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Prompt and precise identification of carbapenemase-producing organisms is crucial for guiding clinical antibiotic treatments and limiting transmission. Here, we propose modifying the Blue Carba test (BCT) and Carba NP-direct (CNPd) to identify molecular carbapenemase classes, including dual carbapenemase strains, by adding specific Class A and Class B inhibitors. We tested 171 carbapenemase-producing Gram-negative bacilli strains-21 in Class A (KPC, NMC, SME), 58 in Class B (IMP, VIM, NDM, SPM), and 92 with dual carbapenemase production (KPC+NDM, KPC+IMP, KPC+VIM), all previously positive with BCT or CNPd. We also included 13 carbapenemase non-producers. ß-lactamases were previously characterized by PCR. The improved BCT/CNPd methods detect imipenem hydrolysis from an imipenem-cilastatin solution, using pH indicators and Class A (avibactam) and/or Class B (EDTA) inhibitors. Results were interpreted visually based on color changes. CNPd achieved 99.4% sensitivity and 100% specificity in categorizing carbapenemases, while BCT had 91.8% sensitivity and 100% specificity. Performance varied by carbapenemase classes: both tests classified all Class A-producing strains. For Class B, the CNP test identified 57/58 strains (98.3%), whereas the BCT test, 45/58 strains (77.6%), with non-fermenters posing the greatest detection challenge. For Classes A plus B dual producers, both tests performed exceptionally well, with only one indeterminate strain for the BCT. The statistical comparison showed both methods had similar times to a positive result, with differences based on the carbapenemase class or bacterial group involved. This improved assay rapidly distinguishes major Class A or Class B carbapenemase producers among Gram-negative bacilli, including dual-class combinations, in less than 2 hours. IMPORTANCE: Rapid and accurate identification of carbapenemase-producing organisms is of vital importance in guiding appropriate clinical antibiotic treatments and curbing their transmission. The emergence of negative bacilli carrying multiple carbapenemase combinations during and after the severe acute respiratory syndrome coronavirus 2 pandemic has posed a challenge to the conventional biochemical tests typically used to determine the specific carbapenemase type in the isolated strains. Several initiatives have aimed to enhance colorimetric methods, enabling them to independently identify the presence of Class A or Class B carbapenemases. Notably, no previous efforts have been made to distinguish both classes simultaneously. Additionally, these modifications have struggled to differentiate between carriers of multiple carbapenemases, a common occurrence in many Latin American countries. In this study, we introduced specific Class A and Class B carbapenemase inhibitors into the Blue Carba test (BCT) and Carba NP-direct (CNP) colorimetric assays to identify the type of carbapenemase, even in cases of multiple carbapenemase producers within these classes. These updated assays demonstrated exceptional sensitivity and specificity (≥ 90%) all within a rapid turnaround time of under 2 hours, typically completed in just 45 minutes. These in-house enhancements to the BCT and CNP assays present a rapid, straightforward, and cost-effective approach to determining the primary carbapenemase classes. They could serve as a viable alternative to molecular biology or immuno-chromatography techniques, acting as an initial diagnostic step in the process.

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Diabetes mellitus (DM) is a chronic systemic disease characterized by a multifactorial nature, which may lead to several macro and microvascular complications. Diabetic retinopathy (DR) is one of the most severe microvascular complications of DM, which can result in permanent blindness. The mechanisms involved in the pathogenesis of DR are multiple and still poorly understood. Factors such as dysregulation of vascular regeneration, oxidative and hyperosmolar stress in addition to inflammatory processes have been associated with the pathogenesis of DR. Furthermore, compelling evidence shows that components of the immune system, including the complement system, play a relevant role in the development of the disease. Studies suggest that high concentrations of mannose-binding lectin (MBL), an essential component of the complement lectin pathway, may contribute to the development of DR in patients with DM. This review provides an update on the possible role of the complement system, specifically the lectin pathway, in the pathogenesis of DR and discusses the potential of MBL as a non-invasive biomarker for both, the presence and severity of DR, in addition to its potential as a therapeutic target for intervention strategies.

