ABSTRACT Objective The establishment of reference values for a subset of leukocytes is common in clinical practice, and ethnic variations are strongly associated with disease development. In Brazil, indigenous people are vulnerable to infections, and few studies have described the health and disease conditions of this population. This study aimed to provide reference values for immunological cell subsets in indigenous Brazilians living in the state of Mato Grosso do Sul. Methods Flow cytometry and 4-color combinations of monoclonal antibodies were used to characterize cells. A total of 115 healthy adults, mostly females (72%), were included in the study. The results are presented as mean and median (2.5%-97.5% percentiles) for T and B lymphocytes, CD4+ T cells, CD8+ T cells, Natural Killer cells, monocytes, and dendritic cells, providing an average immunological profile for the population in question. Results The relative medians of CD3+, CD4+, and CD8+ T cells were significantly higher in women than in men in a healthy indigenous population. Conclusion To our knowledge, cell reference data from indigenous Brazilians are unknown in the literature. The immune cell results presented in this pioneering study will contribute to the clinical and laboratory evaluation of the Brazilian indigenous population, especially given the important differences when compared with other Brazilian ethnic groups.

ABSTRACT Polymyxin antibiotics are disfavored owing to their potential clinical toxicity, especially nephrotoxicity. However, the dry antibiotic development pipeline, together with the increasing global prevalence of infections caused by multidrug-resistant (MDR) gram-negative bacteria, have renewed clinical interest in these polypeptide antibiotics. This review highlights the current information regarding the mechanisms of resistance to polymyxins and their molecular epidemiology. Knowledge of the resistance mechanisms and epidemiology of these pathogens is critical for the development of novel antibacterial agents and rapid treatment choices.

ABSTRACT Background: Carbapenem-resistant Acinetobacter baumannii (CRAB) is a growing threat to public health. Methods: A 3-year retrospective study was conducted to evaluate the prevalence and lethality of multidrug-resistant (MDR) A. baumannii isolated from Brazilian patients. Results: In this study, 219 Acinetobacter baumannii isolates were identified, of which 70.8% (155/219) were isolated from patients hospitalized in intensive care units. Of these, 57.4% (n = 89/155) were assessed, of which 92.1% (82/89) were carbapenem-resistant, and 49 were classified as infected. The lethality rate was 79.6% (39/49). Conclusions: We highlight the need of an effective epidemiological surveillance measure to contain the dissemination of CRAB in the hospital environment.

ABSTRACT Syphilis is caused by the bacterium Treponema pallidum. The diagnosis is based on clinical data and serological analysis; however, the sensitivity and specificity of such tests may vary depending on the type of test and stage of the infection. In order to overcome this premise, this study utilized the polymerase chain reaction (PCR) for the detection of T. pallidum DNA in whole blood samples of patients with syphilis. The blood samples from patients with or without symptoms of syphilis, but with positive results in enzyme-linked immunosorbent assay (ELISA), were included in this study. A venereal disease research laboratory (VDRL) test was performed for all collected sera samples. For PCR, the T. pallidum DNA was extracted from the collected blood samples and a specific primer set was designed to amplify 131 nucleotides of polA (Tp0105). The specificity of the primers was evaluated with the DNA of 17 different pathogens. From a total of 314 blood samples reactive in ELISA, 58.2% (183/314) of the samples were reactive in the VDRL test. In the PCR, 54% (168/314) of the ELISA-reactive samples were positive. In both tests (VDRL and PCR) 104 samples were positive. Of 104 positive samples for both tests, 71 were at the latent stage. Based on these results, it can be concluded that PCR with the designed set of primers can be utilized as a diagnostic method for T. pallidum detection in blood samples of patients with syphilis, especially those with latent infection. In addition, it can be utilized as a supplement for serological methods to improve the diagnosis of syphilis.

ABSTRACT This cross-sectional observational study that describes the epidemiological data of the first year of the COVID-19 pandemic in the Mato Grosso do Sul State, aimed to demonstrate the differences between indigenous and non-indigenous populations, characterize confirmed cases of COVID-19 according to risk factors related to ethnicity, comorbidities and their evolution and to verify the challenges in facing the disease in Brazil. SIVEP-Gripe and E-SUS-VE, a nationwide surveillance database in Brazil, from March 2020 to March 2021 in Mato Grosso do Sul state, were used to compare survivors and non-survivors from indigenous and non-indigenous populations and the epidemiological incidence curves of these populations. A total of 176,478, including 5,299 indigenous people, were confirmed. Among the indigenous population, 52.5% (confidence interval [CI] 51.2-53.9) were women, 38% (CI 36.7-39.4) were 20-39 years old, 56.7% were diagnosed by rapid antibody tests, 12.3% (CI 95%:11.5-13.2) had at least one comorbidity, and 5.3% (CI 95%:4.7–5.9) were hospitalized. In the non-indigenous patients, 56.8% were confirmed using RT-PCR, 4.4% (CI 95%:4.3-4.5) had at least one comorbidity, and 8.0% (CI 95%:7.9-8.2) were hospitalized. The majority of non-survivors were ≥60 years old (65.1% indigenous vs. 74.1% non-indigenous). The mortality in indigenous people was more than three times higher (11% vs. 2.9%). Indigenous people had a lower proportion of RT-PCR diagnoses; deaths were more frequent in younger patients and were less likely to be admitted to hospital. Mass vaccination may have controlled the incidence and mortality associated with COVID-19 in this population during the period of increased viral circulation.

