The requirements for effective and efficient intracellular killing of Leishmania amazonensis by activated macrophages are unknown. Despite resistance to the arginase inhibitor LOHA by intracellular L. amazonensis amastigotes, enhanced replication did not account for the relative resistance of this parasite to macrophage activation. Herein we report that the presence of both superoxide and nitric oxide is necessary for efficient killing of L. amazonensis amastigotes within LPS/IFN-gamma-activated bone marrow-derived macrophages generated from C3H mice. Addition of an extracellular signal-regulated kinase (ERK) inhibitor to L. amazonensis-infected macrophages increased the ability of these activated macrophages to kill L. amazonensis amastigotes. This enhanced macrophage killing through addition of ERK inhibitor was abrogated by inhibition of superoxide or iNOS, whereas inhibiting superoxide had no effect on the killing of L. major. These results suggest that ERK activation may modulate effective macrophage killing, leading to the ability of L. amazonensis to resist elimination within activated macrophages.

(Mukbel R). #Joint first authors Highlights First genotyping study of Cryptosporidium in animals in Jordan  Faecal samples (n=284) from domestic animals and humans (n=48) screened  Overall prevalence of 11.6% in animals and six species detected.  Novel Cryptosporidium genotype detected in horses AbstractLittle is known about the epidemiology of Cryptosporidium in Jordan and to date, only one genotyping study has been conducted on Cryptosporidium isolates from Jordanian children. In the present study, a total of 284 faecal samples from Jordanian cattle, sheep, goats and chicken and 48 human faecal samples were screened for the presence of Cryptosporidium using an 18S quantitative PCR (qPCR) and a C. parvum/C. hominis specific qPCR at a lectin locus. Of these, 37 of 284 animal faecal samples were positive by qPCR at the 18S locus giving an overall prevalence of 11.6%. The point prevalence of Cryptosporidium in chickens, sheep, horses, cattle and goats ranged from 4.8% (chickens) to 18.7% (cattle). A total of six species were detected; C. xiaoi (n=9), C.andersoni (n=7), C. ryanae (n=5), C. parvum (n=4), C. baileyi (n=1) and a genetically distinct and potentially novel species in two isolates from horses. Sub-genotype analysis of the 4 C. parvum isolates at the 60-kDa glycoprotein (gp60) locus identified subtype IIaA19G2R1 (n=2) and IIaA16GR1 (n=2). For the human samples, 4 positives (8.3% prevalence) were detected. Of these, two were C. parvum (subtypes IIdA20G1 and IIaA15G2R1) and two were C. hominis (subtypes 1bA9G3 and 1bA10G2R2). Further studies are required to better understand the epidemiology and transmission of Cryptosporidium in Jordan.

The purposes of this study were to estimate the seroprevalence and distribution of horse piroplasmosis, to evaluate risk factors associated with the occurrence of the disease and to compare the different diagnostic methods used for this disease. A total of 253 clinically normal horses were sampled, and a collection form was completed for each horse from five of six different climatic zones of Jordan. The sixth zone was not sampled because it did not include horse population. Competitive enzyme-linked immunosorbent assay (cELISA) revealed 37 horses (14.6%) positive for Theileria equi, and none of the horses was positive for Babesia caballi. Microscopic examination of thin blood smears and PCR test revealed no positive results for either parasite. Grazing was the only risk factor that was associated with being seropositive to the disease; horses that graze are 11.5 more likely to be seropositive (P<0.05, OR=11.5, CI: 3.292, 39.962). This is the first study to estimate the prevalence of horse babesiosis using serological test and to identify risk factors associated with the disease in Jordan. Competitive enzyme-linked immunosorbent assay (cELISA) test appears to be more reliable than microscopic examination and PCR in estimating the seroprevalence of the disease as well as identifying carrier horses to babesiosis.

AVL was identified in 19.5 % of OIF deployers and travel to northwest Iraq correlated with infection. Further studies are needed to inform risk for reactivation VL in U.S. veterans and to target additional blood safety and surveillance measures.

BackgroundSand fly saliva can drive the outcome of Leishmania infection in animal models, and salivary components have been postulated as vaccine candidates against leishmaniasis. In the sand fly Phlebotomus papatasi, natural sugar-sources modulate the activity of proteins involved in meal digestion, and possibly influence vectorial capacity. However, only a handful of studies have assessed the variability of salivary components in sand flies, focusing on the effects of environmental factors in natural habitats. In order to better understand such interactions, we compared the expression profiles of nine P. papatasi salivary gland genes of specimens inhabiting different ecological habitats in Egypt and Jordan and throughout the sand fly season in each habitat.ResultsThe majority of investigated genes were up-regulated in specimens from Swaymeh late in the season, when the availability of sugar sources is reduced due to water deprivation. On the other hand, these genes were not up-regulated in specimens collected from Aswan, an irrigated area less susceptible to drought effects.ConclusionExpression plasticity of genes involved with vectorial capacity in disease vectors may play an important epidemiological role in the establishment of diseases in natural habitats.