Aníbal Kawabata

Acinetobacter baumannii is a major nosocomial pathogen worldwide and, specifically, in Latin America. Genomic epidemiology has been instrumental in determining the transmission dynamics of A. baumannii in many countries of the world, yet some Latin American countries have conducted no genomic epidemiology studies. Here, we conduct the first genomic epidemiology study about this pathogen in Paraguay. We sequenced 43 isolates from a big tertiary hospital in Paraguay collected from different wards in 2021 and 2022. Our genomic epidemiology analyses, including almost 200 genomes and considering the main international clones (ICs), show that IC1, IC2, IC4, IC5, and IC7 were found in the hospital. We found novel genetic variation (three novel sequence types as per the Oxford MLST scheme and one as per the Pasteur scheme) within IC7. Antibiotic susceptibility tests show that all but one of the Paraguayan isolates were resistant to carbapenems. Notably, 98% were classified as multidrug-resistant. We detected plasmids in almost all the Paraguayan isolates. Furthermore, we detected cases of recent horizontal transfer of important antibiotic resistance genes between different ICs. On a general note, our findings highlight polyclonal spreading across different hospital wards and horizontal transfer of clinically relevant antibiotic resistance genes among the different clones. On a more local note, this is the first genomic epidemiology study of A. baumannii in Paraguay and will be a reference point for future studies in the country and the region.

Objectives. To describe the whole genome sequencing of double-carbapenemase-producing Enterobacteriaceae isolates circulating in Paraguay. Materials and methods. We conducted genomic studies on seven Enterobacteriaceae isolates, previously confirmed as double-carbapenemase producers by PCR, from patients with extended hospital stays and broad-spectrum antimicrobial treatment in seven hospitals in Paraguay. Genome sequencing included Unicycler assembly and multilocus sequence typing (MLST). Results. Of the seven Enterobacterales isolates producing dual carbapenemases, six were Klebsiella pneumoniae subsp. pneumoniae and one was Enterobacter cloacae subsp. cloacae. The co-production of blaKPC-2/blaNDM-1 and blaKPC-2/blaNDM-5 was confirmed in K. pneumoniae. We found co-production of blaNDM-1/blaOXA-163 in E. cloacae, along with other antimicrobial resistance genes of chromosomal and plasmid origin. The MLST sequence types of the K. pneumoniae isolates were ST11, ST15, ST133, ST273, and ST1303, and that of E. cloacae was ST976. Two of the six K. pneumoniae ST11 isolates, from two different hospitals in the capital, were genetically related and both carried blaKPC-2 and blaNDM-5. Conclusions. We report the first genome sequencing of double-carbapenemase-producing Enterobacterales from patients with extended hospital stays in Paraguay. The analysis revealed diverse resistance profiles and clones, carriage of multiple carbapenemases, and other resistance genes of chromosomal and plasmid origin. These findings emphasize the need to strengthen hospital infection control and implement effective therapeutic interventions.

Introduction Invasive meningococcal disease (IMD) remains a significant public health concern and one of the leading causes of morbidity and mortality worldwide. In Paraguay, IMD continues to pose a serious health challenge. Methodology A retrospective, descriptive, cross-sectional observational study was conducted. Whole-genome sequencing was employed to perform multilocus sequence sequence typing (MLST), vaccine antigens characterization, and antimicrobial resistance gene profiling of Neisseria meningitidis isolates obtained from children and adults with IMD, as part of the Bacterial Meningitis Surveillance Program in Paraguay during 2009–2021. Results Eight clonal complexes were identified, with cc103 being the most frequent, followed by cc11, cc35, cc167, cc41/44, cc865, cc32, and cc60. Regarding vaccine antigens, the fHbp variant A05 peptide targeted by MenB-FHbp was absent, whereas the B01 variant was detected in 3 out of 70 isolates (4.3%). For the 4CMenB vaccine components, peptide 1 of fHbp (subfamily B/variant 1), NHBA peptide 2, and NadA peptide 8 were absent, while PorA P1.7–2,4 was found in one isolate (1.4%). Mutated penA alleles were present in 73.7% of the isolates. Major peptides (PorA, PorB, FetA, NHBA, fHbp) were correlated with clonal complexes and serogroups. Conclusion This is the first genomic study of Neisseria meningitidis conducted in Paraguay, enabling a novel understanding of the genetic characteristics of invasive isolates. The generation of genomic data is essential for monitoring the spread of circulating lineages or clones that may alter their antigenic profiles to evade host immune responses.