ABSTRACT Syphilis, an infectious disease considered a global public health concern, can cause stillbirths and neonatal deaths. This highlights the importance of continuous surveillance studies among women of reproductive age. A cross-sectional study was carried out to analyze the prevalence and risk factors associated with Treponema pallidum infection in women assisted by primary health care units in Dourados, a city located in Mato Grosso do Sul State, Brazil, which borders Paraguay. A questionnaire was applied to a population-based sample, blood samples were collected for syphilis testing and multivariable analyses were performed to screen associations with T. pallidum infection. The prevalence of T. pallidum infection was 6.04%. Bivariate analysis showed that women referring multiple sexual partners (c2: 6.97 [p=0.014]), income less 2 minimal wages (c2: 15.93 [p=0.003]), who did not have high school (c2: 12.64 [p=0.005]), and reporting history of STIs (c2: 7.30 [p=0.018]) are more likely to have syphilis. In the multivariate analysis, a highest prevalence ratio was observed in women with income less than 2 minimal wages (PR: 0.96 [95% CI: 0.85 - 0.97]), and who did not have high school (PR: 0.94 [95% CI: 0.90 - 0.98]). In addition, 80% of the women reported irregular use of condoms and 63.89% declared having sexual intercourses with multiple partners, which creates more opportunities for the transmission of the infection. These results highlight the need for healthcare systems to implement initiatives to monitor syphilis screening and the commitment of patients and their sexual partners to the treatment in order to achieve a decrease of new cases.

ABSTRACT Pseudomonas aeruginosa is one of the most common bacterium with a broad spectrum of human-associated infections. It is intrinsically resistant to many antimicrobial drugs, making carbapenems crucial in clinical management. The emergence and dissemination of carbapenemases among P. aeruginosa clinical isolates is a serious public health concern as it limits the options for the treatment of bacterial infections. Here, we described the molecular and epidemiological characteristics of 28 carbapenem-resistant P. aeruginosa strains isolated from patients hospitalized in an intensive care unit (ICU). The antimicrobial susceptibility of carbapenem-resistant P. aeruginosa strains was determined by broth microdilution. The presence of resistance genes was evaluated by PCR and DNA sequencing. Additionally, alterations in genes encoding P. aeruginosa outer membrane proteins were analyzed by PCR as well as SDS-PAGE. Clinical characteristics of the patients and the economic impact of hospitalization on the public health system were evaluated. PCR amplification showed that the blaKPC-2 and blaTEM genes were identified in three isolates (11%) and blaSHV gene in two isolates (7%). Outer membrane profiles obtained by SDS–PAGE indicated that the OprD porin was either absent or was produced at very low levels. A PCR assay using oprD-specific primers failed to show the presence of mutations in this gene. P. aeruginosa strains were isolated from 28 patients, among whom 43% (12/28) had sepsis, 31% (9/28) had respiratory failure, and 31% (9/28) had systemic arterial hypertension. A high mortality rate (39%) was observed in these patients, with an average duration of hospitalization of 34.6 days and a median cost of 3.275 dollars per patient. The production of carbapenemase was not the main mechanism of resistance in these strains. All carbapenem-resistant P. aeruginosa were isolated from patients hospitalized in the ICU. Besides the high mortality rate, many patients remained hospitalized for several days, resulting in a high cost of hospitalization for the public health system. Therefore, the evolution of this resistance and its dissemination should be actively monitored among critically ill patients to improve their health conditions.

ABSTRACT The present study proposes to characterize the parasites isolated during the initial phase of production in fish farms located in Mato Grosso do Sul in the central-western region of Brazil, using histopathology analysis and molecular techniques. A total of 340 hybrid surubim fish (Pseudoplatystoma reticulatum × P. corruscans) from four farms were examined during the co-feeding phase. Histopathology analysis showed that 10.9% (n = 37) of the fish were infected with parasites. Branchitis, lifting epithelium, hypertrophy of epithelial cells, lamellar fusion, aneurisms and infection in the bone tissue of the gill filament was observed. The parasite species was determined by amplification of the 18S rRNA gene followed by sequencing. The phylogenetic analysis of nucleotide sequences indicates a close relationship (99.6%) with Henneguya pseudoplatystoma reported to be infecting the hybrid Pseudoplatystoma. This study demonstrates the occurrence of H. pseudoplatystoma in hybrid surubim (P. reticulatum × P. corruscans) during the co-feeding phase in fish farms in Mato Grosso do Sul. Also, molecular techniques provide a faster and sensitive method to identify fish parasites, and may assist in the development of new management techniques aimed at improving the sanitary conditions contributing to the reduction of mortality rates in these animals.

