Molecular epidemiology of Cryptosporidium spp. in an agricultural area of northern Vietnam: A community survey

The purpose of this study was to investigate the occurrence of Cryptosporidium infection and the potential for transmission of Cryptosporidium spp. between animals and humans in northern Vietnam. A total of 2715 samples (2120 human diarrheal samples, 471 human non-diarrheal samples, and 124 animal stool samples) were collected through our community survey in an agricultural area. All samples were tested for Cryptosporidium spp. by direct immunofluorescence assay (DFA) using a fluorescent microscope. DNA extraction, PCR amplification of three genes (COWP, SSU-rRNA, and GP60), and sequencing analysis were performed to identify Cryptosporidium spp. Of 2715 samples, 15 samples (10 diarrheal samples, 2 non-diarrheal samples, and 3 animal stool samples) tested positive by PCR for the COWP gene. Three species of Cryptosporidium spp. were identified as C. canis (from six human diarrheal samples, two human non-diarrheal samples, and one dog sample), C. hominis (from four human diarrheal samples), and C. suis (from two pig samples) by sequencing the amplified COWP and/or SSU-rRNA genes. In terms of C. hominis, the GP60 subtype IeA12G3T3 was detected in all four human diarrheal samples. Although the number of positive samples was very small, our epidemiological data showed that the emerging pattern of each of the three species (C. canis, C. hominis, and C. suis) was different at this study site. While C. hominis and C. suis were only detected in human and pig samples, respectively, C. canis was detected in samples from both dogs and humans. We suspect that C. canis infections in humans at this study site may be due to environmental contamination with animal and human feces.

Molecular epidemiology of Giardia spp. in northern Vietnam: Potential transmission between animals and humans

Giardia spp. is detected frequently in humans and animals. Although many studies have been conducted on the epidemiology of giardiasis, there is a scarcity of information on the genetic diversity and the dynamics of transmission of Giardia spp. in Vietnam. The zoonotic potential of Giardia spp. remains elusive. The objective of this study was to determine the genetic diversity of Giardia spp. in both humans and livestock to assess the existence of a route of infection between livestock and humans. Our goal was to assess the role animals play in the epidemiology of human infection in northern Vietnam. In Hien Khanh commune in northern Vietnam, 311 households with 1508 residents were randomly selected for a diarrheal cohort study. Of these, 2120 human diarrheal samples were collected from 1508 residents in 2014 and 2017. Of these, non-diarrheal samples were cross-sectionally collected from 471 residents. At the same site, livestock samples from buffalo, dairy and beef cattle, pigs, and dogs were collected. All stool samples were examined for Giardia spp. by Direct Immunofluorescence Assay (DFA) using fluorescent microscope. DNA extraction, PCR analysis of the 3 genes (bg, gdh, tpi), and sequencing analysis were continuously carried out. A total of 23 animal stool samples, 8 human non-diarrheal samples, and 36 human diarrheal samples were Giardia spp. were positive by PCR using the bg and gdh genes. Giardia spp. assemblage AII and E were detected in both animal samples and human samples in this study site. The detection of assemblage E in human stool samples suggests the first human case report in Vietnam. We assume that the unexpected human infection of all Giardia assemblages including A, B, and E may be due to an environment contaminated with animal and human feces in this village.

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Giardia spp. assemblage A and E have been detected in buffalo, cattle and pigs, as well as in humans, while assemblage B appeared only in humans.

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This was the first report of assemblage E in humans in Vietnam.

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Zoonotic transmission of assemblage AII and E could not be excluded in our study site.

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In addition to the ‘animal-to-human’ route, there potentially might be transmission routes from ‘humans-to-humans’ and/or ‘humans-to-animals’ in this study site.

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The novel genotype belonging to assemblage AIII has been isolated only in buffalo.

Cross-sectional studies of tuberculosis prevalence in Cambodia between 2002 and 2011

OBJECTIVE

To measure trends in the pulmonary tuberculosis burden between 2002 and 2011 and to assess the impact of the DOTS (directly observed treatment, short-course) strategy in Cambodia.

METHODS

Cambodia's first population-based nationwide tuberculosis survey, based on multistage cluster sampling, was conducted in 2002. The second tuberculosis survey, encompassing 62 clusters, followed in 2011. Participants aged 15 years or older were screened for active pulmonary tuberculosis with chest radiography and/or for tuberculosis symptoms. For diagnostic confirmation, sputum smear and culture were conducted on those whose screening results were positive.

