérvico-uterinas de pacientes con lesiones intraepiteliales escamosas y determinar la coincidencia entre el método normalizado y la Reacción en Cadena de la Polimerasa en Tiempo Real (RCP-TR), como técnica de referencia, para estimar la utilidad de dicho método en el diagnóstico de la infección por este genotipo viral. Métodos: se compararon tres procedimientos de inmunotinción (Indirecto de inmunoperoxidasa en dos pasos, Estreptavidina-Biotina y Amplificación por polímero) respecto a sensibilidad analítica, tinción inespecífica de fondo y tiempo de terminación, para la detección de la proteína L1 de PVH 16 en líneas celulares derivadas de carcinomas cervicales humanos y en muestras cérvico-uterinas utilizadas como controles. El protocolo normalizado se aplicó a muestras cérvico-uterinas de mujeres entre 30 y 59 años, 82 con lesiones intraepiteliales cervicales y 10 sin antecedentes de alteraciones citológicas, a las que además se les determinó PVH 16 mediante RCP-TR. Resultados: el procedimiento de Estreptavidina-Biotina resultó el más sensible y específico...

Introduction: Human Papillomavirus (HPV) infection is the necessary condition for the occurernce and development of cervical cancer. The high oncogenic risk genotypes are the responsible for this type of neoplasia and the most frequent is HPV 16 that affects roughly 60 percent of cases. Commercial kits for HPV detection are expensive for resource-poor countries, which suggests the search for alternative throguh non-expensive simple protocoles. Objectives: to standardize an immunochemical method for the detection of HPV 16 L1 antigen in cervical samples of patients with squamous intraepithelial lesions and to determine the diagnostic coincidence between the immunochemical method and the real-time polymerase chain reaction to estimate the usefulness of this method for the detection of cervical infection with this viral genotype. Methods: three immunostaining methods (Two-Step Indirect Immunoperoxidase, Labelled Streptavidin-Biotin and Enhanced Polymer) were compared in terms of analytical sensitivity, nonspecific background staining and time of completion, for the detection of protein L1 of HPV-16 in a cell line derived from human cervical carcinoma and clinical samples from uterine cervix. The optimized protocol was applied to 82 cervical samples from women aged 30-59 years with squamous intraepithelial lesions and to 10 samples of sexually active women without previous signals of positive cytology. The presence of type 16 HPV was also detected with the aid of RT-PCR. Results: the Streptavidin-Biotin system was the most sensitive and specific...

Normalización de un sistema de reacción en cadena de la polimerasa en tiempo real para la cuantificación del herpesvirus humano 8 / Standardization of a real-time polymerase chain reaction system for quantification of human herpesvirus 8

OBJETIVO: normalizar un sistema de reacción en cadena de la polimerasa en tiempo real para determinar la carga viral del herpesvirus humano 8, en diferentes muestras clínicas de pacientes en los que se sospeche la infección por este agente. MÉTODOS: se evaluaron 3 de los métodos reportados internacionalmente para obtener ADN estándar en la construcción de curvas externas estándar, que permiten determinar el número de copias de ADN diana en la muestra problema. RESULTADOS: se obtuvieron 3 ADN estándar a partir del clonaje de un fragmento del gen ORF26 del herpesvirus humano 8 en un vector (ADN plasmídico), con la utilización de productos purificados de reacción en cadena de la polimerasa y el empleo de ADN genómico de la línea celular BCBL. Se pudieron construir las curvas patrón a partir de cada uno de los ADN estándar obtenidos, los que mostraron una fuerte correlación lineal (r= -1) y valores muy bajos de error a lo largo de 6 magnitudes de concentración de ADN diana. El límite inferior de detección a partir del ADN plasmídico y de los productos de reacción en cadena de la polimerasa fue de hasta 100 copias, mientras que con el ADN genómico fue de hasta 10 copias; este último sistema resultó el más sensible. CONCLUSIONES: la reacción en cadena de la polimerasa en tiempo real normalizada a partir de los 3 ADN estándar probó ser un sistema rápido, específico y altamente sensible que permitirá un mejor diagnóstico y además desarrollar estudios sobre la patogenia de la infección por el herpesvirus humano 8 en Cuba(AU)

OBJECTIVE: to standardize a real-time polymerase chain reaction system to determine the human herpes virus 8 viral load in several samples from patients suspected of this type of infection. METHODS: three internationally known methods were evaluated to obtain standard DNA in standard external curve constructions, which allow determining the number of target DNA copies in the suspected samples. RESULTS: three standards DNA were obtained from cloning ORF26 gene fragment of human herpesvirus 8 in a vector (plasmid DNA), with the use of purified polymerase chain reaction products and of genomic DNA of BCBL cell lines. The pattern curves were constructed on the basis of each of the resulting standard DNA, which showed strong linear correlation (r= -1) and very low error values throughout 6 target DNA concentrations. The lower detection limit based on plasmid DNA and the polymerase chain reaction products was 100 copies, whereas that obtained with genomic DNA reached up to 10 copies; this last system turned to be the most susceptible. CONCLUSIONS: real-time polymerase chain reaction system, standardized for the three standard DNA proved to be a rapid, specific and highly sensitive system for better diagnosis, and for the development of studies on the pathogenesis of human herpesvirus 8 infection in Cuba(AU)

Normalización de un sistema de reacción en cadena de la polimerasa en tiempo real para la cuantificación del herpesvirus humano 8 / Standardization of a real-time polymerase chain reaction system for quantification of human herpesvirus 8