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BACKGROUND: The process of tissue injury in coronary artery disease (CAD) has been associated with activation of the complement system, partly due to the action of mannose-binding lectin (MBL) and C3, which are expressed in atherosclerotic lesions. OBJECTIVE: The aim of this study was to evaluate the serum levels of MBL and C3 in patients with CAD and to compare them with healthy controls. Additionally, we aim to assess the correlation between MBL and C3 levels and cardiometabolic parameters. METHODS: MBL and C3 serum concentration were determined by ELISA and immunoturbidimetry, respectively, in up to 119 patients undergoing coronary angiography for CAD evaluation, comprising 48 individuals diagnosed with acute myocardial infarction (MI) and 71 without MI. A total of 93 paired healthy controls were included in the study. RESULTS: Individuals with CAD had MBL serum concentration higher than controls (p = .002), regardless of the presence of MI (p = .006). In addition, high concentration of MBL (>2000 ng/mL) was more frequent in patients with CAD (p = .007; OR = 2.6; 95% CI = 1.3-5.1). C3 levels were not significantly associated with any of the patient groups but were positively correlated with cardiometabolic parameters such as body mass index (BMI) and triglycerides levels. CONCLUSIONS: Higher concentrations of MBL were found to be associated with CAD, whereas C3 levels were found to be associated with cardiovascular risk factors.

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Introduction: Mannose-binding lectin (MBL) promotes opsonization, favoring phagocytosis and activation of the complement system in response to different microorganisms, and may influence the synthesis of inflammatory cytokines. This study investigated the association of MBL2 gene polymorphisms with the plasma levels of MBL and inflammatory cytokines in COVID-19. Methods: Blood samples from 385 individuals (208 with acute COVID-19 and 117 post-COVID-19) were subjected to real-time PCR genotyping. Plasma measurements of MBL and cytokines were performed by enzyme-linked immunosorbent assay and flow cytometry, respectively. Results: The frequencies of the polymorphic MBL2 genotype (OO) and allele (O) were higher in patients with severe COVID-19 (p< 0.05). The polymorphic genotypes (AO and OO) were associated with lower MBL levels (p< 0.05). IL-6 and TNF-α were higher in patients with low MBL and severe COVID-19 (p< 0.05). No association of polymorphisms, MBL levels, or cytokine levels with long COVID was observed. Discussion: The results suggest that, besides MBL2 polymorphisms promoting a reduction in MBL levels and therefore in its function, they may also contribute to the development of a more intense inflammatory process responsible for the severity of COVID-19.

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Pseudomonas aeruginosa and species of Acinetobacter calcoaceticus-baumanii complex are multiresistant intrahospital opportunistic pathogens, able to acquire carbapenemases and produce outbreaks with high morbidity and mortality. Pseudomonas putida has also emerged with similar characteristics. The aim of this research was to characterize the Metallo-ß-lactamases (MBLs) detected by surveillance in Paraguay in the first 5 years of their circulation in hospitals. The coexistence of KPC and OXA-type carbapenemases was also investigated. 70 MBL-producing strains from inpatients were detected from clinical samples and rectal swab from 11 hospitals. The strains were identified by manual, automated, and molecular methods. Antimicrobial susceptibility was studied by Kirby-Bauer and automated methods, while colistin susceptibility was determined by broth macrodilution. MBLs were investigated by synergy with EDTA against carbapenems and PCR, and their variants by sequencing. KPC and OXA-carbapenemases were investigated by PCR. Clonality was studied by pulsed-field gel electrophoresis (PFGE). The results demonstrated the circulation of blaVIM-2 (60%), blaNDM-1 (36%), and blaIMP-18 (4%). The MBL-producing species were P. putida (45.7%), P. aeruginosa (17.2%), A. baumannii (24.3%), A. pittii (5.7%), A. nosocomialis, (4.3%) A. haemolyticus (1.4%), and A. bereziniae (1.4%). PFGE analysis showed one dominant clone for A. baumannii, a predominant clone for half of the strains of P. aeruginosa, and a polyclonal spread for P. putida. In the first 5 years of circulation in Paraguay, MBLs were disseminated as unique variants per genotype, appeared only in Pseudomonas spp. and Acinetobacter spp., probably through horizontal transmission between species and vertical by some successful clones.

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Quantum dots (QDs) have stood out as nanotools for glycobiology due to their photostability and ability to be combined with lectins. Mannose-binding lectin (MBL) is involved in the innate immune system and plays important roles in the activation of the complement cascade, opsonization, and elimination of apoptotic and microbial cells. Herein, adsorption and covalent coupling strategies were evaluated to conjugate QDs to a recombinant human MBL (rhMBL). The most efficient nanoprobe was selected by evaluating the conjugate ability to labelCandida albicansyeasts by flow cytometry. The QDs-rhMBL conjugate obtained by adsorption at pH 6.0 was the most efficient, labelingca.100% of cells with the highest median fluorescence intensity. The conjugation was also supported by Fourier transform infrared spectroscopy, zeta potential, and size analyses.C. albicanslabeling was calcium-dependent; 12% and <1% of cells were labeled in buffers without calcium and containing EDTA, respectively. The conjugate promoted specific labeling (based on cluster effect) since, after inhibition with mannan, there was a reduction of 80% in cell labeling, which did not occur with methyl-α-D-mannopyranoside monosaccharide. Conjugates maintained colloidal stability, bright fluorescence, and biological activity for at least 8 months. Therefore, QDs-rhMBL conjugates are promising nanotools to elucidate the roles of MBL in biological processes.

