ASSESSMENT OF THE OXIDATIVE AND NITROSATIVE STRESS IN THE SERUM OF SAUDI PATIENTS WITH CUTANEOUS LEISHMANIASIS BEFORE AND AFTER TREATMENT.

Macrophages, within which Leishmania species replicate, generate large amounts of reactive oxygen species (ROS) and reactive nitrogen species (RNS) to kill these parasites. The present study assessed the oxidative and nitrosative stress, and specific immune enzymes in the serum of patients with cutaneous leishmaniasis (Cl) before and after treatment and in the control individuals. Serum activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), L-arginase, myeloperoxidase (MPO), and adenosine deaminase (ADA) and the levels of reduced glutathione, malondialdehyde (MDA), and nitric oxide (NO) were studied. The activities of L-arginase, MPO, and ADA and the levels of MDA and NO were significantly elevated (P < 0.001), while the activities of SOD, CAT, and GSH-Px, and the levels of reduced glutathione (GSH) were significantly (P < 0.001) reduced in untreated patients as compared with values of patients after treatment and of control individuals. The treatment, which included intramuscular injection of sodium stibogluconate and meglumine antimoniate, ameliorated these factors in comparison to the untreated group. These results suggest that oxidative and nitrosative stress may play an important role in the pathogenesis of untreated cutaneous leishmaniasis. Furthermore, the reduction in oxidative and nitrosative stress in the treated Cl patients may be due to the drug decreasing energy production by the parasite, which eventually leads to its death.

Molecular Detection of Leishmania spp. in Skin and Blood of Stray Dogs from Endemic Areas of Cutaneous Leishmaniasis in Saudi Arabia.

BACKGROUND: Dogs can act as reservoirs of canine leishmaniasis, caused by Leishmania species. The aims of this study were to determine the prevalence of canine leishmaniasis using a PCR technique among stray dogs living in three provinces of Saudi Arabia, Riyadh, Al-Ahsa Oasis and Al-Qaseem, where the disease is endemic; and to identify and document different Leishmania to species levels. METHODS: This cross-sectional investigation was conducted, from Mar 2016 to Apr 2018, in three parts of Saudi Arabia: Central province (Riyadh), Eastern province (Al-Ahsa Oasis) and Al-Qaseem province. Blood samples were collected from 526 dogs; 40 presented cutaneous nodules so were suspected clinically of cutaneous leishmaniasis. Biopsy tissue collections and parasite cultures were performed. A generic kDNA was performed using different primers for Leishmania differentiation. RESULTS: All blood samples were negative for Leishmania infantum infection by molecular analysis, though forty dogs had thick cutaneous lesions in different parts of their body. Four dogs' skin lesions were associated with dermatitis, splenomegaly and lymphadenomegaly. Parasite culture was used to diagnose cutaneous leishmaniasis, identifying 31/40 (77.5%) positive samples. Overall, of 526 samples, the prevalence of L. major and L. tropica was found to be 4% and 1.9%, respectively. Gender and age had a significant effect on Leishmania prevalence: (P=0.0212 and 0.0357), respectively. CONCLUSION: This was the first molecular study of dog leishmaniasis from Saudi Arabia of dogs confirmed to have cutaneous leishmaniasis. Further epidemiological and molecular investigations of domestic and wild canine infections with L. major, L. tropica and L. infantum in endemic and nonendemic areas of Saudi Arabia are required, for leishmaniasis control.

Species Diversity and Seasonal Distribution of Hard Ticks (Acari: Ixodidae) Infesting Mammalian Hosts in Various Districts of Riyadh Province, Saudi Arabia.

Hard ticks are among the most important blood sucking arthropods that transmit pathogens to humans and animals. This study was designed to determine prevalence, mapping, geographical distribution, and seasonal activity of hard tick species infesting the most common domestic and wild mammals in various districts of Riyadh Province, Saudi Arabia, during the period January to December 2017. In total, 10,832 adult hard ticks were collected from the bodies of 8,435 animals belonging to 18 different mammalian species. The ticks were preserved in 70% alcohol and microscopy was used to identify species. Two genera, Hyalomma and Rhipicephalus, were identified, comprising 10 species of hard ticks, with Hyalomma comprising 68.3% and Rhipicephalus comprising 31.7% of species. The most common species on domestic mammalian hosts was Hyalomma dromedarii (Koch 1844) (39.9%) followed by Rhipicephalus turanicus (Pomerantsev, Matikashvili & Lotosky 1936) (34.9%), whereas on wild mammalian hosts Rhipicephalus sanguineus (Latreille 1806) was by far the most prevalent species (83.0%). However, ticks were most abundant during May through July (36.0%) in the studied areas, and tick intensity and abundance differed among seasons. Our results provide information for human and animal health service managers, as well as governmental authorities, to gain a better understanding of hard ticks infesting mammalian hosts in Riyadh Province, Saudi Arabia, which can help improve prevention and control of tick-borne diseases, especially during outbreaks.

