STUDIES ON THE IMMOBILIZATION REACTION IN THE GENUS BALANTIDIUM

Comparative study of three xenic media culture for cultivation of Balantidium coli strains

The aim of the present study was to evaluate the growth rate of Balantidium coli in three xenic media cultures. Between 2013 and 2015, 10 B. coli isolates obtained from feces of Cynomolgus macaques, and 30 isolates from feces of pigs were studied. An inoculum of 500 trophozoites was transferred to tubes containing LES, TYSGM-9 and Pavlova media. These cultures were evaluated at incubation times of 24, 48, 72 and 96 hours. In most of strains analyzed wasn't showed significant difference in the growth rate comparing TYSGM-9 and Pavlova media (Wilcoxon p>0.016). In Pavlova medium, the trophozoites showed a maximum growth at 72 hours with significant difference when compared with the times of 24 h and 96 h (Wilcoxon <0.008). In LES, viable trophozoites were observed until 24 hours, with a significant difference (Friedman p<0.05, Wilcoxon p<0.016) in the number of parasite cells compared with Pavlova and TYSGM-9 media cultures. Thus, LES medium seemed to be less adequate than the other media for maintenance of B. coli. Despite the satisfactory results in TYSGM-9, Pavlova medium was considered ideal for the maintenance of this protozoan strain, guaranteeing the viability of the parasite with subculture every three days, presenting lower costs.

Isolation and maintenance of Balantidium coli (Malmsteim, 1857) cultured from fecal samples of pigs and non-human primates

Balantidium coli is a protozoa that can determine dysentery in humans, pigs and non-human primates having zoonotic potential. The lack of standardization in isolation and maintenance hinders the development of research on its biology and epidemiology. This study is aimed to standardize the isolation and maintenance of this parasite from animal feces, in culture medium, Pavlova modified. From 2012 to 2014, 1905 fecal samples were collected from captive animals of Rio de Janeiro. Were selected for isolation samples with a minimum of 10 trophozoites and/or 30 cysts of B. coli, totaling 88 pigs, 26 Cynomolgus and 90 rhesus macaques. In the presence of cysts, the sample was homogenized in saline solution, 500 μL was removed and inoculated into culture medium. The material that contained trophozoites the inoculum was made from 240 μL of fecal solution. All inoculate tubes with the subcultures were kept at 36°C, and sterile rice starch was always added to the medium. The parasites isolate from pigs, 34%, and from Cynomolgus 38.4% were maintained in vitro for a period of more than 24 months. These procedures proved to be adequate for isolation and maintenance of B. coli from different animals, they were found to be inexpensive and easy to perform.

Current world status of Balantidium coli

Balantidium coli is a cosmopolitan parasitic-opportunistic pathogen that can be found throughout the world. Pigs are its reservoir hosts, and humans become infected through direct or indirect contact with pigs. In rural areas and in some developing countries where pig and human fecal matter contaminates the water supply, there is a greater likelihood that balantidiosis may develop in humans. The infection may be subclinical in humans, as it mostly is in pigs, or may develop as a fulminant infection with bloody and mucus-containing diarrhea; this can lead to perforation of the colon. The disease responds to treatment with tetracycline or metronidazole. Balantidiosis is a disease that need never exist given access to clean water and a public health infrastructure that monitors the water supply and tracks infections. Its spread can be limited by sanitary measures and personal hygiene, but it is a disease that will be around as long as there are pigs. Immunocompromised individuals have developed balantidiosis without any direct contact with pigs, perhaps with rats or contaminated produce as a possible source of infection. For the clinician, balanatidiosis should be included in the differential diagnosis for persistent diarrhea in travelers to or from Southeast Asia, the Western Pacific islands, rural South America, or communities where close contact with domestic swine occurs. Warming of the earth's surface may provide a more favorable environment, even in the now-temperate areas of the world, for survival of trophic and cystic stages of Balantidium, and its prevalence may increase. Effective sanitation and uncontaminated water are the most useful weapons against infection. Fortunately, balantidiosis responds to antimicrobial therapy, and there have been no reports of resistance to the drugs of choice.

Invasive balantidiasis presented as chronic colitis and lung involvement

A unique case of chronic balantidiasis is described, presenting with chronic colitis and inflammatory polyposis of the rectum and sigmoid colon and an intrapulmonary mass. Histology of the colonic polyps showed Balantidium coli, and both Aspergillus and Balantidium coli were found in the aspirate of the pulmonary mass. The patient was treated with doxycycline HCl 100 mg/day for 10 days with complete clinical recovery and marked improvement of the endoscopic appearance of the colonic mucosa.

[Immunological Tests By Anti-Free-Living Amoebas Serum Produced In Experimental Animals: I. Immobilization Of Free-Living Amoebas In Vitro By Rabbit Antiserum]

Rabbits were immunized with free-living amoebas by intravenous injections. The amoebas were Acanthamoeba culbertsoni and Naegleria fowleri and obtained by axenic cultivation in CGVS medium. Each rabbit received 10(6) of Acanthamoeba culbertsoni and 10(5) of Naegleria fowleri trophozoites respectively every other day in three doses and finally one booster dose at 1 week later. Antiserum was collected from thc following day of the booster injection up to 2 months period, and stored at -30 degrees C until use. The immobilization test was performed. One drop of amoeba suspension was mixed with the test serum on slide and observed the mobile state under microscope. 1. Maximal immobilizing phenomenon observed in 30 minutes and, then gradually recovered to normal state. 2. Inactivation of antiserum at 56 degrees C for 30 minutes did not affect the immobilization phenomenon. 3. The immobilization rates decreased by the serial dilution of antiserum. At dilution more than 1:8, the immobilization was almost the same as in the normal serum. 4. The immobilizing antibody in anti-Acanthamoeba culbertsoni rabbit serum showed highest titre in 3rd day after booster immunization and from first to 6th week in anti-Naegleria fowleri rabbit serum. 5. Cross matching of Acanthamoeba culbertsoni and Naegleria fowleri showed antigenic difference of the two species. It is suggested that the immobilization reaction may be of value as a supplementary test in the diagnosis of primary amoebic meningoencephalitis.

[Immobilization-Agglomeration Reaction For The Diagnosis Of Trichomonas Vaginalis Infection]

The Trichomonas immobilization-agglomeration reaction was studied using the sera from women with vaginal trichomoniasis and from rabbits inoculated with cultures of T. vaginalis. It was found that the greatest amount of immobilization occurred at 25 to 30 minutes, and that inactivation of the sera did not affect the results. An evidence of antigenic differences between T. vaginalis, T. hominis and C. albicans was confirmed. The immobilization reaction was positive in 80.3% of the 71 T. vaginalis positive cases, but in only 7.7% of the 77 persons of T. vaginalis negative cases. From the above results, it is suggested that immobilization reaction is a useful tool for the diagnosis of T. vaginalis infection.