Breast-feeding protects infantile diarrhea caused by intestinal protozoan infections.

This study investigated the effect of breast-feeding in protection against protozoan infection in infants with persistent diarrhea. Infants were classified into 2 groups; 161 breast-fed infants and the same number of non-breast-fed infants. Microscopic examinations of stool were done for detection of parasites and measuring the intensity of infection. Moreover, serum levels of IgE and TNF-α were measured by ELISA. Cryptosporidium spp., Entamoeba histolytica/Entamoeba dispar, Giardia lamblia, and Blastocystis sp. were demonstrated in infants with persistent diarrhea. The percentage of protozoan infections was significantly lower in breast-fed infants than that in the non-breast-fed infants. The levels of IgE and TNF-α were significantly lower in the breast-fed group than in the non-breast-fed group. There were significant positive associations between the serum levels of IgE and TNF-α and the intensity of parasite infection in the breast-fed group. It is suggested that breast-feeding has an attenuating effect on the rate and intensity of parasite infection.

Isolation and Identification of Pathogenic Acanthamoeba Species from Air Conditioning Systems, Egypt.

Acanthamoeba are free-living amoebae that cause granulomatous amoebic encephalitis and keratitis. In this study, we aimed to isolate and identify Acanthamoeba from air conditioning systems using in vitro cell culture and polymerase chain reaction assays. We also estimated the pathogenicity of the isolates by measuring their thermotolerance and studying mice models inoculated with these isolates. Of the 80 dust samples acquired, 41 (51.25%) were found to be positive for Acanthamoeba spp. using in vitro cell culture and the results were validated using PCR. Out of these 41 samples, 27 (65.9%) were thermotolerant and 16 (39%) samples could infect mice and cause histopathological effects. Highly pathogenic Acanthamoeba isolates were characterized by their thermotolerance and the ability to disseminate in all organs after infection, causing early death of infected animals. Our study thus validated the presence of pathogenic isolates of Acanthamoeba in air conditioners that may be potentially infectious to humans.

Transplantation of skin grafts and organs infected with Toxoplasma gondii as a source of toxoplasmosis in immunocompromised mice.

The possibility of Toxoplasma gondii infection resulting from transplantation of a skin graft and various organs has been investigated. The parasite was detected in very low numbers in all organs examined in wild-type (WT) BALB/c (B/c) mice that received skin grafts from infected interferon gamma knockout (GKO) B/c mice both with and without sulfamethoxazole treatment; all recipient mice survived. In contrast, transplantation of skin grafts from untreated infected WT B/c mice to naïve GKO B/c mice led to the death of all recipients within 20 days post-transplantation; T. gondii was found to be disseminated in all organs examined. Similar results were obtained after transplantation of skin from untreated and treated GKO B/c mice to naïve GKO B/c mice, whereas the recipient GKO B/c mice died within 10 days after intraperitoneal transplantation of lung, heart, brain or small intestine from infected untreated GKO B/c mice. These results indicate that skin grafts as well as various organs infected with T. gondii can be sources of infection in immunocompromised hosts. Toxoplasmosis should therefore be taken into consideration during organ transplantation to immunocompromised hosts.