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BACKGROUND: The mannose-binding lectin (MBL) plays an important role in innate immunity. Genetically determined variations in serum levels of MBL may influence the susceptibility and clinical outcome of dengue infection in early life. METHODS: We investigated the MBL2 gene polymorphisms and serum levels of MBL (total and functional) in children with asymptomatic (n=17) and symptomatic (n=29) primary dengue infections and age-matched uninfected children (n=84) enrolled in a birth cohort with dengue in Brazil. Polymorphisms of the MBL2 gene were assessed by reverse transcription-polymerase chain reaction (RT-PCR), whereas the enzyme-linked immunosorbent assay (ELISA) was used to quantify serum levels of MBL. RESULTS: We found that the X allele and YX genotype in the MBL2 were more frequent in the dengue cases than in the control group. Likewise, the LXPA haplotype was exclusively found in dengue cases, thus probably related to dengue infection in our setting. Moreover, we found a higher frequency of the O allele and AO genotype in the control group. Serum levels of total and functional MBL were higher in dengue naïve infants than in dengue cases. CONCLUSIONS: MBL2 variants related to lower production of serum MBL were associated with dengue infection in infants, whereas intermediate to high levels of total and functional serum MBL were associated with protection against dengue infection. These findings highlight the role of MBL2 variants and serum levels of MBL in the susceptibility of children to dengue disease at early ages.

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Resumen El COVID-19 es una patología producida por el SARS-CoV-2, virus de carácter zoonótico capaz de producir patologías multiorgánicas. La sintomatología que produce es variada. Ante la infección algunos pacientes presentan condiciones de gravedad. Los estudios han demostrado que el rol genético tiene gran afluencia sobre la respuesta ante la infección. El objetivo de investigación es detallar los genes que están implicados en la gravedad de la infección por SARS-CoV- 2. Metodología . Se realizó una revisión sistemática, con base a la búsqueda y análisis de artículos originales en bases de datos de alto impacto como PudMed, Google Académico, Scopus, Taylor & Francis, ProQuest SciencieDirect; se utilizaron operadores booleanos, criterios de inclusión y exclusión con el objetivo de obtener información precisa. Los genes de inmunidad como el HLA, ACE2 y TMPRSS2 están directamente involucrados con la gravedad de la infección por SARS-CoV- 2. Los polimorfismos de los genes del polyQ del receptor de andrógenos, factor ABO coadyuvan a un deterioro del estado patológico como consecuencia de la COVID-19. Conclusión. Los estudios demostraron que existen genes involucrados en la gravedad ante la infección de SARS -CoV-2, pues mencionan que los polimorfismos de los genes; HLA, del polyQ del receptor de andrógenos y factor ABO producen susceptibilidad ante el COVID-19. Así mismo los genes ACE2 y TMPRSS2 intervienen en el ingreso y expansión del virus. En las diversas razas existen variantes de los genes CCL2 y MBL lo que indica que algunas poblaciones son más susceptibles que otras.

Abstract COVID-19 is a pathology caused by SARS-CoV-2, a zoonotic virus capable of producing multi-organ pathologies. The symptomatology it produces is varied. Some patients present severe conditions after infection. Studies have shown that the genetic role has a great influence on the response to infection. Methodology . A systematic review was carried out, based on the search and analysis of original articles in high impact databases such as PudMed, Google Scholar, Scopus, Taylor & Francis, ProQuest SciencieDirect; Boolean operators, inclusion and exclusion criteria were used in order to obtain accurate information. Immunity genes such as HLA, ACE2 and TMPRSS2 are directly involved with the severity of SARS-CoV- 2 infection. Polymorphisms of androgen receptor polyQ genes, ABO factor contribute to a deterioration of the pathological state as a consequence of COVID-19. Conclusion . The studies demonstrated that there are genes involved in the severity of SARS-CoV-2 infection, since they mention that polymorphisms of the HLA, androgen receptor polyQ and ABO factor genes produce susceptibility to COVID-19. Likewise, ACE2 and TMPRSS2 genes intervene in the entry and expansion of the virus. In the different breeds there are variants of the CCL2 and MBL genes, which indicates that some populations are more susceptible than others.