FINDINGS

Of the 40,423 eligible subjects, 37,417 (92.6%) participated in the survey; 103 smear-positive cases and 211 smear-negative, culture-positive cases were identified. The weighted prevalences of smear-positive tuberculosis and bacteriologically-positive tuberculosis were 271 (95% confidence interval, CI: 212-348) and 831 (95% CI: 707-977) per 100,000 population, respectively. Tuberculosis prevalence was higher in men than women and increased with age. A 38% decline in smear-positive tuberculosis (P = 0.0085) was observed with respect to the 2002 survey, after participants were matched by demographic and geographical characteristics. The prevalence of symptomatic, smear-positive tuberculosis decreased by 56% (P = 0.001), whereas the prevalence of asymptomatic, smear-positive tuberculosis decreased by only 7% (P = 0.7249).

CONCLUSION

The tuberculosis burden in Cambodia has declined significantly, most probably because of the decentralization of DOTS to health centres. To further reduce the tuberculosis burden in Cambodia, tuberculosis control should be strengthened and should focus on identifying cases without symptoms and in the middle-aged and elderly population.

Optimization of the microscopic observation drug susceptibility assay for four first-line drugs using Mycobacterium tuberculosis reference strains and clinical isolates

OBJECTIVE

The aim of this study is to determine the appropriate cut-off value and turnaround time of the microscopic observation drug susceptibility assay (MODS) for isoniazid (INH), rifampicin (RMP), streptomycin (STR), and ethambutol (EMB).

DESIGN

A total of 39 Mycobacterium tuberculosis strains with confirmed drug susceptibility (reference strains) were tested with a range of drug concentrations to determine the optimal cut-off values for INH, RMP, STR, and EMB by MODS. Standard drug susceptibility testing (DST) results were evaluated relative to the Löwenstein-Jensen (L-J) proportion method. Following which, the performance of MODS was evaluated again using 36 sputum samples from patients with tuberculosis (TB) using the cut-off values determined in the aforementioned process.

RESULTS

With 39 reference strains, DST identified the following cut-off values: 0.8μg/ml INH (sensitivity, 96.0%; specificity, 92.9%), 2.0μg/ml RMP (sensitivity, 100%; specificity, 95.5%), 4.0μg/ml STR (sensitivity, 90.5%; specificity, 93.8%), and 4.0μg/ml EMB (sensitivity, 100%; specificity, 91.7%). When these cut-off values were used to analyze the 36 clinical isolates, the sensitivity and specificity of MODS were 100% and 93.1% for INH, 100% and 93.8% for RMP, 87.5% and 96.4% for STR, and 100% and 88.2% for EMB, respectively. The turnaround time for these clinical specimens was 9.0days by MODS (95% CI: 5.3-12.7), compared with 11.7days (95% CI: 9.5-13.9) for smear negative specimens.

CONCLUSION

Our study identified the optimal cut-off values of the four first-line drugs for MODS based on a wide concentration range. With the optimal cut-off values determined in this study, MODS showed high discriminatory efficiency for DST. This study also demonstrated that MODS is useful for rapid diagnosis of drug-resistant TB even for a smear negative specimen, despite the fact that it generally uses smear positive specimens as direct DST.

Comparative evaluation of three immunochromatographic identification tests for culture confirmation of Mycobacterium tuberculosis complex

BACKGROUND

The rapid identification of acid-fast bacilli recovered from patient specimens as Mycobacterium tuberculosis complex (MTC) is critically important for accurate diagnosis and treatment. A thin-layer immunochromatographic (TLC) assay using anti-MPB64 or anti-MPT64 monoclonal antibodies was developed to discriminate between MTC and non-tuberculosis mycobacteria (NTM). Capilia TB-Neo, which is the improved version of Capilia TB, is recently developed and needs to be evaluated.

METHODS

Capilia TB-Neo was evaluated by using reference strains including 96 Mycobacterium species (4 MTC and 92 NTM) and 3 other bacterial genera, and clinical isolates (500 MTC and 90 NTM isolates). M. tuberculosis isolates tested negative by Capilia TB-Neo were sequenced for mpt64 gene.

RESULTS

Capilia TB-Neo showed 100% agreement to a subset of reference strains. Non-specific reaction to M. marinum was not observed. The sensitivity and specificity of Capilia TB-Neo to the clinical isolates were 99.4% (99.6% for M. tuberculosis, excluding M. bovis BCG) for clinical MTC isolates and 100% for NTM isolates tested, respectively. Two M. tuberculosis isolates tested negative by Capilia TB-Neo: one harbored a 63-bp deletion in the mpt64 gene and the other possessed a 3,659-bp deletion from Rv1977 to Rv1981c, a region including the entire mpt64 gene.

