Leishmania (Viannia) panamensis - induced cutaneous leishmaniasis in susceptible and resistant mouse strains

We studied the susceptibility to Leishmania (Viannia) panamensis in strains of mice. The C57BL/6 strain was resistant and showed self-controlled lesion at the injected foot pad. The BALB/c and DBA/2J strains were susceptible and showed a foot swelling that started day 20 post-infection and progressed to a tumour-like lesion in later period of observation. The CBA/HJ strain was found to be of intermediary resistance. In contrast to other known cutaneous leishmaniasis in mice, the lesion in L. (V.) panamensis-infected mice was restricted to the inoculation site in the skin. In addition, we studied the development of cellular response and antibodies against Leishmania antigen in BALB/c and C57BL/6 strains. The proliferative response of lymph node cells against L. (V.) panamensis antigen was biphasic in both strains. An initial response was seen on day 20, followed by a refractory period between 40 and 80 days and a second response around fourth month post-infection. The response in the latter period was higher in C57BL/6 strain than in BALB/c strain. BALB/c strain presented much higher anti-Leishmania antibody level than C57BL/6 strain. The model and the correlation of immunological variables and the course of the infection are discussed.

Scorpion sting epidemiology in Montes municipality of the State of Sucre, Venezuela: geographic distribution

Scorpion stings were surveyed in the Montes Municipality of the State of Sucre, Venezuela, aiming to extend the information on these poisonous accidents by characterizing their geographic distribution. From 1980 to 1990, 184 cases of scorpion stings were recorded with an incidence rate of 38.6 cases per 10,000 inhabitants. The locality of San Fernando presented the highest incidence (68.3(0)/000) of poisonous accidents. The highest percentages of severe cases were recorded in the towns of Arenas (27%), San Lorenzo (21%), and Cocollar (19%), which are located at the foot of the Turimiquire Mountains. This region is a dispersion area of scorpions of the Tityus genus. Our results show that this region of the State of Sucre is endemic for scorpion stings which are an important public health problem.

Peptic disease and Helicobacter pylori are highly prevalent in patients with the indeterminate form of chagas’ disease: report of 21 cases

Given that chagasic patients in the indeterminate form of this disease, can have abnormal motility of the digestive tract and immunologic abnormalities, we decided to assess the frequency of peptic disease and Helicobacter pylori (Hp) infection in these individuals. Twenty-one individuals, 13 males and 8 females, mean age 37.6 ± 11.1 years, were examined. Biopsies of the duodenum, antrum, lesser and greater gastric curvature and esophagus were performed. The endoscopic findings were of chronic gastritis in 20 (95.2%) patients, duodenal ulcer in 3 (14.3%), gastric and duodenal ulcer in 3 (14.3%), gastric ulcer alone in 1 (4.8%), esophagitis in 5 (23.8%), and duodenitis in 5 (23.8%). The diagnosis of infection by the Hp was done by the urease test and histologic examination. Hp infection was found in 20 (95.2%) individuals: in 20 out of them in the antrum, in 17 in the lesser curvature, and in 17 in the greater curvature. Hp was not found in the esophagus and duodenum. The only individual with no evidence of infection by Hp was also the only one with normal endoscopic and histologic examinations. The histologic examinations confirmed the diagnoses of gastric ulcer as peptic, chronic gastritis in 20 patients, duodenitis in 14, and esophagitis in 9. In this series the patients had a high frequency of peptic disease, which was closely associated with Hp infection

EPIDEMIOLOGICAL SURVEY ON CANINE POPULATION WITH THE USE OF IMMUNOLEISH SKIN TEST IN ENDEMIC AREAS OF HUMAN AMERICAN CUTANEOUS LEISHMANIASIS IN THE STATE OF RIO DE JANEIRO, BRAZIL

