Journal of Tropical Medicine最新文献

Toxoplasmosis, caused by the parasite Toxoplasma gondii, affects approximately 30% of the human population worldwide. Reactivation of latent infection in immunocompromised people leads to fatal disease. This study aimed to determine the seropositivity of toxoplasmosis by enzyme-linked immunosorbent assay (ELISA), confirmed by primary polymerase chain reaction (PCR) and nested PCR (nPCR), and validate ELISA against nPCR among a group of cancer patients. Of the 321 participants, six (1.9%) patients were positive for nPCR and both IgG and IgM ELISA tests while 36 (11.2%) and 131 (40.8%) showed evidence of possibly acute and past infection, respectively, and 15 (4.7%) were indeterminate. Among them, 19 (5.9%) nPCR positives would have been ignored as having evidence of past infection. Four (1.2%) patients would not have been treated at all if only ELISA had been performed as they had indeterminate ELISA results. This is the first study that used primary and nPCR with B1 gene amplification for confirmation of toxoplasmosis among cancer patients in Sri Lanka. These findings emphasize the need for confirmatory tests, such as nPCR, particularly in cancer patients who exhibit a weak antibody response. Implementing such tests can aid clinicians in effectively managing these patients, given the rising incidence and mortality rates of cancer in Sri Lanka.

Background: Tuberculosis increases human immunodeficiency virus replication and accelerates human immunodeficiency virus progression in both tuberculosis and human immunodeficiency virus coinfected patients. The objective of this study was to determine the incidence rate, survival rate, and predictors for virological failure among adult tuberculosis/human immunodeficiency virus coinfected clients. Methods: A retrospective cohort study was conducted at the University of Gondar Compressive Specialized Hospital from March 2017 to 2022. Secondary data sources were extracted based on inclusion criteria for adult tuberculosis/human immunodeficiency virus coinfected patients. The Cox proportional hazards model was used for adult tuberculosis/human immunodeficiency virus coinfected patients data. Result: The overall incidence rate of virological failure was 9.23 per 1000 person-months observations. Out of 148 coinfected patients, about 24.3% had virological failure. More than half of the patients, 52.7% and 54.1% in this study had a CD4 cell count ≥ 200/mm³ and a weight < 50 kg, respectively. Gender (hazard ratio = 1.3291, 95% CI: 1.1878-1.4873), bedridden functional status (hazard ratio = 4.7174; 95% CI: 1.2263-14.1470), WHO clinical Stage IV (hazard ratio = 1.1122, 95% CI: 1.2072-5.9693), patients with opportunistic infections (hazard ratio = 1.2849, 95% CI: 1.4289-3.8504), cotrimoxazole preventive therapy users (hazard ratio = 0.2039, 95% CI: 0.0496-0.8386), patients disclosure status (hazard ratio = 0.1609, 95% CI: 0.0279-0.9286), baseline viral load count < 1000 (hazard ratio = 0.0819, 95% CI: 0.3619-0.8447), and CD4 cell count ≥ 200 (hazard ratio = 0.2728, 95% CI: 0.0749-0.9924) were significant predictors at 5% level of confidence for time to virological failure. Conclusion: The incidence and survival rate of virological failure were high. The current study revealed that male coinfected patients, bedridden functional status, WHO clinical Stage IV, and opportunistic infections other than tuberculosis were associated with a higher time to virological failure while patients disclosed the disease to a family member, cotrimoxazole preventive therapy users, baseline viral load < 1000 copies/mL, and CD4 cell count ≥ 200/mm³ had significantly lower time to virological failure. Therefore, public health organizations should be given special attention based on these important predictors to improve their health and prolong the lives of coinfected patients.