Resumo COVID-19 é uma patologia causada pelo SARS-CoV-2, um vírus zoonótico capaz de produzir patologias multiorganismos. Os sintomas que ela produz são variados. Alguns pacientes se apresentam com condições severas após a infecção. Estudos demonstraram que o papel da genética desempenha um papel importante na resposta à infecção. O objetivo desta pesquisa é detalhar os genes que estão envolvidos na gravidade da infecção pelo SARS-CoV- 2. Metodologia. Foi realizada uma revisão sistemática, baseada na busca e análise de artigos originais em bancos de dados de alto impacto como PudMed, Google Scholar, Scopus, Taylor & Francis, ProQuest SciencieDirect; operadores booleanos, critérios de inclusão e exclusão foram utilizados para obter informações precisas. Resultados. Os genes de imunidade como HLA, ACE2 e TMPRSS2 estão diretamente envolvidos na gravidade da infecção pelo SARS-CoV- 2. Os polimorfismos dos genes receptores de androgênio polyQ, fator ABO contribuem para uma deterioração do estado patológico como conseqüência da COVID-19. Conclusão. Os estudos demonstraram que existem genes envolvidos na gravidade da infecção pelo SRA-CoV-2, pois mencionam que os polimorfismos dos genes HLA, androgênio receptor policarbonato e fator ABO produzem suscetibilidade à COVID-19. Os genes ACE2 e TMPRSS2 também estão envolvidos na entrada e propagação do vírus. Existem variantes dos genes CCL2 e MBL nas diferentes raças, indicando que algumas populações são mais suscetíveis do que outras.

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En salud pública a nivel mundial, la producción de carbapenemasas es actualmente el mayor problema de resistencia antimicrobiana. El objetivo de este estudio fue caracterizar las carbapenemasas en enterobacterias en pacientes que acudieron al Hospital General San Juan de Dios de la ciudad de Guatemala y determinar servicios hospitalarios y tipos de muestras más frecuentes. Se usaron datos de 2014 y 2015 del área de bacteriología del hospital; se realizó una revisión sistemática, selección, ordenamiento y cálculo de frecuencias y porcentajes. En 2014, 165/165 (100 %) de las carbapenemasas fueron de tipo metalo-ß-lactamasas (MBL); en 2015, 90/118 (76 %) MBL y 28/118 (24 %) Klebsiella pneumoniae carbapenemasa (KPC). Klebsiella pneumoniae fue la enterobacteria productora de carbapenemasas (CPE) aislada con más frecuencia, 134/165 (81 %) en 2014 y 82/118 (69 %) en 2015. En 2014 la unidad de cuidados intensivos de neonatos obtuvo el mayor porcentaje de aislamientos de CPE, 30/165 (18 %); en 2015, medicina de hombres fue el servicio con el mayor porcentaje de CPE, 13/118 (11 %). El tipo de muestra más frecuente en 2014 fue sangre, 67/165 (41 %); en el 2015 fue orina, 31/118 (26 %). Los resultados evidencian la persistencia de carbapenemasas tipo MBL y la aparición de nuevos tipos, específicamente carbapenemasas tipo KPC, que destacan la necesidad de actuar urgentemente ante el riesgo que suponen para la salud de la población.

In public health worldwide, carbapenemase production is currently the biggest problem of antimicrobial resistance. The objective of this study was to characterize carbapenemases in Enterobacteriaceae of patients who attended the San Juan de Dios General Hospital in Guatemala City and to determine hospital services and types of samples more frequent. Data from 2014 and 2015 of the bacteriology department of the hospital were used; a systematic review, selection, ordering and calculation of frequencies and percentages was conducted. In 2014, 165/165 (100 %) of the carbapenemases were metallo-ß-lactamases (MBL); in 2015, 90/118 (76 %) MBL and 28/118 (24 %) Klebsiella pneumoniae carbapenemase (KPC). Klebsiella pneumoniae was the carbapenemases-producing Enterobacteriaceae (CPE) most frequently isolated, 134/165 (81 %) in 2014 and 82/118 (69 %) in 2015. In 2014 the neonatal intensive care unit obtained the highest percentage in CPE, 30/165 (18 %); in 2015, men's medicine was the service with the highest percentage of carbapenemases, 11/138 (11 %). The most frequent type of sample in 2014 was blood, 67/165 (41 %). In 2015 it was urine, 31/118 (26 %). The results obtained highlight the persistence of MBL-type carbapenemases and the appearance of new types of carbapenemases, specifically KPC. These results underline the need to act urgently in Guatemala in the face of the problems that carbapenemases-producing Enterobacteriaceae pose for the health of the population.

