Molecular characterization of Treponema pallidum isolates from Brazil.

Syphilis remains a public health concern in Brazil, and the data on the characterization and resistance of Treponema pallidum in Brazil is limited. The present study aimed to detect Treponema DNA in the lesions and blood samples obtained from individuals diagnosed with syphilis. The Brazilian isolates were submitted to the Enhanced Centers for Disease Control and Prevention (ECDC) scheme and also analyzed for resistance gene. Treponemal DNA from 18 lesions and 18 blood specimens were submitted for amplification using Polymerase Chain Reaction (PCR) and Polymerase Chain Reaction in Real Time (RT-PCR). Eight samples from lesions and eight from blood were positive in the RT-PCR analysis. Eight lesions and three blood samples were positive using PCR. Two samples exhibited azithromycin resistance. The Brazilian isolate types 14d/g, 14 d/c, 15d/c, and 15d/e were identified using the ECDC scheme. The three subtypes 14d/c, 15d/c, and 15d/e have been identified in Brazil for the first time.

Seroprevalence of Treponema pallidum infection among high-risk populations from Brazil.

Syphilis is a significant public health concern worldwide. According to the 2020 estimates, nearly 7.1 million new cases of syphilis have been reported globally, with over 30 % of these cases reported from American nations, particularly Brazil. Concerns have been raised regarding the susceptibility of specific groups to syphilis due to challenges and vulnerabilities that place these groups at a higher risk of infections or complications in the treatment outcomes. The present study aimed to compare the seroprevalence and the factors associated with syphilis among such high-risk groups. The study was designed as a cross-sectional one and was conducted with pregnant women, people living with HIV (PLHIV), people living with tuberculosis (PLTB), indigenous and healthy populations in Mato Grosso do Sul, Brazil. The study was conducted between June 2019 and August 2022, during which the included patients were subjected to treponemal and non-treponemal serological assays. The study also included a survey conducted through a self-reported questionnaire to collect information regarding the participants' demographics and sexual behaviors. A total of 550 samples were collected, with 110 participants in each of the five groups. The results of the study revealed that the seroprevalence of Treponema pallidum infection in pregnant women, PLHIV, PLTB, indigenous and healthy populations of the study region was 10 % (n = 11/110), 41.81 % (n = 46/110), 17.27 % (n = 19/110), 5.45 % (n = 6/110), and 8.18 % (n = 9/110), respectively. Homosexual orientation (p = 0.04) and a history of sexually transmitted infection (STI) (p = 0.01) were associated with the seroprevalence of T. pallidum infection in PLHIV. However, no such associations were noted in the remaining four groups. The seroprevalence of T. pallidum infection was observed to vary significantly among the different high-risk groups, which highlighted the persistent concern of syphilis, particularly among vulnerable populations. These findings underscore the significance of focused interventions and public health strategies customized to the specific requirements of each of the groups evaluated in the present study to decrease the number of cases of syphilis and thereby prevent future complications in patients with other serious infections.

Detection of Treponema pallidum in whole blood samples of patients with syphilis by the polymerase chain reaction.

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.

Detection of Treponema pallidum in whole blood samples of patients with syphilis by the polymerase chain reaction

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.

Epidemiological study in Brazilian women highlights that syphilis remains a public health problem.

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.

Synergistic effects of Cinnamomum cassia L. essential oil in combination with polymyxin B against carbapenemase-producing Klebsiella pneumoniae and Serratia marcescens.

Multidrug resistance prompts the search for new sources of antibiotics with new targets at bacteria cell. To investigate the antibacterial activity of Cinnamomum cassia L. essential oil (CCeo) alone and in combination with antibiotics against carbapenemase-producing Klebsiella pneumoniae and Serratia marcescens. The antimicrobial susceptibility of the strains was determined by Vitek® 2 and confirmed by MALDI-TOF/TOF. The antibacterial activity of CCeo and its synergism with antibiotics was determined using agar disk diffusion, broth microdilution, time-kill, and checkboard methods. The integrity of the bacterial cell membrane in S. marcescens was monitored by protein leakage assay. CCeo exhibited inhibitory effects with MIC = 281.25 µg.mL-1. The association between CCeo and polymyxin B showed a decrease in terms of viable cell counts on survival curves over time after a 4 hour-treatment with a FIC index value of 0.006. Protein leakage was observed with increasing concentrations for CCeo and CCeo + polymyxin B treatments. CCeo showed antibacterial activity against the studied strains. When associated with polymyxin B, a synergistic effect was able to inhibit bacterial growth rapidly and consistently, making it a potential candidate for the development of an alternative treatment and drug delivery system for carbapenemase-producing strains.

High Prevalence of Syphilis and Inadequate Prenatal Care in Brazilian Pregnant Women: A Cross-Sectional Study.

In Brazil, the reported number of syphilis cases among pregnant women has markedly increased. We conducted a cross-sectional study to determine the prevalence of Treponema pallidum infection and associated factors in pregnant women in Dourados, Mato Grosso do Sul, Brazil. Participants voluntarily completed a risk-factor questionnaire and provided blood specimens for unlinked anonymous testing for the presence of antibodies against T. pallidum, the causative agent of syphilis. Data of newborns were obtained from medical records. We performed univariate and multivariate regression analyses to assess associations with syphilis. The seroprevalence of syphilis in pregnant women was 4.4% (n = 29/661). Twenty-five newborns were seropositive for T. pallidum, and complications due to syphilis were observed in 28% (n = 7/25). Although 96.5% (n = 28/29) of women with syphilis received antenatal care, Venereal Disease Research Laboratory tests were performed in the first trimester for 47.6% (n = 10/21) of women. Women who received treatment in the third trimester (28.6%; n = 6/21) were considered successfully treated at the time of delivery. The use of illicit drugs during pregnancy (odds ratio [OR]: 13.3, 95% CI: 1.9-91.2) and a history of abortion (OR: 3.7, 95% CI: 1.7-8) were associated with syphilis. Our findings highlight that the poor quality of antenatal care services contributes to the high prevalence of syphilis. In addition, there are social and behavioral risk factors associated with syphilis in pregnant women. Future studies are needed to determine limitations of clinical management and control services available to pregnant women with syphilis.