Mycetoma in Ecuador

BACKGROUND

Previous studies on the distribution of mycetoma globally have failed to identify Ecuador as an endemic country.

METHODS

We present data on 35 cases of mycetoma in Ecuador between 1955 and 2021: 5 cases from our experience and 30 cases from the literature.

RESULTS

Eight cases of eumycetoma (23%) and 27 cases of actinomycetoma (77%) were diagnosed. Most cases originated from the coastal region of Ecuador.

CONCLUSIONS

For the first time in an English-language publication, this communication confirms the presence of mycetoma in Ecuador, securing Ecuador's position on the global mycetoma map.

Successful treatment of mucosal neuromas by radiofrequency ablation in a patient with multiple endocrine neoplasia type 2B

This is the first report of mucosal neuromas being treated successfully with radiofrequency ablation in a patient with multiple endocrine neoplasia type 2B.

Nasal cartilage destruction associated to cutaneous histoplasmosis in AIDS

Background

Systemic histoplasmosis is a disease of high morbidity and mortality in immunocompromised patients. Patients with AIDS get the infection through inhalation of spores, triggering a primary lung infection with a subsequent hematogenous spread to multiple organs, including the skin. Tissue necrosis have been documented in cutaneous histoplasmosis with multiple clinical manifestations that mimic other diseases.

Case presentation

We report the case of nasal cartilage destruction associated to cutaneous histoplasmosis in AIDS. A 24-year-old man, resident in Ecuadorian coast, with a history of HIV for 7 years without any treatment. In the last 3 months, he has been presenting a molluscum-like lesions on his nasal bridge with subsequent dissemination to the trunk and extremities. He was admitted to the emergency department for dyspnoea, cough, and malaise. Due to his respiratory failure, he was admitted to the intensive care unit (ICU) with mechanical ventilation. Physical examination reveals a crusted surface ulcer that involves the nose and cheeks, associated with erythematous papules, some with a crusted surface which are spread to the face, trunk, and upper limbs. The patient has a specific skin involvement with a butterfly-like ulcer appearance and destruction of the upper and lower lateral cartilage of the nose. At admission CD4 cell count was 11/mm3 with a HIV viral load of 322,908 copies. Mycological cultures identified Histoplasma capsulatum. A treatment with highly active antiretroviral therapy (HAART) was stablished, associated with liposomal amphotericin B at a dose of 3 mg/kg/day and itraconazole 200 mg twice a day for 12 months.

Conclusions

Cutaneous histoplasmosis is a rare manifestation of pulmonary histoplasmosis in patients with AIDS. The cutaneous manifestations included papules, nodules, plaques, and ulcers. A histology examination is required to rule out other fungal or parasitic infections. Treatment includes highly active antiretroviral therapy (HAART), amphotericin B liposomal and itraconazole, the latest for at least 12 months.

Seroprevalence and risk factors for Trypanosoma cruzi infection in the Amazon region of Ecuador

Trypanosoma cruzi infection in the Ecuadorian Amazon region has recently been reported. A seroepidemiologic survey conducted in four provinces in this region indicates a seroprevalence rate of 2.4% among the 6,866 samples collected in 162 communities. Among children < OR = 10 years of age, 1.2% were seropositive. Risk factors for T. cruzi seropositivity were having been born and remaining in the Ecuadorian Amazon provinces, age, living in a house with a thatch roof and open or mixed wall construction, recognizing the vector insects, and reporting being bitten by a triatomine bug. These data suggest active transmission of Chagas' disease in the Ecuadorian Amazon region is associated with poor housing conditions, and highlight the need for further studies aimed at understanding the biology of the insect vectors, reservoir species, and the clinical impact of T. cruzi infection as the basis for future educational and control programs in this region.

Phylogenetic analysis of Cryptosporidium parasites based on the small-subunit rRNA gene locus

Biological data support the hypothesis that there are multiple species in the genus Cryptosporidium, but a recent analysis of the available genetic data suggested that there is insufficient evidence for species differentiation. In order to resolve the controversy in the taxonomy of this parasite genus, we characterized the small-subunit rRNA genes of Cryptosporidium parvum, Cryptosporidium baileyi, Cryptosporidium muris, and Cryptosporidium serpentis and performed a phylogenetic analysis of the genus Cryptosporidium. Our study revealed that the genus Cryptosporidium contains the phylogenetically distinct species C. parvum, C. muris, C. baileyi, and C. serpentis, which is consistent with the biological characteristics and host specificity data. The Cryptosporidium species formed two clades, with C. parvum and C. baileyi belonging to one clade and C. muris and C. serpentis belonging to the other clade. Within C. parvum, human genotype isolates and guinea pig isolates (known as Cryptosporidium wrairi) each differed from bovine genotype isolates by the nucleotide sequence in four regions. A C. muris isolate from cattle was also different from parasites isolated from a rock hyrax and a Bactrian camel. Minor differences were also detected between C. serpentis isolates from snakes and lizards. Based on the genetic information, a species- and strain-specific PCR-restriction fragment length polymorphism diagnostic tool was developed.

