Molecular identification of sulfadoxine-pyrimethamine resistance in malaria infected women who received intermittent preventive treatment in the Democratic Republic of Congo

Abstract Background Point mutations in Plasmodium falciparum dihydrofolate reductase (Pfdhfr) and dihydropteroate synthase (Pfdhps) genes which confer resistance to sulfadoxine-pyrimethamine (SP) occur at increasing rates. The present study aimed to identify Pfdhfr and Pfdhps mutations in P. falciparum isolates recovered from women who received two doses of SP during pregnancy in Bandundu, the Democratic Republic of Congo (DRC). Methods A total of 48 women with confirmed P. falciparum infection were enrolled in the study. Finger-prick blood samples that were collected on filter paper at the time of delivery were used for DNA isolation. Pfdhfr and Pfdhps genes were amplified by a nested PCR protocol. DNA sequencing was performed on both strands, and the point mutations were analysed. Results All of the 48 (100.0%) P. falciparum isolates carried at least one polymorphism in both genes. The wild-type haplotypes of Pfdhfr (CNCSI [C50, N51, C59, S108, I164]) and Pfdhps (SAKAA [S436, A437, K540, A581, A613]) were not observed in the study. In Pfdhfr, N51I (85.4%), C59R (60.4%), and S108N (100.0%) polymorphisms were detected. Triple mutation (CIRNI) (mutant amino acids are underlined) was the most prevalent (47.9%) Pfdhfr haplotype. In the study, all P. falciparum isolates (100.0%) harboured the A437G allele in Pfdhps gene. Also, K540E and A581G polymorphisms were observed in one (2.1%) isolate. Single mutant haplotype (SGKAA) was detected in 97.9% of the isolates. Mutant Pfdhfr and Pfdhps allele combinations revealed quintuple (CICNI-SGEGA; 2.1%), quadruple (CIRNI-SGKAA; 47.9%), triple (CICNI-SGKAA; 35.4%, CNRNI-SGKAA; 12.5%), and double (CNCNI-SGKAA; 2.1%) haplotypes. Conclusions In the study, the rate of SGEGA haplotype was low (2.1%). Although K540E and A581G alleles are more common in Eastern Africa, a distinct lineage of SGEGA is also present in the DRC, which is located in Central Africa. This haplotype is associated with decreased efficacy of SP in pregnant women and infants, therefore, it should be carefully considered in the DRC and SP resistance should be routinely monitored

Effect of Mixing Techniques on Bacterial Attachment and Disinfection Time of Polyether Impression Material

Objective: The aim of this study was 2-fold. The first aim was to evaluate the effects of mixing technique (hand-mixing or auto-mixing) on bacterial attachment to polyether impression materials. The second aim was to determine whether bacterial attachment to these materials was affected by length of exposure to disinfection solutions. Materials and Methods: Polyether impression material samples (n = 144) were prepared by hand-mixing or auto-mixing. Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa were used in testing. After incubation, the bacterial colonies were counted and then disinfectant solution was applied. The effect of disinfection solution was evaluated just after the polymerization of impression material and 30 min after polymerization. Differences in adherence of bacteria to the samples prepared by hand-mixing and to those prepared by auto-mixing were assessed by Kruskal-Wallis and Mann-Whitney U-tests. For evaluating the efficiency of the disinfectant, Kruskal-Wallis multiple comparisons test was used. Results: E. coli counts were higher in hand-mixed materials (P 2.394). Conclusion: The methods used for mixing polyether impression material did not affect bacterial attachment to impression surfaces. In contrast, the disinfection procedure greatly affects decontamination of the impression surface.PubMedScopu

Leishmaniasis in northern Cyprus: Human cases and their association with risk factors

Background & objectives: Cyprus is located in the eastern part of the Mediterranean Region where leishmaniasis is endemic. The primary objective of this study was to investigate human visceral leishmaniasis (VL) in the northern region of Cyprus where presence of canine leishmaniasis (CanL) and sandflies has been documented in earlier studies. The secondary objective was to assess the association of leishmaniasis with demographic and epidemiological variables. Methods: Intravenous blood samples were collected from 249 volunteers in Kyrenia district (located in the northern coastal region of Cyprus). Whole blood samples were tested for DNA of Leishmania spp by polymerase chain reaction (PCR), while serum samples were analyzed using direct agglutination test (DAT) and rK39 test. For evaluation of possible risk factors, a questionnaire was applied to the participants. Results: Only three (1.2%) of 249 participants were found seropositive by DAT (n = 2) or rK39 test (n = 1). The remaining samples were negative in serology, and no PCR positivity was detected in any of the 249 participants. Seven individuals, including the seropositive cases, had a history of cutaneous leishmaniasis (CL). Seropositivity and CL were not significantly related with gender (M/F: 40.2/59.8%), age [Mean: 42.85 +/- 17.45, Median: 40 (7-86)], occupation (Indoor/Outdoor: 84.7/12.9%), dog ownership (52.6%), and CanL history (5.3%). However, a statistical association was found between seropositivity and past CL infection. Also, a significant relation was observed between participants living in peripheral area (63.1%) and CL infection. Furthermore, leishmaniasis awareness (28.1%) among the study population was statistically correlated with past CL infection and dog ownership. Interpretation & conclusion: This study demonstrates the presence of leishmaniasis and highlight the need for implementation of efficient control measures on the northern coast of Cypru