Abstract INTRODUCTION: The increase in the prevalence of multidrug-resistant Acinetobacter baumannii infections in hospital settings has rapidly emerged worldwide as a serious health problem. METHODS: This review synthetizes the epidemiology of multidrug-resistant A. baumannii, highlighting resistance mechanisms. CONCLUSIONS: Understanding the genetic mechanisms of resistance as well as the associated risk factors is critical to develop and implement adequate measures to control and prevent acquisition of nosocomial infections, especially in an intensive care unit setting.

Abstract INTRODUCTION: Essential oils can serve as novel sources of antibiotics for multidrug-resistant bacteria. METHODS: The multidrug-resistance profile of a Klebsiella aerogenes strain was assessed by PCR and sequencing. The antibacterial activity of Cinnamomum cassia essential oil (CCeo) against K. aerogenes was assessed by broth microdilution and time-kill methods. RESULTS: K. aerogenes showed high antibiotic resistance. The genes bla KPC-2, ampC, bla CTX-M-15, bla OXA-1, and bla TEM were present. CCeo exhibited an inhibitory effect with a minimum inhibitory concentration of 17.57 μg/mL. CONCLUSIONS: The antibacterial activity of CCeo makes it a potential candidate for treating carbapenem- and polymyxin-resistant K. aerogenes strains.

ABSTRACT Syphilis is a public health problem, especially in pregnant women, due to the risk of transmission to the fetus and the involvement of the central nervous system, causing neurosyphilis. A case-control study was carried out to analyze the variables associated with neurosyphilis in Brazilian newborns of pregnant women with syphilis admitted for childbirth. Newborns were submitted to treponemal and non-treponemal tests, cerebrospinal fluid analysis, and long bone radiography. Newborns diagnosed with neurosyphilis and congenital syphilis were defined as cases and controls, respectively. The length of hospitalization and mean cost of neurosyphilis treatment were also evaluated. Twenty-one cases of newborns with neurosyphilis and 42 controls with congenital syphilis were included in the study. Out of 63 pregnant women with syphilis, 95.2% (60/63) received prenatal care, 74.6% (47/63) were diagnosed with syphilis during this period, 31.9% (15/47) underwent treponemic tests, 80.8% (38/47) were treated with penicillin and only 46.8% (22/47) of the partners received the treatment. Clinical complications such as low birth weight were observed in 12.7% (8/63) of the newborns. About 50.8% (32/63) of the newborns were hospitalized due to syphilis complications and each case of neurosyphilis spent at least US$ 881.48 on treatment and hospitalization. The results showed that the prenatal coverage is not sufficient to prevent neurosyphilis. The late diagnosis of syphilis in pregnant women and inadequate follow-up of sexual partners may favor the vertical transmission of T. pallidum in pregnant Brazilian women. Thus, improving the quality of health services is important for a more effective control of neurosyphilis.

Abstract INTRODUCTION: Syphilis infection remains an alarming public health problem worldwide. METHODS: This study analyzed syphilis cases listed in the Information System on Diseases of Compulsory Declaration (SINAN) of Mato Grosso do Sul state in Brazil between January 2013 and December 2014. RESULTS: Most of the evaluated syphilis cases would have been preventable through public education, particularly congenital syphilis in children of previously diagnosed mothers and infection by untreated sexual partners. CONCLUSIONS: The incidence rate of syphilis could be reduced by improving prevention through counselling on the risk of infection, improving access to condoms, and increasing the frequency of diagnostic tests.

Abstract INTRODUCTION: Plant products are sources for drug development against multidrug resistant bacteria. METHODS The antimicrobial activity of Origanum vulgare L. essential oil (OVeo) against carbapenem-resistant strains was assessed by disk-diffusion, microdilution (REMA-Resazurin Microtiter Assay), and time kill assays. RESULTS Carbapenemase production was confirmed for all strains. OVeo exhibited a minimum inhibitory concentration of 0.059% v/v for Klebsiella pneumoniae and Serratia marcescens, and of 0.015 % v/v for Acinetobacter baumannii. A decrease in cell count was observed after a 4 h treatment. CONCLUSIONS OVeo antimicrobial effect was rapid and consistent, making it a candidate for developing alternative therapeutic options against carbapenem-resistant strains.