Differentiating human from animal isolates of Cryptosporidium parvum

We analyzed 92 Cryptosporidium parvum isolates from humans and animals by a polymerase chain reaction/restriction fragment length polymorphism method based on the thrombospondin-related anonymous protein 2 gene sequence. Used as a molecular marker, this method can differentiate between the two genotypes of C. parvum and elucidate the transmission of infection to humans.

Short report: screening for Trypanosoma cruzi in the blood supply by the Red Cross blood bank in Quito, Ecuador

The status of Chagas' disease in Ecuador is not clear. In response to reports suggesting the possibility of transfusion-associated transmission of Chagas' disease in the blood bank in Quito, the Ecuadorian Red Cross in collaboration with the Instituto Nacional de Higiene, Zona Norte and the Tropical Disease Institute of Ohio University implemented a pilot Chagas' disease screening of the donated blood in the Quito blood bank. The results of the screening showed a low incidence of seropositivity among the donors (0.01% in 1994, 0.04% in 1995, and 0.02% in 1996) to the Quito blood bank and a higher seropositivity in samples donated to smaller blood banks (0.4% in 1994, 0.28% in 1995, and 0.13% in 1996) located in areas considered endemic, as well as from at least two areas previously considered nonendemic for Chagas' disease. This report highlights the need for a comprehensive evaluation of the prevalence and distribution of Chagas' disease in Ecuador.

Prevalence of anti-Taenia solium antibodies in sera from outpatients in an Andean region of Ecuador

Sera from 9,254 individuals that presented at one of three outpatient clinics in Quito, Ecuador were assayed by indirect hemagglutination for the presence of antibodies reactive with antigens from Taenia solium cysts. Immunoblot analysis of 81 selected sera with IHA titers ranging from 0 to 1,028 showed that a titer of > or = 32 was suggestive of exposure to the parasite. Nine percent (9%) of the 9,254 patients had titers of 32 or greater. Of 3,503 sera from one clinic, which included sera from food handlers undergoing yearly physicals, 390 (11%) were positive. In addition, a correlation with age was seen in some, but not all, populations. In situations where age-related effects were noted, the highest incidence was seen in the youngest (0-20 years) and in the oldest (51-60 years) group. Thus, a resurgence of infection after a period of lower prevalence may be developing. Overall, this study shows that cysticercosis is relatively common and potentially a serious health problem in this region.

Gentamicin formation in Micromonospora purpurea: stimulatory effect of ammonium

The effect of ammonium on the fermentative production of gentamicin in Micromonospora purpurea has been studied using a chemically defined medium. Ammonium chloride concentrations ranging from 20 to 150 mM resulted in a proportional stimulation of growth and antibiotic formation. The use of other ammonium salts exerted a similar effect. Among the products of ammonium assimilation, glutamate and glutamine were able to exert the stimulatory effect. In addition, both amino acids reproduced the stimulation in resting cell systems of this microorganism and this result was not modified by the presence of chloramphenicol, eliminating a possible inductive action as the cause of this effect. The use of a glutamine synthetase inhibitor prevented antibiotic formation. This inhibition was reverted only by glutamine, suggesting that this amino acid was responsible of ammonium stimulation. Glutamine stimulation seems to be due to its ability to produce 2-deoxystreptamine and glucosamine, intermediates of the gentamicin biosynthetic pathway.

Blood donors in a vector-free zone of Ecuador potentially infected with Trypanosoma cruzi

Chagas' disease is a serious health problem for the population of South and Central America. Blood transfusion is the second most common way in which this disease is transmitted. Several studies have reported finding Trypanosoma cruzi-infected blood in blood banks in endemic areas. Serum samples were taken from the Red Cross blood bank in Quito, a nonendemic and vector free zone of Ecuador, in December 1992 and May 1993 and analyzed by enzyme-linked immunosorbent assay using crude epimastigote extract from the Brazil strain of T. cruzi. Of 162 samples examined in December 1992, 12.1%, 13.9%, and 74% were seropositive, indeterminate, and seronegative, respectively. Of 173 samples taken in May 1993, 6.2%, 17.9%, 75.9% were seropositive, indeterminate, and seronegative, respectively. Western blot analysis of these sera using sodium dodecyl sulfate-polyacrylamide gel electrophoresis with 7.5% gels separated T. cruzi epimastigote antigen proteins, and revealed a reaction with a 205-kD doublet antigen with most of the seropositive samples. These results indicate the necessity for long-term screening of blood bank donors to reduce the risk of transfusion transmission of the disease even in areas of endemic countries where the vector is not present.

Physiological studies on gentamicin: phosphate repression of antibiotic formation

The effect of inorganic phosphate on the fermentative production of gentamicin by Micromonospora purpurea has been studied using a chemically defined medium. Phosphate concentrations higher than 5.75 mM (1 g/liter-1) did not inhibit growth but specifically prevented antibiotic formation. Changes in the pH medium and carbon or nitrogen depletion were excluded as the cause of antibiotic underproduction. The use of a phosphate analogue, a protein synthesis inhibitor and the profiles of differential rate of antibiotic production suggested that phosphate itself transiently repressed gentamicin formation. Phosphate affected the formation of 2-deoxystreptamine from 2-deoxyinosose, a none phosphorylated substrate.