A survey for canine tegumentary leishmaniasis (CTL) has been carried out between 1986 and 1993 in seven endemic localities for American cutaneous leishmaniasis in the State of Rio de Janeiro. 270 dogs have been examined for their clinical aspects, the development of delayed hypersensitivity (DHS) with Immunoleish antigen and with immunofluorescent antibody research of IgG (IF). 28.2% of them had ulcer lesions and 3.3% had scars. The lesions consisted of single (39.5%) and mucocutaneous lesions (31.6%), multiple cutaneous (25.0%) and mucocutaneous lesions associated with cutaneous ulcers (4.0%). Twelve (15.8%) isolates from biopsies were analyzed by zimodeme and schizodeme and identified as L. (V.) braziliensis. The overall prevalence of canine infection that was evaluated with the skin test was of 40.5% and with IF it was of 25.5%. Both tests showed a high positive rate with relation to the animals with mucosal lesions, as in the case of human mucocutaneous leishmaniasis. The comparison of the two tests showed the skin test to have a better performance although there was no statistical difference (p>0.05) between them. The proportional sensitivity and specificity was of 84.0% and 74.0%, respectively. The Immunoleish skin test and IF are useful tools to be employed in CTL field epidemiological surveys.

INFLUENCE OF MICROBIOTA IN EXPERIMENTAL CUTANEOUS LEISHMANIASIS IN SWISS MICE

Infection of Swiss/NIH mice with Leishmania major was compared with infection in isogenic resistant C57BL/6 and susceptible BALB/c mice. Swiss/NIH mice showed self-controlled lesions in the injected foot pad. The production of high levels of interferon-g (IFN-g) and low levels of interleukin-4 (IL-4) by cells from these animals suggests that they mount a Th1-type immune response. The importance of the indigenous microbiota on the development of murine leishmaniasis was investigated by infecting germfree Swiss/NIH in the hind footpad with L. major and conventionalizing after 3 weeks of infection. Lesions from conventionalized Swiss/NIH mice were significantly larger than conventional mice. Histopathological analysis of lesions from conventionalized animals showed abscesses of variable shapes and sizes and high numbers of parasitized macrophages. In the lesions from conventional mice, besides the absence of abscess formation, parasites were rarely observed. On the other hand, cells from conventional and conventionalized mice produced similar Th1-type response characterized by high levels of IFN-g and low levels of IL-4. In this study, we demonstrated that Swiss/NIH mice are resistant to L. major infection and that the absence of the normal microbiota at the beginning of infection significantly influenced the lesion size and the inflammatory response at the site of infection.

Jorge Lobo’s disease: experimental inoculation in Swiss mice

Sixty-four isogenic Swiss mice were intradermically inoculated in both hind foot pads. The inocula, consisting of fungal suspensions from biopsies obtained from Jorge Lobo’s Disease patients, had the total number of fungi and the viability index determined using a Neubauer chamber and the fluorescein diacetate-ethidium bromide technique (FD-EB), respectively. The animals were sacrificed at times ranging from ten days to eighteen months after inoculation. The cellular infiltrate, mainly consisting of macrophages containing fungi, increased progressively up to end of the study; however, no macroscopic alterations were observed in the inoculated feet. After nine months, small numbers of Langhans’ giant cells started to appear in the infiltrate. A considerable number of fungi was observed at the end of the experimental period, but only a few were viable when stained by the FD-EB technique. This fact suggests that there is a multiplication of fungal cells, which are destroyed by the macrophages but remain in the tissue for a long time due perhaps to the difficulties in their elimination. These findings led us to conclude that in spite of the maintenance of the infection in these animals, Swiss mice cannot be considered an ideal model to study Jorge Lobo’s Disease. However, the authors call attention to the possibility of other mouse strains being more susceptible to Paracoccidioides loboi.

Inoculation of BALB/c mice with Lacazia loboi

In a previous study, the authors inoculated Swiss mice with Lacazia loboi (L. loboi) and succeeded in maintaining a granulomatous infiltrate and viable fungal cells up to one year and six months after inoculation. Considering the experimental work on paracoccidioidomycosis, 0.03 ml of a fungal suspension obtained from a biopsy of a Jorge Lobo's Disease patient were inoculated into both hind foot pads of 32 six week-old BALB/c mice of both sexes. The animals were sacrificed 1, 4, 7 and 10 months post inoculation. The suspension contained 1.3 x 10(6) fungi/ml and presented 38% viability. Seven months after inoculation, most of the animals presented profuse infiltrates consisting of isolated histiocytes, foreign body and Langhans' giant cells and a large number of fungi, most of them viable. Emergence of macroscopic lesions was observed during the 8th month. Based on fungal count, viability index before and after inoculation, presence of macroscopic lesions and histopathological findings similar to the findings in humans, the authors believe that BALB/c mice may be a good experimental model to study Jorge Lobo's Disease, mainly regarding therapeutic evaluation.