A field study on the anthelmintic resistance of Parascaris spp. in Arab foals in the Riyadh region, Saudi Arabia.

BACKGROUND: In the last decade, Parascaris spp. resistance to anthelmintics has been recorded in many countries. In Saudi Arabia, there are limited data available on Parascaris spp. resistance to anthelmintics. OBJECTIVE: To determine the current status of ivermectin, abamectin and praziquantel combined, and fenbendazole resistance to Parascaris spp. in horses in Saudi Arabia. METHODS: Three hundred and forty-one foals from eleven different farms were examined by faecal egg count (FEC). The foals were all Arab horses aged 17.2 ± 4.5 (SD) months. Ivermectin (n = 46 foals), abamectin and praziquantel combined (n = 46), and fenbendazole (n = 46) were administered on day 0 and faeces were collected on day 14. The study comprised 41 untreated foals as controls. Animals that have FEC of ≥100 eggs per gram (EPG) were used to measure anthelmintic efficacy. Parascaris spp. populations were considered susceptible when faecal egg count reduction (FECR) was ≥95% associated with a lower 95% confidence limit (LCL) >90%, suspected resistant when FECR ≤90% or LCL <90% and resistant when FECR <90% and LCL <90%. RESULTS: Prevalence of Parascaris spp. infection was 53% (179/341 horses). Anthelmintic resistance to Parascaris spp. were highest following fenbendazole (55% of farms and 65% of foals) and to a lower extent following ivermectin or the combination of abamectin and praziquantel which comprised 27% of farms (and 46% of foals) and 18% of farms (and 10% of foals), respectively. CONCLUSION: These data indicate that anthelmintics-resistant Parascaris spp. populations are present on horse farms in Saudi Arabia.

Genotypes of Giardia intestinalis clinical isolates of gastrointestinal symptomatic and asymptomatic Saudi children.

Giardiasis is the most worldwide parasitic disease with the major clinical impact on infant and children. Two genotypes were reported commonly among humans (assemblage A and B). In this study, genotypes of Giardia intestinalis clinical isolates obtaining from 24 gastrointestinal symptomatic Saudi primary school children and 16 asymptomatic ones were explored by real-time polymerase chain reaction using the high resolution melting curve analysis targeting intergenic spacer (IGS) region rDNA of G. intestinalis. Children having acute, intermittent, and chronic diarrhea were 14, 5, and 5, respectively. Among all the giardiasis subjects, assemblage B was 37.5% followed by both of assemblages AI and AII with 30% and 27.5%, respectively. Mixed infection with the three previous assemblages was present in 5% of cases. Among symptomatic children, the prevalence of assemblage B was 62.5% then followed by assemblage AI (16.7%) and assemblage AII with 12.5%. All of the children who harbored G. intestinalis assemblages B were symptomatic, while asymptomatic ones had only assemblage AI and AII with 50% each. The difference was statistically highly significant. In symptomatic patients having acute diarrhea, assemblage B was present in 71.5%, while assemblage AI and AII were equal with 7.1%. All of the patients (14.3%) with mixed infection had acute diarrhea. In intermittent diarrhea, assemblage AI and B were equally distributed with 40% each. In chronic diarrhea, assemblage AI and AII were equal with 20% each, while assemblage B was found in 60%. The difference was statistically not significant. In conclusion, assemblage B is the commonest, while assemblage A is a predominant in symptomatic and asymptomatic giardiasis Saudi children, respectively. So human transmission is the common risk factor among symptomatic, while zoonotic transmission is a common risk factor in asymptomatic ones. On the other hand, a strong correlation between assemblage B and symptoms and no relation between genotypes and types of diarrhea are found. Also, PCR with HRM in one-step closed-tube methods is able to genotype G. intestinalis IGS rDNA without using the sequencing methods or the electrophoresis.

Efficacy of two rodenticides against Leishmania reservoir host rat (Psammomys obesus) in the rural area of Al-Ahsa Oasis, Saudi Arabia.

Zoonotic cutaneous leishmaniasis (ZCL) is a serious and increasing public health problem in many parts of Saudi Arabia. Rodent control operations are effective in destroying rodents and reducing the incidence of disease. This study tested the efficacy of zinc phosphide and fenacoum against the reservoir host Psammomys obesus rat. The results showed that both the rodenticides were significantly (P < 0.01) effective in reducing the number of active holes during one year of application.