Carbon catabolite regulation of gentamicin formation

The effect of utilizable carbon sources on the production of gentamicin by Micromonospora purpurea has been studied. High D-glucose and D-xylose concentrations (40 mg/ml), exerted a strong and permanent negative action on antibiotic formation. On the other hand, similar concentrations of D-fructose, D-mannose, maltose and starch caused no effect. The glucose action is seen only if added during the logarithmic growth phase; moreover, the sugar needs to be metabolized to show its negative effect.

Tuberculous meningitis. Short course of chemotherapy

In March 1986, we began a 6-month short course trial of therapy for tuberculous meningitis, in which 28 patients were analyzed. The diagnosis was based on the following cerebrospinal fluid test results: in 53.5% of the cases, Mycobacterium tuberculosis was identified by direct smear; in 57%, culture in Löwenstein-Jensen medium was positive; in 83.3%, the detection of anti-bacille Calmette-Guérin (BCG) antibodies by enzyme-linked immunosorbent assay was positive; and in 74%, the dosification of adenosine deaminase activity was positive. In addition, in 21.4% of the cases, the diagnosis was established by means of autopsy findings. Moreover, the diagnosis was supported by bacteriological analyses from another tissue or body fluids. Despite the administration of an antituberculous therapy, 32.4% of the patients died: all of the decreased had reached the last stage of the disease by the beginning of treatment. Sixteen percent of the patients who survived after more than 18 months of follow-up after therapy had ended suffered neurological sequelae. With the 6-month therapeutic regimen, the morbidity/mortality is similar to that found in the longer-course therapies. The latter regimen is therefore thought to be a good and acceptable therapeutic option for the treatment of tuberculous meningitis.

Neurocysticercosis. Short course of treatment with albendazole

Eighteen patients with nonenhancing parenchymal brain cysts were treated with albendazole; 9 patients were treated for 3 days and 9 patients for 1 month at daily doses of 15 mg/kg of body weight. Three months after starting therapy, results showed that in both groups the treatment was highly effective. Control studies carried out in the same group before the trial did not show any significant improvement. Five patients were controls and were treated only with symptomatic drugs. The total diameter of the lesions was reduced from 220.1 mm to 52.1 mm, which signifies a reduction of 76.3% in patients treated for a period of 3 days, and from 278.5 mm to 82.1 mm, which is 70.5%, in patients treated for 30 days. We conclude that albendazole administered according to the 3-day therapeutic scheme proposed above is as highly effective for the treatment of parenchymal brain cysticercosis as the 30-day scheme.

Glutathione formation in Penicillium chrysogenum: stimulatory effect of ammonium

Penicillium chrysogenum produced glutathione after growth in a defined medium containing 10 mM-NH4Cl as the sole source of nitrogen. The use of higher ammonium concentrations (100 mM) resulted in stimulation of growth and glutathione formation. In addition, increases in the intracellular pools of glutamate, alanine and glutamine, proportional to the amount of ammonium present in the medium were observed. Resting cell systems, prepared from cells previously grown with ammonium, were able to produce glutathione when incubated with ammonium or the amino acids glutamate, alanine and glutamine. A mutant lacking NADP-dependent glutamate dehydrogenase activity (which has a leaky phenotype on ammonium as sole nitrogen source) required glutamate to synthesize glutathione. Resting cell systems of this mutant, prepared from cells previously grown with ammonium, did not produce glutathione even when incubated with glutamate or glutamine. On the other hand, resting cell systems of this mutant produced glutathione if prepared from cells previously grown with glutamate. The addition of glutamate to resting cell systems of the wild-type strain stimulated the synthesis of gamma-glutamylcysteine synthetase, the first enzyme of glutathione biosynthesis.

Transient repression of erythromycin formation in Streptomyces erythraeus

The effect of a D-glucose on growth and erythromycin production by Streptomyces erythraeus was investigated. D-Glucose stimulated growth and caused a strong but temporary suppression of antibiotic formation. Maximum specific suppression of erythromycin formation occurred at a carbohydrate concentration of 20 mg ml-1. A non-metabolizable analogue of glucose, 2-deoxy-D-glucose, also suppressed antibiotic formation. Since glucose caused a decrease in erythromycin formation only when added before the stage of antibiotic production, we conclude that this sugar exerted a transient repressive effect on erythromycin biosynthesis.

Characterization of a site-specific restriction endonuclease SphI from Streptomyces phaeochromogenes

A new type-II restriction endonuclease SphI, has been partially purified from Streptomyces phaeochromogenes. SphI recognizes the hexanucleotide sequence 5'-GCATGC and cleaves it at the position marked by the arrow. This nucleotide sequence is present twice in SV40 DNA, four times lambda DNA and only once in the cloning vehicles pBR322, pBR325, pBR327 and pBR328.