40 research outputs found
First report of Cryptosporidium hominis in a freshwater sponge
Identification of Cryptosporidium oocyst is essential in ensuring water quality fit for human use, consumption, and recreation.This communication proposes the supplemental analysis of substrateassociated biofilms, in particular, freshwater sponges in improving case finding of waterborne-protozoan pathogens (WBPP) in environmental aquatic samples. In this study, a small portion of a mature freshwater sponge under the Genus Radiospongilla was subjected to microscopic and molecular analysis to identify the presence of Cryptosporidium. Microscopic screening with modified Kinyoun's staining (MK) and microscopic confirmation using direct antibody fluorescent testing (IFT) returned with Cryptosporidium spp. positive findings. Molecular investigation resulted in the confirmation of Cryptosporidium hominis upon sequencing of PCR products and phylogenetic analysis. This is the first report of a pathogenic protozoan, C. hominis isolated from a freshwater sponge. The results of this study provide evidence of the value of expanding water quality assessment strategies to the analysis of substrate-associated biofilms and sponges in improving case finding of WBPP in natural aquatic environments
Waterborne protozoan pathogens in environmental aquatic biofilms: implications for water quality assessment strategies
Biofilms containing pathogenic organisms from the water supply are a potential source of protozoan parasite outbreaks and a general public health concern. The aim of the present study was to demonstrate the simultaneous and multispatial occurrence of waterborne protozoan pathogens (WBPP) in substrate-associated biofilms (SAB) and compare it to surface water (SW) and sediments with bottom water (BW) counterparts using manual filtration and elution from low-volume samples. For scenario purposes, simulated environmental biofilm contamination was created from in-situ grown one-month-old SAB (OM-SAB) that were spiked with Cryptosporidium parvum oocysts. Samples were collected from the largest freshwater reservoirs in Luzon, Philippines and a University Lake in Thailand. A total of 69 samples (23 SAB, 23 SW, and 23 BW) were evaluated using traditional staining techniques for Cryptosporidium, and immunofluorescence staining for the simultaneous detection of Cryptosporidium and Giardia. In the present study, WBPP was found in 43% SAB, 39% SW, and 39% BW samples tested with SAB results reflecting SW and BW results. Further, the potential and advantages of using low-volume sampling for the detection of parasite (oo)cysts in aquatic matrices were also demonstrated. Scanning electron microscopy of OM-SAB revealed a naturally-associated testate amoeba shell, while Cryptosporidium oocysts spiked samples provided a visual profile of what can be expected from naturally contaminated biofilms. This study provides the first evidence for the simultaneous and multi-spatial occurrence of waterborne protozoan pathogens in low-volume environmental aquatic matrices and warrants SAB testing along with SW and BW matrices for improved water quality assessment strategies (iWQAS)
Trends in waterborne protozoan pathogens in East and Southeast Asia from 2010 to 2020: distribution, biodiversity, risk factor hierarchy, and methods
This scoping review is primarily concerned with defining the distribution, biodiversity, risk factors, and methods involved in waterborne protozoan pathogens in East and Southeast Asia covering the period of 2010 to 2020.
More importantly, this scoping review is concerned with drafting a risk factor hierarchy to organize the plethora of risk factors in a pragmatic approach that provides meaningful information for management and policy development from the level of domestic to international collaborative activities. Also, given the varying economic status of territories within East-Southeast Asia (Mostly developing) and the numerous methods for the detection of the target pathogens, this scoping review seeks to define the minimum requirements and considerations that will enable the detection of these pathogens even in resource-limited settings
The performance of tofu-whey as a liquid medium in the propagation of mycobacterium tuberculosis strain H37Rv
Objective: To investigate the performance of “tofu-whey liquid medium” for the propagation of Mycobacterium tuberculosis (MTB) strain H37Rv.
Method: Two hundred micro liters (200μl) of 1 McFarland standard (1mg/ml-bacillary suspension) were inoculated into different batches of tofu-whey liquid medium. Each series contained three trials of test (tofu-whey liquid medium) and control media (Middlebrook 7H9 medium). Turbidity was measured within three weeks of inoculation using a nephelometer. The combinations of various tofu-whey liquid culture media were as follows; T1 (tofu-whey+ADC+glycerol+Potassium sulfate+Magnesium citrate+Sodium glutamate); T2 (tofu-whey + ADC + glycerol + Potassium sulfate + Magnesium citrate); T3 (tofu-whey + ADC + glycerol + Potassium sulfate); T4 (tofu-whey + ADC + glycerol); T5 (tofu-whey + ADC); and T6 (tofu-whey only).