Acinetobacter baumannii is a major nosocomial pathogen worldwide and, specifically, in Latin America. Genomic epidemiology has been instrumental in determining the transmission dynamics of A. baumannii in many countries of the world, yet some Latin American countries have conducted no genomic epidemiology studies. Here, we conduct the first genomic epidemiology study about this pathogen in Paraguay. We sequenced 43 isolates from a big tertiary hospital in Paraguay collected from different wards in 2021 and 2022. Our genomic epidemiology analyses, including almost 200 genomes and considering the main international clones (ICs), show that IC1, IC2, IC4, IC5 and IC7 were found in the hospital. We found novel genetic variation (3 novel Sequence Types as per the Oxford MLST scheme and one as per the Pasteur scheme) within IC7. Antibiotic susceptibility tests show that all but one of the Paraguayan isolates were resistant to carbapenems. Notably, 98% were classified as multidrug-resistant. We detected plasmids in almost all the Paraguayan isolates. Furthermore, we detected cases of recent horizontal transfer of important antibiotic-resistance genes between different ICs. On a general note, our findings highlight polyclonal spreading across different hospital wards and horizontal transfer of clinically relevant antibiotic-resistance genes among the different clones. On a more local note, this is the first genomic epidemiology study of A. baumannii in Paraguay and will be a reference point for future studies in the country and the region.

Introducción: la diseminación de bacterias gramnegativas resistentes a carbapenémicos representa una causa importante de morbi-mortalidad, siendo una amenaza creciente para la salud pública y de gran preocupación en el mundo. Aunque la resistencia a carbapenémicos puede ser debida a varios mecanismos, el más relevante, clínica y epidemiológicamente, es por producción de enzimas. Objetivos: caracterizar fenotípica y genotípicamente carbapenemasas producidas por bacilos gramnegativos de importancia clínica aislados en hospitales de Paraguay en el año 2022 y evaluar la susceptibilidad a colistina. Metodología: estudio multicéntrico, retrospectivo, realizado en 1226 cepas remitidas al Laboratorio Central durante el año 2022 para su caracterización fenotípica y genotípica. Fueron realizados estudios de identificación (métodos convencionales), susceptibilidad a colistina (microdilución en caldo), y de confirmación de genes de resistencia (moleculares). Resultados: de las 1226 cepas estudiadas, 629 (51 %) correspondieron a no fermentadores (89 % Acinetobacter spp.) y 597 (49 %) a fermentadores (74 % Klebsiella pneumoniae). Las carbapenemasas confirmadas en A. baumannii fueron: OXA-23(94,9 %), NDM (3,1 %), OXA-23 + NDM (1,8 %) y OXA-23+NDM+OXA-58 (0,2 %); en K. pneumoniae: NDM (84,5 %), KPC (11,7 %), KPC+NDM (3,7 %) y NDM+OXA-48like (0,2 %); y en P. aeruginosa la prevalente fue NDM (50,9 %). La resistencia asociada a colistina, fue encontrada principalmente en K. pneumoniae (24 %). Conclusión: en nuestro país es endémica la circulación de bacterias productoras de carbapenemasa. La coproducción de estas enzimas está confirmada. NDM es la prevalente en Enterobacterales y P. aeruginosa y OXA-23 en A. baumannii. La alta resistencia asociada a colistina en K. pneumoniae hace imperiosa la necesidad de contar con nuevos antimicrobianos más efectivos para el tratamiento de las infecciones.