Background: Toxoplasma gondii and rubella virus are significant health concerns among women. Therefore, it is crucial to determine the prevalence of their antibodies. Objective: This study aimed to explore the prevalence of rubella and toxoplasmosis immunoglobulin G (IgG) antibodies among females who attended different clinics in King Abdulaziz University Hospital, Jeddah, Saudi Arabia. Method: A retrospective observational study was conducted among nonpregnant women who attended various clinics at King Abdulaziz University Hospital in Jeddah, Saudi Arabia. The study included 540 female participants who visited various clinics, with a mean (standard deviation [SD]) age of 31.92 (6.175) years and a median (interquartile range [IQR]) of 32 (8). These women were tested for rubella and toxoplasmosis IgG and immunoglobulin M (IgM) from January 2021 to June 2022. ELISA test for detecting antitoxoplasmosis and antirubella IgG and IgM antibodies was conducted using kits manufactured by Abbott, located at Max-Planck-Ring 2, 65,205 Wiesbaden, Germany. Results: The majority of the participants were from Saudi Arabia (78.1%). Most females (73.3%) had positive results for rubella IgG, while only 5.6% tested positive for toxoplasmosis IgG. A significantly higher percentage of positive rubella-G antibodies was seen between those with positive toxoplasmosis IgG and those with negative toxoplasmosis IgG (93.3% vs. 76.4%, p=0.032). Non-Saudi females had a significantly higher rate of positive toxoplasmosis IgG than Saudi women (15.4% vs. 2.9%, p < 0.001). Conclusion: The study revealed a high prevalence of rubella antibodies and a low prevalence of toxoplasmosis antibodies among females living in Saudi Arabia, with a higher prevalence of toxoplasmosis antibodies seen among non-Saudi females. A significant association between the prevalence of rubella and toxoplasmosis antibodies was found. Therefore, raising awareness about the risks and prevention measures of toxoplasmosis is crucial, emphasizing hygiene practices.

Background: Staphylococcus epidermidis is an important cause of nosocomial infections in children. The study undertaken identified antibiotic resistance markers among biofilm-forming S. epidermidis. Methods: A total of 105 bacteremia-positive samples from hospitalized children were processed for identification of S. epidermidis using species-specific rdr gene. Phenotypic antibiotic resistance was checked through Kirby-Bauer disc diffusion method. 96-well microtiter plate assays and PCR were used for biofilm production and antibiotic-resistant genes, respectively. Results: Among 105 clinical isolates, rdr gene was detected in 34 (32.38%) isolates. The rdr detected isolates exhibited biofilm formation (n = 34; 100%). Multidrug-resistant (MDR) pattern was observed among S. epidermidis, while the frequency of MDR was higher in very strong biofilm-forming S. epidermidis (n = 18; 52.9%, p ≤ 0.002) as compared to weak biofilm-forming S. epidermidis (n = 6; 17.6%). All S. epidermidis strains were resistant to cefoxitin, penicillin, and augmentin (n = 34; 100%). High resistance was observed against erythromycin (n = 29; 85.29%) and ciprofloxacin (n = 25; 73.5%). S. epidermidis displayed complete susceptibility (n = 34; 100%) toward vancomycin, tetracycline, and linezolid. Among the S. epidermidis isolates, the methicillin resistance gene (mecA, n = 29; 85.2%, p ≤ 0.000), the erythromycin resistance gene (msrA, n = 19; 55.7%) and the beta-lactamase resistance gene (blaZ, n = 17; 50%) were detected. Detection of mecA (n = 17; 94.4%), msrA (n = 8; 44.4%) and blaZ (n = 11; 61.1%) significantly (p ≤ 0.0052) correlated with very strong biofilm-forming S. epidermidis. Conclusion: Biofilm formation is significantly associated with antibiotic resistance. The study's result will help to understand the molecular mechanism of antimicrobial resistance in biofilm-forming S. epidermidis among pediatric patients.

Background: Surgical site infections resulting from trauma orthopedic surgery increase morbidity and mortality rates and generate additional costs for the healthcare system. Preoperative and postoperative blood parameters have been described as risk predictors for surgical site infection in other surgical areas. The purpose of this study was to assess the role of preoperative and postoperative hematological parameters in predicting the risk of surgical site infections in trauma orthopedic surgery. Methods: Data on patients' demographics were collected from their medical records and the operation reports. Preoperative and postoperative blood samples were collected for a complete blood count assay. The blood cell parameters as predictors of surgical site infection after trauma orthopedic surgery were determined by the Mann-Whitney U test to assess the differences in the median between the dependent and independent variables. p value < 0.05 was considered statistically significant. Results: Out of the 210 patients who were followed postsurgery, 14 (6.7%) developed surgical site infection following trauma orthopedic surgery. The mean age of the study participants was 33.08 ± 19.23 (Mean ± SD), with a range of 86 to 0.67 years old. Low preoperative hemoglobin level was identified as a predictor of surgical site infection following trauma orthopedic surgery (p=0.019). None of the postoperative blood parameters measured was significantly associated with surgical site infections after trauma orthopedic surgery in Northern Ghana. Conclusion: In conclusion, our study demonstrates that preoperative hemoglobin level is a useful hematological parameter for predicting surgical site infection following trauma orthopedic surgery. These inexpensive and common hematological parameters could assist in guiding preventive efforts to reduce surgical site infections and improve outcomes for vulnerable patients undergoing trauma orthopedic surgery. Assessing preoperative hemoglobin levels is crucial in identifying patients at increased risk of developing surgical site infections. Preoperative optimization, including incorporating hemoglobin levels into predictive risk models can help to assess these at-risk persons better. Educate patients on the need to optimize their hemoglobin levels before surgery and discuss potential interventions, including iron supplementation or transfusion.

