Intestinal parasitic protozoan diseases in Saudi Arabia are a significant public health problem with prevalence ranging from 4.1% to 42%. This study was carried out to determine the risk factors associated with the prevalence of intestinal parasitic protozoan infections among patients in Ad-Dawadimi General Hospital, Saudi Arabia. This study was conducted from the 1st of January to the end of December 2015. Faecal specimens from 4,000 patients who were admitted to Ad-Dawadimi General Hospital during the study period were analyzed by the formal-ether concentration technique to detect trophozoites and cysts of Giardia lamblia and Entamoeba histolytica. Ziehl-Neelsen staining was used to detect Cryptosporidium oocysts. Overall, intestinal parasitic protozoans were found in 470 patients (11.75%). The infection rate of Giardia lamblia, Cryptosporidium spp. and Entamoeba histolytica/dispar was 5%, 4.3% and 2.5%, respectively. Infection among males was (8.4%), while among females it was (3.4%). Age, gender and season were highly significant factors on the prevalence of parasites infection at P <0.005. However, the present study indicated that intestinal parasitic protozoan infections are still a public health problem in Saudi Arabia.

This study aimed to consider the in vitro and in vivo effects of the Stachys lavandulifolia methanolic extract (SLME) (2.5, 5, 10, 25, 50, 100 µg/mL) against Leishmania major infection. The in vitro antileishmanial effects of SLME was studies on promastigote and amastigote forms of L. major. The effect of SLME on the nitric oxide (NO) and apoptosis, secretion of Th1/2 cytokines, and infectivity rate in macrophages cells were also studies. The cytotoxicity of SLME on human (THP-1) and murine (J774-A1 cell) macrophage cells was investigated through the measuring the 50% cytotoxic concentrations (CC50). Moreover, the in vivo effects of SLME for healing the cutaneous leishmaniasis (CL) lesions in infected BALB/c mice studied by assessing the lesions size and the parasite load during four weeks of treatment. The calculated 50% inhibitory concentration (IC50) valuesfor SLME and meglumine antimoniate (MA) against the promastigote stage were 23.4 and 71.1 µg/mL, respectively. For amastigote stage, the IC50 values for SLME and MA were 39.3 µg/mL and 44.3 µg/mL, respectively. Followed by 28 days’ topically therapy with SLME at doses of 50 and 100 mg/kg/day, the CL lesions size as well as parasite load were significantly (p<0.001) reduced; such that the recovery percentage of the infected mice was 80% and 97% after treatment with SLME at the dose of 50 and 100 mg/kg, respectively. SLME also markedly induced the NO production and apoptosis; whereas decreased infection rate in macrophage cells. After incubation of infected macrophages with SLME, the level interferon gamma was meaningfully (p<0.001) elevated as a dose-dependent response; in contrast, release of interleukin 10 (IL-10) and IL-4 markedly (p<0.001) decreased. The CC50 value for SLME against THP-1 and J774-A1 cell was 996.4 µg/mL and 741.3 µg/mL, respectively. The calculated selectivity index of >10 for SLME and MA confirmed their specificity to amastigotes and the low toxicity for macrophages. Our results showed the potent effects of SLME in eliminating and controlling Leishmania parasites in both in vitro and in vivo assays. Based on the current experimental study, SLME can be suggested as an alternative medicine for the isolation and production of a new agent for treating CL caused by L. major. Although, we found some cellular mechanisms of SLME against Leishmania parasites, but, additional surveys are necessary to specify the accurate mechanisms of action, toxicity, and its efficacy mainly in human subjects.

Leishmaniasis is an infectious disease with various clinical manifestations. We studied the therapeutic effects of Elettaria cardamomum essential oil (ECEO) against Leishmania major infection. In vitro effects of ECEO against L. major were examined by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) and macrophage assays. Nitric oxide (NO) production, infection inhibition in macrophages, and the apoptotic activity of ECEO in treated parasites were also measured. By calculating the 50% cytotoxic concentrations (CC50), we studied the cytotoxicity effects of ECEO on human macrophage cells (THP-1). The efficacy of ECEO for improving cutaneous leishmaniasis (CL) lesions in mice (BALB/c) was determined by evaluating the size of lesions and the number of amastigotes before and after four weeks of treatment. The effects of ECEO on liver and kidney function in the tested mice were also evaluated. ECEO dose-dependently (p<0.001) inhibited the viability and the mean number of promastigotes and amastigote forms of L. tropica. Four weeks of treatment with ECEO at the doses of 2.5 and 5 mg/kg/ day significantly (p<0.001) improved the CL lesions and reduced the number of parasites in the infected mice. ECEO significantly increased NO production, apoptosis induction, and infection rate in parasites. The CC50 value for ECEO and MA was 303.4 µg/mL and 835.2 µg/mL, respectively. In the mice receiving ECEO at the doses of 2.5 and 5 mg/kg/day for 28 days, no significant change was reported between the serum level of liver enzymes and kidney factors when compared with the control group. ECEO displayed promising efficacy in parasite reduction in vitro and in the animal model. ECEO can thus be used as an alternative medicine to treat CL.

