Trypanosoma cruzi persistence at oral inflammatory foci in chronic chagasic patients

The persistence of Trypanosoma cruzi in seropositive individuals, previously diagnosed as chronic chagasic patients (CCP), was detected for the first time in biopsies taken from gingival inflammatory foci processed by polymerase chain reaction (PCR). Seven out of 31 (22.5%) gum samples from selected unquestionably CCP showing different degrees of gingival inflammation revealed T. cruzi-DNA using 3 specific PCR assays. All the included CCP had been diagnosed in previous studies carried out over the last 19 years. Samples of inflamed gums were recently taken from the indicated patients at: an outpatient hospital cardiac unit; a village where Chagas disease is endemic; and a specialized diagnostic research center, showing molecular evidence of parasite persistence in 17.6%, 42.8% and 14.3% of them, respectively. The relatively frequent parasite persistence, demonstrated here in oral inflammatory processes of treated and/or untreated patients bearing long term T. cruzi-infection, suggests the establishment of secondary small foci for the maintenance of hidden or inapparent chagasic infection. The easy and low-risk, non-invasive method to get the sample may add the use of gingival biopsy as a potential alternative diagnostic tool to confirm T. cruzi-infection in CCP. The significance of T. cruzi persistence as a primary cause of chronic Chagas disease and the proposal of this mechanism to explain the pathogenesis in CCP are considered.

[A case of gingival myiasis in a lamb caused by the Wohlfahrtia magnifica (Diptera: Sarcophagidae)]

Gingival myiasis was found in a 4-5-months lamb which was brought to the surgical clinic of the Veterinary Faculty of Kirikkale University due to a wound in its mouth. Eleven larvae were collected from lamb's gums. The larvae were identified as the third stage larvae of Wohlfahrtia magnifica.

PCR detection of specific Leishmania-DNA in patients with periodontal disease

This study deals with the detection of Leishmania braziliensis DNA in gingival specimens from 10 individuals who all had suffered from cutaneous leishmaniasis 5-10 years prior to the examination and all had been treated with anti-leishmaniasis drugs. This preliminary study gives an interesting contribution to the oral microbiology of this disease, with the observation that inflamed periodontal tissues can serve as a factor affecting the dispersion of Leishmania parasites in individuals who had suffered from cutaneous leishmaniasis. These finding are corroborated by the results of polymerase chain reaction (PCR) which demonstrated the presence of Leishmania DNA in tissue samples of patients with periodontal diseases.

Detection and identification of Entamoeba gingivalis by specific amplification of rRNA gene

A pair of oligonucleotide primers were designed from the nucleotide sequence of the gene encoding the small subunit ribosomal RNA (SrRNA) of the oral protozoan parasite Entamoeba gingivalis. The primers amplified a 1.4-kb DNA fragment by polymerase chain reaction and were specific for Entamoeba gingivalis but not for other protozoa, oral protists and bacteria, or human leukocytes. With this method, the DNA from as few as 30 cells of Entamoeba gingivalis could be detected. These results suggest that this approach is applicable to the detection and identification of Entamoeba gingivalis in the human oral cavity.

Frequency of Entamoeba gingivalis among periodontal and patients under chemotherapy

This study was carried out to investigate the frequency of E. gingivalis in the gingival crevices of patients with periodontitis compared to normal subjects. Flagyl therapy was tried in cases with periodontitis. Also the frequency of this amoeba was investigated in patients receiving chemotherapy to be compared to normal subjects. The results revealed that higher frequency was observed in patients with periodontitis and flagyl therapy reduced this frequency. Cases under chemotherapy showed higher frequency than the normal control. Histopathological sections from the gingiva of periodontitis patients did not show any amoeba invading the tissue.

Effects of migrating Gasterophilus intestinalis larvae (Diptera: Gasterophilidae) on the mouth of the horse

Lesions were formed in the mouth of the horse by first- and second-stage Gasterophilus intestinalis larvae. The lesions resulted as larvae burrowed through the top millimeter of the tongue and then became embedded in the interdental gingiva. Appearance of the lesion was dependent on the degree of larval burrowing activity and healing that had taken place. Active tunneling production occurred at the posterior end of the lesion. Extensive change in configuration and color was apparent along the longer lesions with active larvae. Virtually all tissue in the path of the larvae was removed while forming a tunnel. Tissue destroyed included tops of the lamina propria mucosae evaginations and the deeper portions of the lamina epithelialis mucosae. Histopathologic findings showed that the tissue removed included the nerve and blood supply of the proprial evaginations. Hemorrhage and exocytosis into the tunnels included erythrocytes mixed with some macrophages, lymphocytes and scant numbers of eosinophils. Air shafts excavated in the tongue by larvae enabled bacteria to enter into the tunnels. Bacteria became adhered to larvae and initiated microabscesses. Microabscesses were composed of clotted erythrocytes, bacteria, disintegrating epithelial cells, and large numbers of neutrophils. Cells surrounding the tunnel exhibited pyknosis, epithelial hydropic degeneration and became separated from each other. Healing of tongue lesions occurred as epithelial cell growth below raised the tunnel upward and affected tissue desquamated. Interdental gingiva invaded by larvae were hyperemic and denuded of epithelia. Recession and ulceration of the gingiva produced periodontal pockets. Extensive invasion by larvae led to compound periodontal pockets. Larval mouth hooks were embedded in the submucosa of the pockets and tore at engorged capillaries. The cephalic portion of embedded larvae became surrounded by a cellular exudate containing erythrocytes and mononuclear cells. Attachment of second-stage larvae at the root of the tongue did not produce observable damage.

Parasites found in the mouths of inhabitants of three villages of South Kalimantan (Borneo), Indonesia

Infection rates of parasites in the oral cavity were compared for two study areas in South Kalimantan, Indonesia. Penguiran and Sungai Baru, two adjacent villages, were considered a single study area and were inhabited by 151 individuals ranging from 2 to 70 years. Tanah Intan, the second study area, had a population of 265 persons who also ranged from 2 to 70 years. The standard of living was low in all the villages (average of 450 U.S. dollars per family per year). Teeth and gums were examined by standard diagnostic techniques. Material from infected gums was examined for parasites. Of the 373 individuals studied, 49 were infected with Entamoeba gingivalis, 1 with Entamoeba histolytica, 19 with Trichomonas tenax, and 14 with Candida sp. The infection rates in the first study area were substantially lower than in the second study area.

Frequency of Entamoeba gingivalis in human gingival scrapings

A survey was made of gingival scrapings stained by the Papanicolaou method to assess the occurrence of Entamoeba gingivalis, a nonpathogenic-oral amoeba. Positive findings were recorded in 59% of 113 dental patients, and 32% of 96 healthy controls. These figures showed no significant changes during the last 20 years when compared with data published in 1960 and 1963. The existence of E. gingivalis and its rare appearance in the sputum should be known to cytologists because of the morphologic resemblance to Entamoeba histolytica, a pathogenic amoeba. Morphologic features are described to differentiate E. gingivalis from similar structures found in sputum.