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Introducción: El propósito del estudio es determinar en los urocultivos, la prevalencia de los mecanismos enzimáticos de resistencia encontrados in vitro. Materiales y métodos: Se realizó un estudio retrospectivo, de ambos sexos, mayores de 18 años, que acudieron al Consultorio Externo de Clínica Médica y Urgencias por síntomas de infección urinaria. Se incluyeron todos los urocultivos en los que se aislaron uropatógenos con recuento ≥ 105 UFC/mL. Se excluyeron los urocultivos polimicrobianos, los que no contaban con antibiograma o aquellos con datos clínicos incompletos. Resultados: Se identificaron 1031 urocultivos que cumplieron con los criterios establecidos para la realización del estudio. El 56% correspondió al sexo femenino y el 43% al masculino. La edad media de las mujeres fue de 52± 20 años y el de los hombres fue de 62±16 años. Los uropatógenos más frecuentes fueron Escherichia coli 553 (52% en promedio) seguida de Klebsiella pneumoniae con 148 (14% en promedio). Urocultivos de varones: El principal mecanismo de resistencia de Escherichia coli fueron las BLEE, 55 aislamientos (91%); seguida de las MBL, 3 aislamientos (5%) y KPC, 2 aislamientos (3%). En Klebsiella pneumoniae en 53 aislamientos se puedo observar: BLEE, 31 aislamientos (58%); seguida de las KPC 13 aislamientos (25%) y MBL, 9 aislamientos en (16%). Urocultivos en mujeres: Las enzimas de Escherichia coli fueron 81 aislamientos, de los cuales fueron BLEE, 79 aislamientos (97%); seguido de las KPC, 1 aislamiento (1%) y las MBL, 1 aislamiento (1%). En Klebsiella pneumoniae se pudo observar los siguientes mecanismos enzimáticos en base a 35 aislamientos; BLEE, 19 aislamientos (54%), seguida de las KPC, 12 aislamientos (34%) y por último, MBL, 4 aislamientos (13%). Conclusión: En las IVU de nuestro estudio, Escherichia coli y Klebsiella pneumoniae fueron las principales bacterias que originan resistencia a los antibióticos y la BLEE fue la enzima más frecuentemente identificada en ambos sexos.

Introduction: The objective of this study was to assess frequency of enzymatic resistance mechanisms isolated from community urinary tract infections (UTI) determined in vitro in urine cultures. Objectives: This is a retrospective study, a total of 1031 urine samples were included from patients with urinary tract infection who had consulted at the Outpatient Clinic and Emergencies Services. The following information was recorded, age, sex, urine sample. All urine cultures in which pathogens with a count of ≥ 105 CFU / mL were included. Were excluded polymicrobial urine cultures, those without an antibiogram or those with incomplete clinical data. Results: A total of 1031 urine samples met inclusion criteria, 56% of patients were female and 43% male. The mean age of the women was 52 ± 20 years and in men was 62 ± 16 years. 553 (52%) E. coli and 148 (14%) Klebsiella strains were isolated from community samples. Male urine cultures: The main resistance mechanism of Escherichia coli was ESBLs, 55 isolates (91%); followed by MBL, 3 isolates (5%) and KPC, 2 isolates (3%). In Klebsiella pneumoniae (53 isolates); ESBL, 31 isolates (58%); followed by KPC 13 isolates (25%) and MBL, 9 isolates in (16%). Female urine culture: Escherichia coli enzymes 81 isolates, of which ESBLs were 79 isolates (97%); followed by KPC, 1 isolate (1%) and MBL, 1 isolate (1%). In Klebsiella pneumoniae the following enzymatic mechanisms could be observed based on 35 isolates; ESBL, 19 isolates (54%), followed by KPCs, 12 isolates (34%) and finally, MBL, 4 isolates (13%). Conclusion: The result of our study showed high prevalence of Escherichia coli and Klebsiella pneumoniae causing resistance to antibiotics in culture bacteria from urine samples of patients with UTI, and ESBL was the main ß-lactamase resistance mechanism in Klebsiella and E. coli isolates in both male and female.

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