Description of Nematotaenia dispar from gray monitor (Varanus griseus) a new record in Saudi Arabia.

Due to the increasing information on the reptile fauna in Saudi Arabia and the importance of this group of vertebrate animals, it is of great interest to study the parasites that can infect them. Out of total ten gray monitor Varanus griseus of both sex, only three were found to be infected (representing an infection rate of 30%) with parasitic worms. The parasitic burden index was 20. As regards to sex, 60.7% of the infected Varanus were males. These gray monitor, Varanus griseus of both sexes were caught from the arid area of the Eastern Province of Saudi Arabia. The present study provided that Nematotaenia dispar was the only worm isolated and identified from the infected gray monitor. The present is the first record of this parasite from Saudi Arabia.

Genetic diversity of Dientamoeba fragilis isolates of irritable bowel syndrome patients by high-resolution melting-curve (HRM) analysis.

Dientamoeba fragilis is a parasite that has been recognized as a causative agent of gastrointestinal symptoms. The search for genetic variation in D. fragilis based on the small-subunit (SSU) rRNA gene using restriction fragment length polymorphism was found not useful for molecular epidemiology. In this study, genetic variability of different clinical isolates of D. fragilis was explored by high-resolution melting curve (HRM) following polymerase chain reaction (PCR) in a one-step closed-tube method. Thirty fecal samples from irritable bowel syndrome (IBS) patients having D. fragilis trophozoites and negative for other organisms were involved in this study. According to the type of diarrhea, eight patients had acute, 14 patients had chronic intermittent, and eight patients had diarrhea alternating with constipation. HRM proved that four profiles (subtypes) were present as detecting by scanning mutation. One of these profiles (profile 1) was predominant (50%). Profile 2 was present on 20%. Profiles 3 and 4 were present on 16.7% and 13.4%, respectively. No mixed profiles were detected among the samples. The melting curves characterized by T(m)1=77.17+/-0.29 degrees C in profile 1, T(m)1=77.37+/-1.45 degrees C in profile 2, T(m)1=74.24+/-0.08 degrees C and T(m)2=79.64+/-0.09 degrees C in profile 3, and T(m)1=75.51 +/- 0.09 degrees C and T(m)=79.42 +/- 0.09 degrees C in profile 4. The relation between these profiles and types of diarrhea proved that the majority of patients having profile 1 (73.4%) and profile 4 (75%) had chronic intermittent diarrhea. All of the patients having profile 2 had acute diarrhea while all of the patients having profile 3 had diarrhea alternating with constipation. Although profile 1 was detected among all types of diarrhea, it was corresponding to 11/14 of patients with chronic intermittent diarrhea. All the differences were clinically and statistically significant. In conclusion, HRM following PCR was proved as a wide variation on D. fragilis genotypes that could be related to the characters of diarrhea among IBS patients. As the differences in HRM reflect different sequences of SSU RNA gene, thus, another study for identifying the sequences of these isolates (profiles) will be done and published later.

Immunosuppressant effects of Leishmania infection in Psammomys obesus trapped in Saudi Arabia.

This study was conducted to investigate the immune status of Psammomys obesus (P. obesus) most implicated as a reservoir host of zoonotic cutaneous leishmaniasis (ZCL) in the Al-Ahsa area, Saudi Arabia. Based on the presence of amastigotes in the characteristic lesions and, rodents were divided into two groups. G1 was apparently healthy 10 rodents and G2 were infected 10 ones. Reduced leukocyte count, percentage lymphocyte and lysozome activity occurred in infected rodents compared to control ones. The infection significantly reduced the macrophage phagocytic activity reflected by two fold reduction in intravascular carbon clearance compared to control rodents. The results showed that ZCL produced an immunosuppressant effects in P. obesus.

Taxonomical studies of ticks infesting wild rodents from Asir Province in Saudi Arabia.

Ticks infesting rodents in Asir Province, which is about 3000 meter above sea level, were surveyed in Wadi Dalaghan and Wadi Bin Hachbal. They were examined from September to December 2006, where ten local life baited traps were distributed for 3 days each month. The rodents were Acomys c. dimitatus (20), Meriones rex (19) & one Gerbillus cheesmani. Fifty three nymphs were dropped off from the rodents in the laboratory 3 to 12 days post-trapping. Forty eight nymphs were reared to adults for identification and 5 ones died. The reared ticks were Rhipicephalus turanicus and R. sanguineus. The medical and veterinary importance was discussed.

Comparison between secretory leukocytic protease inhibitor and reactive nitrogen intermediates levels in cervicovaginal secretions from symptomatic and asymptomatic trichomoniasis Egyptians patients.