CONCLUSIONS

Capilia TB-Neo is a simple, rapid and highly sensitive test for identifying MTC, and showed better specificity than Capilia TB. However, Capilia TB-Neo still showed false-negative results with mpt64 mutations. The limitation should be recognized for clinical use.

[Evaluation of GenoType MTBDRplus for the detection of multi-drug-resistant Mycobacterium tuberculosis strains]

OBJECTIVE

To evaluate GenoType MTBDRplus (Hain Lifescience, Germany) for its capacity to detect the resistance of rifampicin (RFP) and isoniazid (INH).

METHOD

A total of 44 confirmed multi-drug resistant (MDR) and 67 susceptible M. tuberculosis strains were tested for susceptibility to RFP and INH by GenoType MTBDR plus. The core 81bp region of the rpoB gene and the 322bp region of the katG gene and the inhA gene (248bp of which included the promoter and the ORF of the 379bp inhA) were directly sequenced for both MDR-TB and susceptible M. tuberculosis strains, and the mutations were confirmed. Susceptibility was tested by standard proportion method with 1% Ogawa medium.

RESULTS

The sensitivities of GenoType MTBDRplus for RFP and INH resistance were 97.7% and 65.9%, respectively. The specificity for RFP and INH was 100%. The sensitivity of GenoType MTBDRplus was almost equivalent to the sequencing method for RFP, but that for INH was slightly inferior to the sequencing without significant difference. Geno Type MTBDRplus detected 97.7% of the mutations of rpoB compared with the direct sequencing. It also detected 24 katG MUT1 (S315T1) (54.5%) and 5 inhA MUT1 (C15T) mutations (11.4%), while the direct sequencing detected an additional 2 (4.5%) katG mutants.

DISCUSSION

The accuracy of GenoType MTBDRplus for the detection of RFP resistance was confirmed to be comparable to that of DST using conventional culture-based methods, while it was less accurate for detection of INH resistance. GenoType MTBDRplus is useful for early diagnosis and infection control for MDR-TB because it has a short turnaround time of approximately 6 hours.

The expression of basic fibroblast growth factor and vascular endothelial growth factor in prostatic adenocarcinoma: correlation with neovascularization

BACKGROUND

Neovascularization associated with tumor invasion and metastasis may be stimulated by factors which are released from tumor cells, tumor-associated inflammatory cells or extracellular matrix. Although basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) have been characterized as promoters of angiogenesis, their precise localization in prostatic adenocarcinoma remains unclear.

MATERIALS AND METHODS

In this study, the immunohistochemical expression of the growth factors and their receptors were studied using paraffin-embedded archival tissues before and after neoadjuvant hormonal therapy. The mRNA expression of the growth factors was also examined using an in situ hybridization (ISH) technique.

RESULTS

The ISH study demonstrated that bFGF mRNA was present only in the stromal cells whilst that VEGF mRNA was present only in the adenocarcinoma cells. In contrast, the immunohistochemical study showed that bFGF, FGF receptor, VEGF and VEGF receptor proteins were expressed in adenocarcinoma cells and in endothelial cells. We also observed that microvessel density in prostatic adenocarcinoma was correlated with the degree of the expression of growth factors in the cases without neoadjuvant hormonal therapy. Additionally, the expression of those receptor proteins were much frequently identified in the cases with neoadjuvant hormonal therapy than those without it, while virtually no change in the expression of ligands was observed between the cases without and with neoadjuvant therapies.

CONCLUSIONS

In prostatic adenocarcinoma, bFGF and VEGF may correlate with neovascularization through each characteristic pathway. In addition, we assumed that neoadjuvant hormonal therapy may have minimal inhibitory effects on bFGF, VEGF and their receptors.

Expression of platelet-derived endothelial cell growth factor in prostatic adenocarcinoma

Angiogenesis is thought to play critical roles in local tumor growth and eventual metastasis. No studies have examined the expression of platelet-derived endothelial cell growth factor (PD-ECGF) in prostatic tissues. Prostatic tissues were obtained from 36 prostatic adenocarcinoma patients. We assessed the expression of PD-ECGF using ELISA and immunohistochemistry. The mean level of PD-ECGF in prostatic adenocarcinomas was higher than that in neighboring normal prostatic tissues in ELISA. Immunohistochemistry showed that the expressions of PD-ECGF, which were associated with increase of microvessel count, were found in the endothelial cells, macrophages, lymphocytes, or fibroblasts. These results suggest that PD-ECGF is involved in the development of prostatic adenocarcinoma.