Results: In all test and control liquid culture media, the multiplication of M. tuberculosis was documented under light and fluorescence microscopy. Of various tofu-whey medium used, T1 demonstrated the most potential for MTB propagation. The increased turbidity reading represented by the value in “unit drop of % transmittance” was higher (25 scores) in the T1 tofu-whey medium, compared with the T6 tofu-whey medium (8 scores). The overall growth was significantly better in Middlebrook 7H9 culture media, although by the third day of incubation, the bacillary growth was superior in the T1 tofu-whey culture media. Sub-cultures in Lowenstein–Jensen (L–J) medium yielded between 87% (47 of 54) and 89% (48 of 54) recovery rate with between 7% and 13% contamination rate with coagulase-negative staphylococci.
Conclusion: Tofu-whey media can be used as an economical alternative to Middlebrook 7H9 in resource-limited settings
Association between ovalocytosis and Plasmodium infection: a systematic review and meta-analysis
Abstract Reports of an association between ovalocytosis and protection against Plasmodium infection are inconsistent. Therefore, we aimed to synthesise the overall evidence of the association between ovalocytosis and malaria infection using a meta-analysis approach. The systematic review protocol was registered with PROSPERO (CRD42023393778). A systematic literature search of the MEDLINE, Embase, Scopus, PubMed, Ovid, and ProQuest databases, from inception to 30 December 2022, was performed to retrieve studies documenting the association between ovalocytosis and Plasmodium infection. The quality of the included studies was assessed using the Newcastle–Ottawa Scale. Data synthesis included a narrative synthesis and a meta-analysis to calculate the pooled effect estimate (log odds ratios [ORs]) and 95% confidence intervals (CIs) using the random-effects model. Our database search retrieved 905 articles, 16 of which were included for data synthesis. Qualitative synthesis revealed that over half of the studies showed no association between ovalocytosis and malaria infections or severity. Furthermore, our meta-analysis demonstrated no association between ovalocytosis and Plasmodium infection (P = 0.81, log OR = 0.06, 95% CI − 0.44 to 0.19, I2: 86.20%; 11 studies). In conclusion, the meta-analysis results demonstrated no association between ovalocytosis and Plasmodium infection. Hence, the role of ovalocytosis in relation to protection against Plasmodium infection or disease severity should be further investigated in larger prospective studies
Differences in catalase levels between malaria-infected individuals and uninfected controls: a systematic review and meta-analysis
Abstract Inconsistent catalase (CAT) research necessitates a comprehensive review of CAT levels among patients with malaria to achieve better therapeutic strategies. This study aimed to systematically review and meta-analyze available literature on CAT levels in nonpregnant and pregnant individuals with malaria compared with those in uninfected controls, with the goal of providing a robust evidence base for future research and potential interventions. Following PRISMA guidelines, a systematic literature search across six databases was conducted to examine CAT levels in patients with malaria. Data was extracted independently by two reviewers, and study quality was assessed using the Joanna Briggs Institute (JBI) critical appraisal checklist. The standardized mean difference of CAT levels was calculated with heterogeneity assessment. Subgroup and sensitivity analyses were conducted to explore heterogeneity and assess the robustness of the findings. Publication bias was visually and statistically assessed and corrected, if necessary. Statistical analyses were performed using Stata software, with a significance level set at P < 0.05. Nineteen studies were included in the review. These studies, published from before 2000 to 2023, primarily from Africa and Asia, focused on different Plasmodium species and age groups. Results of qualitative synthesis among nonpregnant individuals consistently showed lower CAT levels in malaria-infected individuals, although some studies reported higher levels. No significant differences in CAT levels were found between malaria-infected and uninfected individuals, as demonstrated by a meta-analysis overall (P = 0.05, Hedges’ g: − 0.78, 95% confidence interval (CI): (− 1.56)–0.01, I2: 98.47, 15 studies), but subgroup analyses showed significant differences in CAT levels in studies conducted in Africa (P = 0.02, Hedges’ g: − 0.57, 95% CI: − 1.02–(0.11), I2: 91.81, 7 studies), and in studies that specifically focused on children (P = 0.03, Hedges’ g: − 0.57, 95% CI: − 1.07–(− 0.07), I2: 87.52, 4 studies). Pregnant women showed variations in CAT levels across trimesters. This study provides valuable insights into the association between malaria infection and CAT enzyme levels, particularly in nonpregnant individuals. Furthermore, well-designed studies are essential to decoding the intricacies of this relationship, which could have significant implications for understanding disease processes and improving patient care
Evidence of malarial chemoprophylaxis among travellers who died from malaria: a systematic review and meta-analysis