Experimental dermatophytosis in hamsters inoculated with Trichophyton mentagrophytes in the cheek pouch

This study presents the results of T. mentagrophytes inoculation in the cheek pouch of the hamster, an immunologically privileged site. Forty two animals were used: 21 inoculated with 10(6) fungi in the cheek pouch (group 1) and 21 inoculated initially with 10(6) fungi in the foot pad and 15 days later in the cheek pouch, with the same amount of fungi (group 2). Animals were sacrificed at 20 hours, 3, 7, 14, 30, 60, and 120 days; samples from inoculated cheek pouch, and foot pads submitted to the foot pad test (FPT), were collected. Independent of group and time of evolution of infection, animals did not develop delayed hypersensitivity evaluated through the FPT. The pre-inoculation of fungi in the foot pad did not change the morphology of lesions induced in the cheek pouch. Therefore, in animals of group 1 and 2, the introduction of the fungus in the cheek pouch resulted in focal lesion composed of a sterile acute inflammatory infiltrate, with abscess formation that evolved to a macrophagic reaction, and later to resolution even in the absence of immune response detectable by FPT. Our results indicate that in spite of the important role of the immune response in the spontaneous regression of dermatophytosis, other factors are also an integral part in the defense against this fungal infection.

Confluent peripheral multiple mononeuropathy associated to acute hepatitis B: a case report

A thirty three year-old, male patient was admitted at the Hospital of the São Paulo University School of Medicine, at the city of São Paulo, Brazil, with complaint of pains, tingling and decreased sensibility in the right hand for the last four months. This had progressed to the left hand, left foot and right foot, in addition to a difficulty of flexing and stretching in the left foot. Tests were positive for HBeAg, IgM anti-HBc and HBsAg, thus characterizing the condition of acute hepatitis B. The ALT serum level was 15 times above the upper normal limit. Blood glucose, cerebral spinal fluid, antinuclear antibodies (ANA) and anti-HIV and anti-HCV serum tests were either normal or negative. Electroneuromyography disclosed severe peripheral neuropathy with an axon prevalence and signs of denervation; nerve biopsy disclosed intense vasculitis. The diagnosis of multiple confluent mononeuropathy associated to acute hepatitis B was done. This association is not often reported in international literature and its probable cause is the direct action of the hepatitis B virus on the nerves or a vasculitis of the vasa nervorum brought about by deposits of immune complexes.

Molecular and seroepidemiologic studies of Enterovirus 71 infection in the State of Pará, Brazil

In many countries, the Enterovirus 71 (EV-71) Picornaviridae family is associated to hand, foot and mouth disease in addition to acute neurological diseases while in Brazil these viruses are more closely associated to the latter group. The aim of this research was to use the first EV-71 isolate of the Northern region of Brazil in molecular and seroepidemiologic studies. Two (2.2%) out of 88 stool samples (44 cases of AFP), collected from January 1998 to December 2000 were positive for EV-71 isolation (73442/PA/99). Nucleotide sequence of the gen that codifies the VP1 protein showed that isolate 73442/PA/99 was similar to the EV-71 strains belonging to genotype B - more closely identified with EV-71 from North America. Neutralization test with 389 sera samples collected from January 1998 to November 2001, from individuals ranging from 0 to 15 years of age living in the city of Belém, State of Pará showed the following results in relation to isolate 73442/PA/99 and prototype BrCr: a total of 207 individuals (53.2%) had neutralization antibodies to both viruses, 167 (42.9%) had no antibodies and 15 showed the presence of neutralizing antibodies to one of the two viruses. Only 20.2% of the children aged 0 to 3 had neutralizing antibodies to EV-71, indicating that these children were more susceptible to the infection. Both the seroprevalence study and VP1 sequencing were important to demonstrate the spread and the molecular pattern of the EV-71 circulating in the Northern Region of Brazil.

