Leishmania donovani is one of the causative agents of visceral leishmaniasis. The immune response against Leishmania depends on CD4⁺ T helper type 1 cells. The immune system is unable to combat Leishmania because the parasite can exert several immune suppressive mechanisms that facilitate escaping the immune responses. One of these mechanisms is the up-regulation of programmed death-1/programmed death ligand-1 pathway which causes T cells to undergo exhaustion. Autophagy is strongly linked to the immune response, with some research indicating that activating autophagy reduces the immune response to some intracellular pathogens, while others indicate that activating autophagy limits the growth of intracellular pathogens. Leishmania was found to subvert the host defense mechanisms for its own persistence, such as Leishmania-induced autophagy modulation. Leishmania was reported to activate autophagy in different studies, thus getting a dual benefit by evading the immune system and simultaneously utilizing the autophagy byproducts as nutrients. In this review, we introduced different immune evasion/suppressive mechanisms used by Leishmania, and different immunotherapies which were developed accordingly. We focused on the programmed death-1/programmed death ligand-1 pathway as well as autophagy with the potential interplay of both mechanisms.

Objective: To study the spectrum and outcome of severe scrub typhus in adult patients and to predict the hospital mortality by organ failure on admission. Methods: This was a prospective observational cohort study conducted between July 2017 and October 2020 at the medical emergency centre of PGIMER, Chandigarh, India. One hundred and twenty-six patients aged ≥13 years were diagnosed with scrub typhus. Severe disease was defined as the presence of organ failure based on the Sequential Organ Failure Assessment (SOFA) score on admission. Results: About two-thirds of the patients were from geographic regions outside the endemic sub-Himalayan belt. Fever (99.21%) and dyspnea (79.36%) were the most frequent complaints. Respiratory failure (81.75%) was the most common organ failure, followed by hepatic (52.38%), coagulative (47.62%), circulatory (33.33%), renal (21.43%), and cerebral dysfunction (13.49%). The median (Q1, Q3) SOFA score was 8 (6, 9), and 48.41% of the patients had a quick-SOFA score ≥2. Organ supports with invasive ventilation (40.48%), vasopressors (36.51%), and renal replacement therapy (7.14%) were frequently required. The in-hospital mortality was 11.90% and was independently predicted by circulatory and hepatic failures on multivariate logistic regression (OR 11.12, 95% CI 1.73-71.31 and OR 8.49, 95% CI 1.18-61.41, respectively). Conclusions: Most patients had pulmonary dysfunction; circulatory or hepatic failure on admission strongly predicts death.

Objective: To examine and study the morphology, epidemiology, and molecular phylogeny of Anisakis larvae in blue mackerel [Scomber australasicus (Cuvier, 1832)] and Indian mackerel [Rastrelliger kanagurta (Cuvier, 1816)] using light microscope, scanning electron microscope, molecular phylogeny, and species delimitation methods for confirmation and investigation of Anisakis species and their evolutionary relationship. Methods: A total of 90 fish (45 per species) were purchased from a department store in Chiang Mai, Thailand. Anisakis samples were investigated for morphological characteristics using light and scanning electron microscopes. Molecular phylogeny and species delimitation methods based on the cox2 gene were performed. Results: The prevalence, mean intensity (Mean±SEM), and mean abundance of Anisakis larvae (Mean±SEM) in blue mackerel were 77.78%, 6.74±1.320, and 5.24±1.107, respectively, and in Indian mackerel, these values were 13.33%, 2.50±0.764, and 0.33±0.159, respectively. Scanning electron microscopy showed the detail of morphological characteristics and provided the different shapes of mucron and excretory pores in Anisakis larvae congruent with the phylogenetic tree. The species tree was congruent with the phylogenetic tree. Conclusions: The prevalence, mean intensity, and mean abundance of Anisakis larvae were higher in blue mackerel. To the best of our knowledge, this is the first time that Anisakis pegreffii was found in blue mackerel in Thailand. The phylogenetic tree also supported the morphological data of Anisakis larvae. However, species delimitation based on cox2 revealed 1-3 possible cryptic species in this genus. Anisakis spp. contamination of fish products is unpleasant and a health concern considering human infection with larvae (anisakiasis) arises.

Objective: To estimate the infection of ticks to Anaplasma, Ehrlichia, Babesia, Theileria, and Brucellaceae using molecular methods in borderline of Iran, Azerbaijan, and Armenia. Methods: Totally, 2 022 ticks were collected from different livestock. Then, species were diagnosed under stereomicroscope according to valid morphological keys. Tick DNA was extracted followed by PCR to detect Anaplasma, Ehrlichia, Theileria, Babesia and Brucellaceae infection in ticks. Results: A total of 498 males [24.62% (95% CI 22.76%-26.57%)], 741 females [36.64% (95% CI 34.54%-38.79%)], 782 nymphs [38.67% (95% CI 36.55%-40.84%)] and 1 larva [0.04% (95% CI 0.00%-0.28%)] were identified. Among identified samples, we found four genera including Hyalomma, Rhipicephalus, Haemaphysalis, and Dermacentor. Molecular assay revealed that the prevalence of ticks to Anaplasma or Ehrlichia, and Brucellaceae was 22.02% (95% CI 16.01%-29.06%) and 15.03% (95% CI 9.43%-22.26%), respectively. Phylogenetic analysis showed that the identified Anaplasma sp. had the most similarity with Anaplasma centrale, Anaplasma platys, Anaplasma camelii, and Anaplasma phagocytophilum, submitted in GenBank. Furthermore, the detected Ehrlichia sp. and Brucellaceae bacterium had the most similarity with Ehrlichia ruminantium and Mycoplana peli, respectively. However, no sign of the presence of Theileria and Babesia spp. was seen in the studied samples. Conclusions: Anaplasmosis, ehrlichiosis and brucellosis should be considered as important health threats in northwestern Iran and consistent monitoring on infection of ticks and livestock should be performed regularly.

Rationale: Salmonella (S.) typhi is a rare cause of osteomyelitis in immunocompetent adults. Extensive drug resistance (XDR) may lead to more complicated cases of S. typhi osteomyelitis. Patient concern: A 55-year-old female presented with a persistent low-grade fever and a swelling on her lower left chest with a sinus discharging purulent fluid for the past 8 months. Her symptoms had been unresponsive to previous anti-microbial therapy. Diagnosis: Rib osteomyelitis caused by XDR S. typhi. Interventions: Surgical wound debridement, left 7th-9th rib resection and intravenous IV meropenem were done. Outcome: Fever resolved and left-sided swelling resected without recurrence. Lessons: The prevalence of XDR S. typhi is growing in South Asia and should be considered as the differential diagnosis of chronic osteomyelitis.