Introduction. Streptococcus pneumoniae remains a major cause of mortality and morbidity worldwide in children <5 years of age, even with advances in vaccination programmes. Hypothesis/Gap Statement. Reviewing and reporting trends in the distribution of pneumococcal serotypes and antimicrobial resistance in Paraguay will be useful for decision-making in public health. Aim. This study analysed the serotype distribution and antimicrobial resistance of S. pneumoniae and the characteristics of pneumococcal disease in children <5 years old before and after the introduction of pneumococcal conjugate vaccines (PCVs). Methodology. A total of 885 isolates and 278 S. pneumoniae PCR-positive clinical specimens were referred to the Central Laboratory of Public Health (LCSP) within the meningitis and pneumonia laboratory based-surveillance network in the period 2006–2020. Conventional and molecular microbiological techniques were used for confirmation and characterization. Results. We identified 563 cases of pneumococcal disease in the pre-vaccination period, 325 cases in the post-PCV10 period and 275 cases in the post-PCV13 period. The serotypes covered by PCV10 decreased from 78.6–6.5 %. However, additional serotypes covered by PCV13 increased from 6.6–57.5% and non-PCV13 serotypes increased from 14.8–36.0 % (P<0.001) in the post-PCV13 period. In cases of meningitis, the rate of resistance to penicillin decreased after the introduction of conjugate vaccines. No resistance to ceftriaxone was found in any period. In cases without meningitis, the rate of resistance to penicillin and ceftriaxone decreased slightly. However, the rate of resistance to erythromycin and tetracycline increased and that to trimethoprim–sulfamethoxazole (SXT) decreased in the post-PCV13 period compared to the pre-PCV period. The multidrug resistance rate was 8.5 %. Conclusion. A change in the circulating serotypes and antimicrobial resistance to certain antibiotics was observed. Non-vaccine serotype circulation and multidrug resistance may compromise the success of the conjugate vaccines.

La infección por Clostridioides difficile es una de las principales causas de diarrea nosocomial en hospitales del mundo, asociada a antibióticos de amplio espectro. Estudio descriptivo, retrospectivo, de corte transverso, de tipo censal. Se estudiaron 281 muestras de pacientes hospitalizados con la infección, se analizaron características socio-demográficas, clínicas y se caracterizó molecularmente al patógeno. Como resultado, se obtuvieron pacientes con la infección con una mediana de edad de 64 años siendo el 61,5 % del sexo masculino. El promedio de presentación del cuadro diarreico fue de 5 días, con tratamiento antimicrobiano de 8 días e internación de 15 días. El 94% tuvo tratamiento antimicrobiano previo, y el 6% estuvo expuesto a algún factor de riesgo. Los antimicrobianos más utilizados solos o en combinación fueron betalactámicos, fluoroquinolonas, vancomicina y carbapenémicos. Las áreas de internación con mayor frecuencia de presentación de la infección fueron las unidades de Clínica Médica, Traumatología, Geriatría y Unidad de Terapia Intensiva. La prevalencia de C. difficile toxigénico fue de 14%, y de esta frecuencia el 100% presentó toxinas TcdA y TcdB, con ausencia de toxinas binarias y deleción del gen tcdC. Se constató la presencia grupos clonales en la misma unidad de internación y misma institución de salud. El 100% de las cepas resultaron susceptibles a los antibióticos de elección para la infección. La prevalencia de la infección y presencia de perfiles clonales detectadas revelan la necesidad de un mejoramiento en el sistema de control de infecciones, así como del fortalecimiento y vigilancia de la resistencia antimicrobiana.