The histopathology of cutaneous leishmaniasis due to Leishmania (Leishmania) mexicana in the Yucatan peninsula, Mexico

Localized Cutaneous Leishmaniasis (LCL) known as "chiclero's ulcer" in southeast Mexico, was described by SEIDELIN in 1912. Since then the sylvatic region of the Yucatan peninsula has been documented as an endemic focus of LCL. This study of 73 biopsies from parasitological confirmed lesions of LCL cases of Leishmania (Leishmania) mexicana infection was undertaken: 1) to examine host response at tissue level; and 2) to relate manifestations of this response to some characteristics of clinical presentation. Based on Magalhães' classification we found that the most common pattern in our LCL cases caused by L. (L.) mexicana was predominantly characterized by the presence of unorganized granuloma without necrosis, (43.8%). Another important finding to be highlighted is the fact that in 50/73 (68.5%) parasite identification was positive. There was direct relation between the size of the lesion and time of evolution (r s = 0.3079, p = 0.03), and inverse correlation between size of the lesion and abundance of amastigotes (r s = -0.2467, p = 0.03). In view of the complexity of clinical and histopathological findings, cell-mediated immune response of the disease related to clinical and histopathological features, as so genetic background should be studied.

Presence of Leishmania amastigotes in peritoneal fluid of a dog with leishmaniasis from Alagoas, Northeast Brazil

The goal of this short communication is to report the uncommon presence of intracellular amastigotes of Leishmania in peritoneal fluid of a dog with leishmaniasis from Alagoas State, Brazil. Physical examination of an adult male rottweiler suspected to be suffering of leishmaniasis revealed severe loss of weight, ascitis, splenomegaly, moderately enlarged lymph nodes, onychogryphosis, generalized alopecia, skin ulcers on the posterior limbs, and conjunctivitis. Samples of bone marrow, popliteal lymph node, skin ulcer, and peritoneal fluid were collected and smears of each sample were prepared and stained with hematoxylin and eosin. Numerous amastigotes were detected in bone marrow, popliteal lymph node, and skin ulcer smears. Smears of peritoneal fluid revealed the unusual presence of several free and intracellular amastigotes of Leishmania. Future studies are needed to determine whether the cytology of ascitic fluid represents a useful tool for diagnosis Leishmania infection in ascitic dogs, particularly in those living in areas where canine leishmaniasis is enzootic.

Cutaneous infection caused by Corynebacterium pseudodiphtheriticum: a microbiological report

We report here a rare case of cutaneous infection due to Corynebacterium pseudodiphtheriticum. The patient presented to the clinical laboratory with a skin ulcer on his left leg. Gram-stained preparation of the purulent secretion revealed the presence of numerous rod-shaped Gram-positive organisms in the absence of any other species. The organism was grown in pure culture on sheep blood agar and was further identified as C. pseudodiphtheriticum using a commercial identification system (API-Coryne, BioMérieux, France). The infection was successfully treated with ciprofloxacin. This case emphasizes the importance of the clinical microbiology laboratory in correctly identifying Gram-positive organisms obtained in pure culture from skin ulcers.

RESOLUTION OF CUTANEOUS LEISHMANIASIS AFTER ACUTE ECZEMA DUE TO INTRALESIONAL MEGLUMINE ANTIMONIATE

We report a case of a 42 year-old female, who came to a leishmaniasis reference center in Rio de Janeiro, Brazil, presenting a cutaneous leishmaniasis lesion in the right forearm. Treatment with low-dose intramuscular meglumine antimoniate (MA) (5 mg Sb5+/kg/day) was initiated, with improvement after 28 days, although with the development of generalized eczema. After 87 days, the lesion worsened. Patient refused treatment with amphotericin B. MA was then infiltrated in the lesion, in two sessions, resulting in local eczema, with bullae formation; however, twenty days after, both the ulcer and eczema receded. Intralesional administration of MA should be used carefully when previous cutaneous hypersensitivity is detected.

Mycetoma fungal infection: multiple organisms as colonizers or pathogens?

We describe a patient with mycetoma or Madura foot, in which histopathological stains of the bone and surface cultures suggested three different organisms including Nocardia species as the cause. Criteria for the diagnosis of the organisms, differentiation between colonizer and pathogen, and significance of mixed infections are discussed.