This study aimed to evaluate the effectiveness of the algorithm used in HIV diagnosis and to propose an effective new algorithm for rapid diagnosis. In accordance with CDC algorithm, our laboratory uses Architect HIVAg/Ab for screening and Geenius HIV1/2 and Artus HIVirus-1 QS-RGQ for confirmation. The Geenius test was used as a reflex and the HIV-1-RNA required clinician order. The HIVAg/Ab test was performed in 82,882 sera and found to be reactive in 262 (0.3%). HIV-antibody confirmatory testing was performed on 79% of samples with a reactive screening test, and the presence of HIV-1 antibodies was confirmed in 51% (105/206). Half of the samples with positive-screening but negative-antibody confirmatory results were tested for HIV1-RNA, and viremia was detected in 5, confirming acute HIV1 infection. HIV1-RNA was not ordered for 49 samples with positive-screening and negative antibody-confirmation tests, and 16 of these were considered false-reactive by the clinician. The Geenius assay result was indeterminate in 1.45% (3/206) of the samples. In the algorithm, the number of Geenius tests would have been reduced by 25% if HIV-1-RNA had been applied as a reflex test to HIV-Ag/Ab positive samples and Geenius testing had been performed on RNA negative samples. A retrospective analysis showed that the HIV diagnostic algorithm was not fully implemented. An important factor was that clinicians did not order HIV-1-RNA-PCR from ELISA reactive and Geenius test negative patients. Requesting HIV-1 RNA PCR as a reflex test is thought to prevent patient losses and shorten the turnaround time of the HIV diagnosis.

Background: The development of insecticide resistance in malaria vectors has necessitated a need to evaluate new insecticide molecules with different modes of action. In the present study, Fludora Fusion 562.5 WP-SB (clothianidin 50% + deltamethrin 6.25% AI/kg) was evaluated for its efficacy and residual action for the control of pyrethroid-resistant malaria vector, Anopheles culicifacies (Diptera: Culicidae), during May 2017 to February 2018 in Gujarat state, India. Methods: Fludora Fusion at the dose of 225 mg AI/m² and bendiocarb at a dose of 400 mg AI/m² as a positive control were sprayed in 5 villages each in districts of Kheda, Vadodara, and Panchmahal. The persistence of their efficacy on different local surfaces was determined against An. culicifacies. Entomological indices such as indoor resting density, human landing collections, pyrethrum spray collections, and exit trap collections were monitored to assess the impact of spraying. Results: The observed residual action of Fludora Fusion on mud and cement surfaces was for 6 months and bendiocarb for 3-4 months on both surfaces. Indoor resting densities and parous rate of An. culicifacies were significantly lower in houses sprayed with Fludora Fusion compared to bendiocarb-sprayed houses. Daily entomological inoculation rate (EIR) declined from 1.275 during prespray period to 0.5225 in the Fludora Fusion arm and 0.3802 in the Ficam arm in postspray period, indicating a reduction in the malaria transmission potential of An. culicifacies in both arms. Conclusion: Based on the residual action of the Fludora Fusion on most common sprayed surfaces and its effects on the elements of vectorial capacity, Fludora Fusion at 225 mg/m² dose was found effective for more than 6 months and could be a potential option for the control of resistant mosquito vectors.