Los trastornos hipertensivos del embarazo forman parte de un conjunto de alteraciones vasculares que complican el curso de un embarazo y junto con las infecciones y hemorragias ocupan las principales causas de mortalidad materna y perinatal en todo el mundo. El estudio se realizó con el siguiente objetivo: Conocer las complicaciones materno – fetales más frecuentes en embarazadas con hipertensión arterial en el servicio de Ginecología. El diseño aplicado fue cuantitativo, observacional, descriptivo y retrospectivo de corte transversal. Para la obtención de los resultados, se incluyó un total de 54 pacientes con una media de edades de 26,6 ± 7,3 años, el 52% proviene del área rural, en el 24% se constató que el número de controles prenatales fueron suficientes. Se constató como complicaciones prevalentes en un 31% hipertonía uterina, 26% abruptio placentae, mortalidad fetal 2%. En conclusión, se ha constatado que las complicaciones materno-fetales con mayor frecuencia han sido la hipertonía uterina, retraso del crecimiento uterino y la Policitemia en recién nacidos, presentándose con mayor frecuencia en mujeres de 20 a 24 años con nivel educativo bajo y de procedencia rural.

Streptococcus pneumoniae is a cause of invasive diseases such as pneumonia, meningitis, and other serious infections among children and adults in Paraguay. This study was conducted to establish S. pneumoniae baseline prevalence, serotype distribution, and antibiotic resistance patterns in healthy children aged 2 to 59 months and adults ≥60 years of age prior to the introduction of PCV10 in the national childhood immunization program in Paraguay. Between April and July 2012, a total of 1444 nasopharyngeal swabs were collected, 718 from children aged 2 to 59 months and 726 from adults ≥60 years of age. The pneumococcal isolation, serotyping, and antibiotic susceptibility testing were performed using standard tests. Pneumococcal colonization prevalence was 34.1% (245/718) in children and 3.3% (24/726) in adults. The most frequent pneumococcal vaccine-types (VT) detected in the children were 6B (42/245), 19F (32/245), 14 (17/245), and 23F (20/245). Carriage prevalence with PCV10 serotypes was 50.6% (124/245) and PCV13 was 59.5% (146/245). Among colonized adults, prevalence of PCV10 and PCV13 serotypes were 29.1% (7/24) and 41.6% (10/24), respectively. Colonized children were more likely to share a bedroom, have a history of respiratory infection or pneumococcal infection compared to non-colonized children. no associations were found in adults. However, no significant associations were found in children and neither in adults. Vaccine-type pneumococcal colonization was highly prevalent in children and rare in adults in Paraguay prior to vaccine introduction, supporting the introduction of PCV10 in the country in 2012. These data will be useful to evaluate the impact of PCV introduction in the country.

Introducción: La determinación de niveles séricos de micronutrientes de los niños menores de 5 años, es un requerimiento básico para establecer la prevalencia de deficiencias nutricionales de la población infantil y es una estrategia útil para incentivar a Salud Pública para que tome medidas en cuanto a aplicación y/o modificación de las Políticas Alimentarias Nacionales. Objetivo: Determinar los niveles séricos de cobre, hierro y zinc en niños paraguayos menores de 5 años. Materiales y Métodos: Estudio observacional, descriptivo y de corte transversal. Se procesaron las muestras de sangre de 1.441 niños menores de 5 años de edad que provenían de los Departamentos de Alto Paraná, Caaguazú, Central y de la capital de Paraguay. Se realizaron hemogramas y se determinaron las concentraciones séricas de albúmina, cobre, ferritina y zinc, de todas las muestras. Resultados: Los niños tuvieron una edad promedio de 3 años y 3 meses, fueron 52,74% de sexo masculino y 47,26% de sexo femenino. La prevalencia de anemia fue de 45,25% y la prevalencia de hipoalbuminemia fue de 20,65%. Se detectaron deficiencias de cobre en 14,03%, de ferritina en 6,98% y de zinc en 43,62%, de los niños. Conclusión: Los resultados de este estudio avalan la necesidad de ampliar la cobertura del Programa Alimentario Nutricional Integral (PANI), de plantearse si se deben ajustar las cantidades de minerales y vitaminas de la fórmula nutricional del Programa y de mejorar el seguimiento de los controles prenatales de las madres.