Dogs can act as a reservoir of canine leishmaniasis disease, which is caused by Leishmania species. The study aimed to identify and document the genotype of cutaneous leishmaniasis (CL) in the stray dogs in Riyadh Province using kinetoplast DNA (kDNA) as a target gene by using nested polymerase chain reaction (nPCR). This cross-sectional investigation was conducted over the course of two years, from March 2016 to July 2018, in different districts of Riyadh Province, Saudi Arabia. A total of 237 dogs were examined, only 18 of the dogs were suspected clinically of cutaneous leishmaniasis due to the presence of cutaneous nodules and cutaneous lesion. Biopsy tissue collections were performed and DNA was extracted. CSB2XF and CSB1XR primers were used to amplify the Leishmania kDNA regions. The Leishmania species were detected by specific 13Z and LIR primers by applying nested PCR assay. Nine dogs were found to be positive for Leishmania major. The examined dogs were negative for other Leishmania spp. The phylogenetic analysis and blast results of kDNA showed that the 9 isolates L. major is closely related (99.9%) to the L. major isolate CMG_irfan5, accession number HQ727556.1 from human, Pakistan. This is the first molecular study on dog leishmaniasis from Saudi Arabia confirmed that dogs have a L. major infection. Further epidemiological and molecular investigations are required to study domestic and wild canine infections with L. major and other Leishmania spp in endemic and nonendemic areas of Saudi Arabia as part of leishmaniasis control

We aimed at determination of acaricidal, larvacidal, and repellent activities of green synthesized silver nanoparticles (SNP) against Hyalomma dromedarii as one of the most common ticks in camels. SNP were green synthesized by reducing Lupinus albus extract through the precipitation technique. The acaricidal, larvicidal, and repellent activity of SNP against H. dromedarii was studied through the adult immersion test (AIT), the larval packet test (LPT), the vertical movement behavior of tick’s larvae method, anti-acetylcholinesterase (AChE) activity, and oxidative enzyme activity. The green synthesized SNP displayed a spherical form with a size ranging from 25–90 nm; whereas the most distribution of particles size was reported at 50-65 nm. SNP dose-dependently (p<0.001) increased the mortality rate of H. dromedarii adult; whereas at 16 and 32 µg/mL completely killed the adult females. Treatment of exposure of H. dromedarii adult to SNP markedly (p<0.001) declined the mean number, weight, and hatchability of eggs. Treatment of H. dromedarii larvae with SNP reduced the viability rate of larvae with the LC50 and LC90 values of 3.1 and 6.9 µg/mL, respectively. Exposure of H. dromedarii larvae to SNP, especially at ½ LC50 and LC50, markedly (p<0.001) increased the oxidative stress and declined the level of antioxidant enzymes in H. dromedarii larvae; whereas, markedly suppressed the AChE activity of the larvae stage of H. dromedarii in comparison to the control group. These results showed that SNP green synthesized by L. albus extract had promising acaricidal, larvicidal and repellent activity against H. dromedarii adults and larvae as a dose-dependent response. SNP also considrably decreased the level of acetylcholinesterase and antioxidant activity and also provokes oxidative stress in H. dromedarii larvae. However, more investigation must be designed to clear the accurate mechanisms and the efficacy of SNP in practical use.

Lack of knowledge about the type and prevalence of gastrointestinal symptoms as a clinical manifestation is one of the reasons for delayed diagnosis and treatment of COVID-19 patients. This review study aimed to systematically review the type and prevalence of gastrointestinal symptoms in COVID-19 patients. To study the gastrointestinal manifestations of COVID-19, we used the 06- PRISMA registered in the CAMARADES-NC3Rs Preclinical Systematic Review and Meta-Analysis Facility (SyRF) database. PubMed, Embase, Web of Science, Google Scholar, and Scopus databases were searched for publications on the gastrointestinal manifestations of COVID-19 with no publication time frame. Articles were found using the following terms and search strategy: [“COVID-19, Coronavirus, 2019-nCoV, Clinical SymptomsGastrointestinal or gastric or intestinal manifestations”]. Out of 27652 papers, 35 papers on a total of 6730 COVID-19 patients up to 2022 met the inclusion criteria. Remarkably, most articles (28 papers, 77.8%) were from China (77.8%). The most common gastrointestinal manifestations were nausea or vomiting (13.1%), diarrhea (11.05%), anorexia (8.7%), and abdominal pain (2.4%), respectively. The findings of the present review revealed that contrary to what was initially assumed in the COVID-19 outbreak, this infection does not manifest only as respiratory symptoms but also as gastrointestinal symptoms. Therefore, clinicians and gastroenterologists must be alert to these unusual cases and fecal–oral transmission during the COVID-19 pandemic and implement preventive strategies.

Knowledge of molecular identification of tick-borne pathogens in camels in Saudi Arabia is very limited; few molecular epidemiological studies have been under taken. This study was to detect Anaplasma spp. and Piroplasma spp. in camels from Asir Province, Saudi Arabia. A total of 150 blood samples were collected from camels in Asir Province and investigated by polymerase chain reaction (PCR) that targeted 18S rRNA and 23S rRNA to detect the DNA of Piroplasma spp. and Anaplasma spp., respectively. The positive samples for 23S rRNA were assayed again by PCR targeting the 16S rRNA. All the blood samples were free from Piroplasma spp. infection. Three camels (2%) were found to be positive for Anaplasma infection through use of PCR that targeted the 23S rRNA gene. There were no significant differences between ages or sexes in the camels that tested positive for Anaplasma. All positive Anaplasma infections were recorded in camels that were infested by ticks. Two Anaplasma sequences for the16S rRNA gene were deposited in GenBank with accession numbers MN882724 and MN882725. They recorded 99.16% and 99.34% similarities (respectively) with KF843825.1 (Candidatus Anaplasma camelii reported in Unizah, Saudi Arabia). Phylogenetic analyses revealed that the two sequences recorded in this study were close to each other; both were located in one cluster with Candidatus Anaplasma camelii isolates that were recorded before in the adjacent areas of Unizah in Saudi Arabia and Iran. In conclusion: two new Anaplasma genotypes close to Candidatus Anaplasma camelii were found in camels in Asir Province, Saudi Arabia for the first time. The camels in this province were found to be free of Piroplasma infection.