Although trichomoniasis is one of the most widespread sexually transmitted diseases, limited information is known about the host and parasite factors which cause symptomatic versus asymptomatic infections. Both of Secretory Leukocytic Protease Inhibitor (SLPI) and Reactive Nitrogen Intermediates (RNI) are major effectors in the innate immune response against infection. This study aimed to compare the level of SLPI and RNI in relation to the vaginal complains among trichomoniasis Egyptian patients. Two groups of trichomonas infected patients were included. Group I included 30 symptomatic patients distributed in three equal subgroups mild, moderate and severe accordiing to degree of symptoms and Group II included 10 asymptomatic patients. Besides, control Group III included 10 healthy females. Cervicovaginal levels of SLPI & RNI were determined in all patients. The mean level of SLPI was less in symptomatic patients (187.75+/-11.61 ng/ml) than in asymptomatic ones (361.18+/-53 ng/ml), with statistically significant difference. Mean level of SLPI was markedly lower in severe symptomatic patients (173.97+/--4.64 ng/ml) when compared with moderate (188.60+/-2.47 ng/ml) and mild (200.69+/-3.01 ng/ml) subgroups respectively. This difference was statistically significant. In controversy, mean levels of RNI in symptomatic patients were significantly higher (39.4+/-7.15 microM) than asymptomatic (38.89+/-6.49 microM). The mean level of RNI was significantly low in severe symptomatic (30.07+/-1.79 microM) than moderate (41.83+/-1.01 microM) and mild (46.30+/-2.02 microM) symptomatic subgroups. This difference was statistically significant. Both of SLPI & RNI levels returned to normal levels in 93.4% & 80% of symptomatic patients respectively one week after metronidazole therapeutic course.

Parasitological and immunological studies on rats experimental infected with Saudi Arabian strain of Trypanosoma evansi.

Surra, an enzootic disease caused by Trypanosona evansi, is one of the most important trypanosomiasis in Kingdom of Saudi Arabia. The state of parasitaemia in relation to the corresponding humoral response in experimentally infected Wister rats for 15 days were investigated. The prepatent period was found to be 5 days. The disease was characterized by intermittent fluctuation of parasitaemia and a significant difference in the level of parasitaemia (P > 0.05) was detected in specimens of day 7, 9, 13 & 14. There was a difference in the mean number of blood parasites in relation to sex throughout the 15 days of the study. This difference was statistically significant (P < 0.05). Using indirect haemagglutination serological test, almost all inoculated rats displayed specific antibodies of diagnostic value on day 7 after infection ranging between 1/80-1/160. Thereafter, antibody titers increased progressively to reach very high positive dilutions of > 1/2048 in all animals at the end of study on day 15. No sex difference could be observed in both serological specimens of 7 & 15 days. Also no correlation was observed between the state of parasitaemia and the serological titers in infected rats.

The presence of Aplectana nematode in the alimentary canal of Uromastyx aegyptius microlepis (Blanford, 1874) from the eastern province of Saudi Arabia.

Fifteen dabb-lizard, Uromastyx aegyptius microlepis of both sexes were caught from the arid area of the Eastern Province of Saudi Arabia. The alimentary canal was found to be infected with helminthes nematode at rate of 86%, 9% and 5% for the stomach, the small intestine and the large intestine respectively. The nematodes were identified as Aplectana species.

Production and characterization of stable amphotericin-resistant amastigotes and promastigotes of Leishmania mexicana.

The sensitivities of Leishmania mexicana amastigote and promastigote forms to amphotericin B were investigated in vitro and found to be strongly influenced by the culture media used. When differences in culture media were minimized, there was no significant difference in the 50% inhibitory concentration values between the two life cycle stages. Stable amphotericin B-resistant amastigote and promastigote lines were produced by the application of increasing drug pressure to long-term cultures. Lines capable of growth in concentrations of amphotericin B lethal to normal parasites were produced. Compared to normal parasites, these amphotericin-resistant lines showed marked differences in membrane sterol compositions, with very high levels of 4,14,dimethyl-cholesta-8,24-dienol and other methyl sterols. They also showed a consistent morphological feature, the presence of multilamellar membrane-like material in the flagellar pocket, revealed by transmission electron microscopy. Amphotericin-resistant parasites were capable of infecting BALB/c mice, but the resulting lesion growth was slower than that after infection with normal parasites. However, unlike normal parasites, the amphotericin-resistant parasites were unaffected by experimental chemotherapy with amphotericin B. These results show that amphotericin B resistance could arise as a result of increased clinical use of amphotericin B therapy.