Silymarin is a polyphenolic flavonoid extracted from milk thistle. It has potent immunomodulatory effects and can inhibit the replication of influenza A virus (IAV). The present study aimed to determine the inflammatory and anti-inflammatory cytokine secretion patterns in mice before and after silibinin treatment. For this, bronchoalveolar lavage (BAL) fluids were collected from the thoracic cavity 5 days after the intervention, and viral quantification was performed using TaqMan Real-time PCR. Enzyme-linked immunosorbent assay (ELISA) was used to evaluate IFN-γ and IL-10 levels in serum and BAL samples. Finally, pathological damage to lung tissue was assessed by pathologists. The results reveal that silibinin pretreatment exhibits a dose-dependent immunomodulatory effect on IFN-γ and IL-10 levels. After the virus challenge, silibinin reduced immune cell infiltration in mouse BAL fluid. These data similarly suggest a remarkable immunomodulatory effect of silibinin. Silibinin also decreased lung damage following the virus challenge in the post-treatment group, but its lung protective properties seem to be due to a different mechanism than when it was administered before infection. Finally, high doses of silibinin (post-treatment) significantly reduced viral load in BAL fluid compared to the virus challenge group. These results support the idea that therapies aimed at moderating immune and inflammatory responses are essential to decrease the mortality rate caused by IAV infection. Silibinin has strong immunomodulatory properties, can inhibit IAV infection, and reduces lung tissue damage in a dose-dependent manner.

Glycosaminoglycan (GAG) molecules on the surface of red blood cells play an important regulatory role in the invasion of merozoites of apicomplexan protozoa. Heparan sulfate, a type of GAG molecule, has been identified as an important receptor facilitating the invasion of red blood cells by these parasites. Proteins in the parasite that exhibit strong affinity for heparin may play a pivotal role in this invasion process. This study aims to use proteomics to identify Babesia microti proteins with high binding affinity to heparin. Bioinformatics was utilized to analyze the subcellular localization and biological functions of these proteins. Candidate genes encoding proteins with strong heparin affinity will be expressed in a prokaryotic system to produce recombinant proteins. The interaction between these recombinant proteins and heparin will be characterized through heparin-binding experiments and other methods. Initially, a mouse model of B. microti was established and high-density B. microti were obtained. Heparin affinity chromatography was then used to purify natural B. microti proteins that can bind to heparin, identifying 186 B. microti proteins via ESI-MS that specifically interact with heparin. Further studies were carried out to analyze those specific proteins with unique peptide segments of two or more, yielding 15 B. microti proteins, most of which are cell surface proteins and secretory proteins. Based on mass spectrometry identification and subsequent analyses, BMSA5-1-1, B. microti peptidyl-prolyl cis-trans isomerase (BmPPIase), and chaperonin were selected for further study due to their potential impact on the invasion of red blood cells by B. microti. These candidate proteins were expressed as recombinant proteins using a prokaryotic expression system. In vitro heparin-binding assays demonstrated that these recombinant proteins specifically bind to heparin. Notably, BmPPIase and chaperonin recombinant proteins exhibited activity in specific heparin binding. Molecular interaction studies further confirmed the strong interaction between BmPPIase and heparin. In conclusion, this study used proteomic methods to identify 186 specific B. microti proteins with specific binding affinity to heparin, providing in-depth analysis of 15 key proteins. The findings confirmed that BmPPIase and chaperonin specifically bind to heparin, with molecular interaction experiments substantiating the strong interaction between BmPPIase and heparin.

The loa22 protein is highly conserved among pathogenic Leptospira serovars and it is expressed during both acute and chronic infections. The aim of this study was to clone and sequence of the loa22 protein-encoding gene of Leptospira serovars. In this study, 23 pathogenic Leptospira serovars and two nonpathogenic Leptospira serovars were used. These serovars were obtained from the microbial culture collection of Leptospira Reference Laboratory, Department of Microbiology, Razi Vaccine and Serum Research Institute, Karaj, Iran. Three serovars, including L. Sejroe Hardjo-bovis, L. Grippotyphosa, L. Canicola, are used in the preparation of the trivalent vaccine. The loa22 gene was amplified by specific primers and the PCR products were then purified using kit and were cloned into a pTZ57R/T vector and transformed in competent E. coli DH5α cells. The cells were then plated onto LB agar containing ampicillin and recombinant colonies subjected to colony PCR to confirm the presence of the Leptospiral gene. Positive colonies plasmid vector was isolated from cells by High Pure Plasmid Isolation Kit. The loa22 gene was detected in all 23 pathogenic serovars, while this gene was not observed in nonpathogenic L. biflexa. It was determined that the similarity percentage of the sequenced pathogenic serovars is between 95.5% and 100%. The results concluded that the loa22 gene was highly conserved among various pathogenic Leptospira serovars and can be used to develop an effective recombinant vaccine.