OBJETIVO: normalizar un sistema de reacción en cadena de la polimerasa en tiempo real para determinar la carga viral del herpesvirus humano 8, en diferentes muestras clínicas de pacientes en los que se sospeche la infección por este agente. MÉTODOS: se evaluaron 3 de los métodos reportados internacionalmente para obtener ADN estándar en la construcción de curvas externas estándar, que permiten determinar el número de copias de ADN diana en la muestra problema. RESULTADOS: se obtuvieron 3 ADN estándar a partir del clonaje de un fragmento del gen ORF26 del herpesvirus humano 8 en un vector (ADN plasmídico), con la utilización de productos purificados de reacción en cadena de la polimerasa y el empleo de ADN genómico de la línea celular BCBL. Se pudieron construir las curvas patrón a partir de cada uno de los ADN estándar obtenidos, los que mostraron una fuerte correlación lineal (r= -1) y valores muy bajos de error a lo largo de 6 magnitudes de concentración de ADN diana. El límite inferior de detección a partir del ADN plasmídico y de los productos de reacción en cadena de la polimerasa fue de hasta 100 copias, mientras que con el ADN genómico fue de hasta 10 copias; este último sistema resultó el más sensible. CONCLUSIONES: la reacción en cadena de la polimerasa en tiempo real normalizada a partir de los 3 ADN estándar probó ser un sistema rápido, específico y altamente sensible que permitirá un mejor diagnóstico y además desarrollar estudios sobre la patogenia de la infección por el herpesvirus humano 8 en Cuba.

OBJECTIVE: to standardize a real-time polymerase chain reaction system to determine the human herpes virus 8 viral load in several samples from patients suspected of this type of infection. METHODS: three internationally known methods were evaluated to obtain standard DNA in standard external curve constructions, which allow determining the number of target DNA copies in the suspected samples. RESULTS: three standards DNA were obtained from cloning ORF26 gene fragment of human herpesvirus 8 in a vector (plasmid DNA), with the use of purified polymerase chain reaction products and of genomic DNA of BCBL cell lines. The pattern curves were constructed on the basis of each of the resulting standard DNA, which showed strong linear correlation (r= -1) and very low error values throughout 6 target DNA concentrations. The lower detection limit based on plasmid DNA and the polymerase chain reaction products was 100 copies, whereas that obtained with genomic DNA reached up to 10 copies; this last system turned to be the most susceptible. CONCLUSIONS: real-time polymerase chain reaction system, standardized for the three standard DNA proved to be a rapid, specific and highly sensitive system for better diagnosis, and for the development of studies on the pathogenesis of human herpesvirus 8 infection in Cuba.

Estudio de la estabilidad genética del sistema de expresión de la proteína E del virus dengue 4 en la levadura metilotrófica Pichia pastoris / Study of the genetical stability of the system of expression of protein E of dengue virus 4 in methyltrophic yeast Pichia pastoris

Se realizó el análisis de la estabilidad plasmídica de la levadura metilotrófica Pichia pastoris que expresa la proteína recombinante E del virus dengue 4. Para ello se estimó el número de generaciones desde el proceso de crecimiento en placa petri hasta la propagación en zaranda, así como el proceso de fermentación. Además se determinó en las colonias seleccionadas el patrón de integración por Dot-Blot y secuencia nucleotídica del gen E del virus dengue 4. Este estudio permitió comprobar la conservación e integridad de la secuencia aminoacídica de la proteína E, a pesar de encontrarse cambios genéticos producidos por mecanismos moleculares de la levadura; por otra parte, formó parte del control y chequeo realizado al banco de células primario de levadura que contiene el gen de interés, actualmente utilizado en el proceso de expresión de la proteína E del virus dengue 4

Estudio de la estabilidad genética del sistema de expresión de la proteína E del virus dengue 4 en la levadura metilotrófica Pichia pastoris / Study of the genetical stability of the system of expression of protein E of dengue virus 4 in methyltrophic yeast Pichia pastoris

Se realizó el análisis de la estabilidad plasmídica de la levadura metilotrófica Pichia pastoris que expresa la proteína recombinante E del virus dengue 4. Para ello se estimó el número de generaciones desde el proceso de crecimiento en placa petri hasta la propagación en zaranda, así como el proceso de fermentación. Además se determinó en las colonias seleccionadas el patrón de integración por Dot-Blot y secuencia nucleotídica del gen E del virus dengue 4. Este estudio permitió comprobar la conservación e integridad de la secuencia aminoacídica de la proteína E, a pesar de encontrarse cambios genéticos producidos por mecanismos moleculares de la levadura; por otra parte, formó parte del control y chequeo realizado al banco de células primario de levadura que contiene el gen de interés, actualmente utilizado en el proceso de expresión de la proteína E del virus dengue 4(AU)

[Study of the genetical stability of the system of expression of protein E of dengue virus 4 in methyltrophic yeast Pichia pastoris]. / Estudio de la estabilidad genética del sistema de expresión de la proteína E del virus dengue 4 en la levadura metilotrófica Pichia pastoris.

The plasmidic stability of methyltrophic yeast Pichia pastoris expressing the recombinant protein E of dengue virus 4 was analyzed. To this end, the number of generations from the growth process in petri plaque to the propagation in zaranda was estimated, as well as the fermentation process. Besides, in the selected colonies the integration pattern was determined by Dot-Blot and neuclotide sequence of the gene E of dengue virus 4. This study allowed to prove the conservation and integrity of the aminoacid sequence of protein E, despite the genetic changes produced by molecular yeast mechanisms. On the other hand, it was also part of the control and checking of the primary bank of yeast cells that contains the gene of interest used at present in the process of expression of protein E of dengue virus 4.