[Obesity as one of the risk factors for urolithiasis]

BACKGROUND

It is well known that many diseases may be associated with obesity resulting from an energy-rich diet, and that a westernized diet may increase the incidence of urinary stone formation. To evaluate degree of obesity, we investigated body mass index (BMI) in patients with calcium containing upper urinary stones and examined their blood with regard to lipid metabolism.

METHODS

Between July 1994 and December 1995, we analyzed 332 fresh renal-stone formers (253 males and 79 females) who visited 7 hospitals located in Ehime prefecture. As a control, 949 residents older than 20 years (387 males and 562 females) of the same prefecture were also examined by the annual Ehime prefecture office report of 1994. Body mass index as degree of obesity, stone-recurrence, blood test and other complicated diseases were examined.

RESULTS

In male stone formers the rate of obesity was significantly higher than that of control males (p < 0.001). The differences were seen only in their twenties and fifties. Furthermore, among male stone formers the rate of obesity was significantly higher in recurrent stone formers than in single stone formers (p < 0.05). On the other hand, in female, there was no significant difference in the rate of obesity between stone formers and controls. No difference was seen between recurrent stone formers and single stone formers. In the blood test, there was no differences in the level of calcium, phosphate and uric acid between stone formers and controls. The level of cholesterol and triglyceride in male were significantly higher in controls (p < 0.01) and there was no difference in the level of high density lipoprotein (HDL) between stone formers and controls. Among the stone formers, 48 males (20.0%) and 17 females (21.5%) had other diseases. The rate of complicated diseases was similar to that of controls and no specific diseases in the stone formers were identified.

CONCLUSION

Our report suggested that obesity in male should be considered as a risk factor for calcium containing stone formation.

Apoptosis in prostatic adenocarcinomas; a study of relationship to Ki-67 and Bcl-2 protein expression

BACKGROUND

Tissue samples from patients with prostatic adenocarcinoma (PCA) were examined for relationship between apoptosis and expression of Ki-67 and bcl-2 protein.

MATERIALS AND METHODS

Prostatic tissue was obtained from 29 prostatic cancer patients with no prior therapy. The number of apoptotic cells (apoptotic index; AI) and the percentage of Ki-67 stained cells (Ki-67 labeling index; LI) were compared with the expression of bcl-2 which was evaluated by the proportion and intensity of tumor cell immunostaining.

RESULTS

Both AI and LI of moderately and poorly differentiated PCAs were significantly higher than those of well differentiated PCAs. There was a significant correlation between AI and LI. Bcl-2 protein was expressed less in moderately and poorly differentiated PCAs than in well differentiated PCAs. Moreover, there was no correlation between the bcl-2 protein expression and the AI.

CONCLUSIONS

The results suggest that, in PCAs, the degree of apoptosis is correlated with the cellular proliferation, and that expression of bcl-2 protein is not a critical factor that determines the degree of apoptosis.

Cholesteatoma of the ureter: a case report

A 72-year-old man complained of general fatigue and had low grade fever. Ultrasonography, excretory urography, retrograde urography, and computed tomography revealed left hydronephrosis due to a middle ureteral tumor. A nephroureterectomy was performed. The histological diagnosis was hyperkeratosis with a cholesteatoma.

[Cardiac herniation after right sleeve pneumonectomy with partial pericardiectomy]

A 63-year-old male underwent a sleeve pneumonectomy with partial pericardiectomy for a squamous cell carcinoma of the right upper bronchus invading the trachea. The pericardial defect was closed primarily. The initial postoperative course was uneventful until we performed endotracheal suction with bronchoscopy in that evening. After severe coughing, he was noted to have a decrease in blood pressure following bradycardia and premature ventricular contraction. He soon fell in shock. A chest X-ray film revealed the cardiac shadow shifted to the right hemithorax. Immediately he was taken back to the theater and rethoracotomy was performed. The heart was found to have herniated into the right hemithorax. As soon as it was repositioned, his general condition improved. The pericardial defect was repaired with a GORE-TEX patch. He recovered. The cardiac herniation after pneumonectomy is one of the fatal complications unless prompt diagnosis and surgical reduction should be done. Repair of the pericardial defect with strong prosthetic patches and careful postoperative management are indispensable for the prevention of the cardiac herniation after pneumonectomy.