Abstract Background Chemoprophylaxis is a prevention method for malaria during travel in malaria-endemic countries. This study aimed to collate and synthesize the evidence of malarial chemoprophylaxis among malaria death cases. Methods Studies documenting malarial chemoprophylaxis related to malaria deaths were searched in PubMed, Scopus, MEDLINE, Embase, and CENTRAL until 3 July 2022. The pooled proportion of malarial chemoprophylaxis among death cases was synthesized using logit transformation and back transformation to a proportion performed using generalized linear mixed models. The pooled log odds ratio (log-OR) with a 95% confidence interval (CI) of malarial chemoprophylaxis in death cases compared to survivors were synthesized. Results Fifty-eight studies were included in the systematic review and the meta-analysis. Of 602 pooled malaria death cases, the number of patients who took chemoprophylaxis was 187 (30%) (95% CI 22–40, P < 0.01, 58 studies), and those who took adequate chemoprophylaxis were 24 (5%) (95% CI 2–13, P < 0.01, 42 studies). A comparable log-OR of underwent chemoprophylaxis was observed between malaria death cases and survivors (P = 0.94, pooled log-OR: − 0.02, 95% CI − 0.46–0.42, I2: 0%, 17 studies). Similarly, a comparable log-OR of adequate chemoprophylaxis was identified between malaria death cases and survivors (P = 0.15, pooled log-OR: 0.83, 95% CI − 0.30–1.97, I2: 47.08%, 11 studies). Conclusions Among the studies where malarial chemoprophylaxis was reported, approximately 30% of malaria death cases had taken such prophylaxis. Notably, only 5% of these cases adhered fully or adequately to the recommended chemoprophylactic regimen. However, the analysis did not reveal a significant difference in the odds of malarial chemoprophylaxis between malaria death cases and survivors
Detection of potentially pathogenic free-living amoebae from the Caspian Sea and hospital ward dust of teaching hospitals in Guilan, Iran
Free-living amoebae (FLA) thrive in diverse environmental conditions. The present study aimed to define the FLA distribution from the Caspian Sea as well as from hospital ward dust from Guilan, Iran. Seawater (20) and hospital ward dust samples (100) were collected from May to June 2018. Seawater samples were vacuum filtered through a 0.45 mu m pore-size membrane. Dust was collected using sterile gauze, washed with sterile distilled water, with washings collected thereafter. Washings were similarly filtered as seawater samples. FLA from the filtered material was cultivated in non-nutrient agar. Molecular analysis was performed by PCR and sequencing using specific primers for Acanthamoeba, Naegleria, and Vermamoeba/Hartmanella. Culture and PCR returned 50 and 65% positivity, respectively, for seawater samples where sequencing revealed Acanthamoeba T2, T5 and T6 genotypes and A. palestinensis and A. lenticulata, as well as N. dobsoni and N. clarki. In addition, 30% amoebic growth and 16% PCR detection were observed from hospital ward dust samples where sequencing revealed Acanthamoeba T2, T4 and T11 genotypes and A. castellanii, A. palestinensis and A. stevensoni as well as N. clarki. For both seawater and dust samples, Acanthamoeba was the dominant isolate. The detection of potentially pathogenic FLA from seawater may pose a threat to the public, while the presence of the same in dust spells threats to both hospital staff and patients, in particular, immunocompromised individuals. Public education, awareness, improved sanitation and hygiene, and the crafting of diagnostic strategies for the early detection of FLA in humans are necessary for the mitigation and management of potential human infection cases
Reduction in total leukocytes in malaria patients compared to febrile controls: A systematic review and meta-analysis.
BackgroundLeukocyte alterations are a common hematological alteration among malaria patients.ObjectivesThis systematic review and meta-analysis aimed to provide data and evidence comparing alterations in total leukocyte counts in malaria patients compared to febrile/healthy subjects at baseline before treatment. A systematic review was conducted by following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement for reporting systematic reviews and meta-analyses.Data sourcesWeb of Science (ISI), Scopus, and Medline.Study eligibility criteria, participants, and interventionsAll published articles reporting a total leukocyte count of patients infected with malaria, non-malaria (febrile or healthy group) at baseline before treatment before August 27, 2019, were retrieved, and data were extracted by two main reviewers independently.Study appraisal and synthesis methodsWe used a forest plot, heterogeneity test (Cochran's Q), and the degree of heterogeneity (I2) to test whether the included studies were heterogeneous. The quality of the included studies was determined by a quality assessment guide based on the quality assessment tool developed by the Newcastle-Ottawa Scale (NOS). Cochran's Q (Chi-square) and Moran's I2 were used to evaluate heterogeneity. Meta-regression using STATA software was conducted to find the source of heterogeneity. A funnel plot with Egger's test was used to examine the significance of publication bias among the included studies. The mean differences were estimated using a random-effects model.ResultsOut of the 2,261 articles screened, 29 articles were included in this systematic review and meta-analysis. The heterogeneity test indicated that there was heterogeneity among the included studies with no publication bias. The meta-analysis demonstrated that the total leukocyte count was significantly lower in patients with malaria (n = 4,619) than in those without malaria (n = 10,056) (Z = 4.0, P-value 0.05).LimitationsAs the specific diagnoses in the febrile groups were not reported in the included studies so that the results of the present study need to be carefully interpreted.Conclusions and implications of key findingsThis systematic review demonstrated that the total leukocyte count was affected by malarial infection at baseline despite the heterogeneity of the included studies. Future work must aim to understand the treatment-related total leukocyte reduction during follow-up or post-treatment outcomes in malaria-endemic settings