Tropical Parasitology最新文献

Background: Periodontal disease is often caused by bacterial plaque. However, there are indications that some infective agents, including parasites, may play important roles in the pathogenesis of the disease.

Aim: This study aimed at assessing the prevalence of gingivitis and periodontitis, as well as the prevalence of Entamoeba gingivalis and Trichomonas tenax, in the oral biofilm of individuals with periodontal diseases using polymerase chain reaction.

Materials and methods: One hundred and six respondents with periodontal disease participated in the study. All study participants had a full-mouth examination, and dental plaque samples were collected with a sterile curette. Samples were transported to the laboratory in a cold chain and stored frozen till analyzed. DNA was extracted from the samples and amplified using EGO and ENTAM primers for Entamoeba and TGBK primers for T. tenax.

Results: The mean age of respondents was 45 ± 16.3 years, with none using tobacco. The prevalence of gingivitis and periodontitis obtained from this study was 84.9% and 15.1%. The prevalence obtained for Entamoeba and T. tenax was 0.9% each; however, no participant had both parasites. The positive samples were from male participants with moderate gingivitis.

Conclusion: Gingivitis was more prevalent than periodontitis, though with a high preponderance in females. E. gingivalis and T. tenax may not be of etiologic importance in periodontal disease as they occurred sparsely in the studied population.

Immunocompromised patients with human immunodeficiency virus (HIV) infection are prone to multiple infections, of which parasitic infections are an important cause. Parasitic protozoal infections - both by common and rare protozoa are documented in such patients. Here, we report a rare and interesting case of five protozoal infections affecting a single HIV-infected person at the same time of initial presentation. A 64-years-male came to us with complaints of chronic diarrhea for 6 months. He was investigated and found to be positive for HIV I. His stool examination revealed cysts of Entameba histolytica and Giardia lamblia and oocysts of Cryptosporidium species and Cystoisospora species. His toxoplasma IgG was also positive in high titer. The patient was medically diagnosed and was treated with medications as clinically prescribed - antiretroviral therapy was initiated and he was discharged in due course. A total of five protozoal infections were documented affecting a single person - newly diagnosed immunocompromised male, which by sheer qualitative count of patient case histories, indeed is a rare case reported in the medical literature.

Acute appendicitis secondary to amoebic infestation is a rare possibility, especially in endemic areas. If left untreated, significant postoperative morbidity and mortality can result from the spread of amoebic trophozoites and subsequent tissue reaction. Histopathological examination of the resected appendix with demonstration of invasion by the parasite is mandatory for establishing a diagnosis. Careful examination of the specimen is thus of paramount importance.

Background: The complex life cycle of geohelminth parasites make it difficult to manage repeated infections that occur in endemic areas, that requires the development of new therapeutic strategies. Human hookworm Ancylostoma sp. and Necator sp. are a serious problem in many areas of the world where the old age anti-helminthics are ineffective. To address this, we have tried a non-traditional therapeutic approach for a sustainable solution to manage parasite infections.

Aims and objectives: In this study, we attempted to develop a new type of therapy using value-added probiotics-producing antiparasitic RNA interference (RNAi) molecules against a vital hookworm (Ancylostoma sp.) enzyme, astacin-like metalloprotease Ac-MTP-1. A new gut delivery RNAi vector was designed to produce double-stranded RNA (dsRNA) against the target to be delivered by feeding with a probiotic Lactococcus lactis that when administered in endemic areas can potentially be used to control the spread of infection by interrupting the life cycle of hookworm.

Results: The engineered probiotics colonizing the gut, when consumed by the parasite released the dsRNA that which knocked down the target by RNAi interfering with their moulting and tissue migration. The initial penetration of the larvae into the gut lining was reduced by 70%, followed by a reduction of up to 50% in migration to the critical organs. The damage caused to the liver (30%-40%) and the kidneys (50%-60%) by the hookworm in mouse models as quantitated by enzymes released in the blood was totally reversed when the worms were pre fed with the engineered L. lactis before the parasite challenge.

Conclusions: We believe that this is the first demonstrated knockdown of a target gene in hookworms using probiotics genetically engineered to stimulate RNAi (RNAi food), administered through the oral route. This novel method of parasite control when extended to other hookworms, A. duodenalis and A. ceylanicum can augment the efficacy of the existing anthelminthics if combined with them.

Background: Ascariasis is a common disease in humans and pigs. In previous reports, it has been known that ascariasis in humans is not only caused by Ascaris lumbricoides but also by Ascaris suum which is known to originate from pigs.

Aims and objectives: This research aims to identify the species of Ascaris that infect traditional pig farmers in Bali, Indonesia.

Materials and methods: To achieve this, an observational study was conducted, in which 239 feces samples were collected from traditional pig farmers. The collected samples were then divided into two parts, with one part stored in a pot containing 10% formalin for microscopic testing, and the other part stored in 70% ethanol for molecular testing. In cases where Ascaris infection was observed during the microscopic examination, a further test was conducted using the polymerase chain reaction (PCR) method for molecular examination. The DNA derived from the PCR was then subjected to DNA sequencing.

Results: The result was compared to A. suum gene data previously published in the Gene Bank. The results of the microscopic examination showed that 22 farmers were infected with Ascaris. However, PCR testing and DNA sequencing indicated that three infections were caused by A. suum.

Conclusion: Therefore, it can be concluded that A. suum is a zoonosis in Bali. Thus, efforts to control ascariasis must pay attention to the presence of pigs around it. Handling of ascariasis is not only carried out in humans but also in pigs and the environment.

Human dirofilariasis is a rare infection caused by filarial worms of genus Dirofilaria. Humans may be infected as aberrant (accidental) hosts, mainly by Dirofilaria repens and Dirofilaria immitis. Most of the cases reported in India are of ocular dirofilariasis, with a few reports on subcutaneous dirofilariasis. We hereby report one such case of human subcutaneous dirofilariasis affecting the neck region of a 63-year male patient from Assam. This case indicates that this infection is a potentially emerging zoonosis in Assam and there is scope of finding more such cases with surveillance.

Nonhuman primate (NHP) malaria poses a major threat to the malaria control programs. The last two decades have witnessed a paradigm shift in our understanding of the malaria caused by species other than the traditionally known human Plasmodium species - Plasmodium falciparum, Plasmodium vivax, Plasmodium malariae, and Plasmodium ovale. The emergence of the malaria parasite of long-tailed macaque monkeys, Plasmodium knowlesi, as the fifth malaria species of humans has made the scientific community consider the risk of other zoonotic malaria, such as Plasmodium cynomolgi, Plasmodium simium, Plasmodium inui, and others, to humans. The development of knowledge about P. knowlesi as a pathogen which was earlier only known to experimentally cause malaria in humans and rarely cause natural infection, toward its acknowledgment as a significant cause of human malaria and a threat of malaria control programs has been made possible by the use of advanced molecular techniques such as polymerase chain reaction and gene sequencing. This review explores the various aspects of NHP malaria, and the association of various factors with their emergence and potential to cause human malaria which are important to understand to be able to control these emerging infections.