Deaminase Test Research Articles

Characterization and biocontrol potential of some rhizobacteria against fungal pathogens causing foliar diseases in maize

Maize is one of the most consumed cereal crops worldwide, and it is a strategic crop to the attainment of SDG 2 of Zero hunger. Despite its importance, the cultivation of maize has been significantly impaired by fungal pathogens causing foliar diseases. The occurrence of this disease in maize plantations at the Research Farm of the North-West University, Molelwane, Mafikeng, South Africa prompted this investigation. Samples of diseased maize rhizosphere soil were aseptically collected. Bacteria species associated with the rhizosphere were isolated and characterized as Bacillus siamensis, Enterobacter asburiae, Enterobacter chengduensis, Priestia aryabhattai, Burkholderia sp., Priestia megaterium strain AOA6 and Priestia megaterium strain AOA7. The anti-fungicidal potentials of the bacterial species were evaluated against pathogenic fungal species, Nigrospora sphaerica, Alternaria alternata and Fusarium equiseti in-vitro. The percentage mycelia growths were calculated and the data were subjected to ANOVA using SAS version 9.8. All the seven bacteria isolates tested positive to ammonia production, phosphate solubilization, siderophore production and ACC deaminase tests. The percentage mycelia inhibition showed Nigrospora sphaerica (36.29%), A. alternata (26.19%) and F. equiseti (20.63%) as the order of fungal inhibition by the bacteria species. Furthermore, E. asburiae > P. megatarium strain AOA7 > B. siamensis > P. aryabhattai > E. chengduensis > Bulkholderia sp. were the order of antifungal efficacy of the bacteria species evaluated. In conclusion, the efficacy of the bacteria especially E. asburiae, P. megatarium strain AOA7 and B. siamensis over various fungal pathogens. The result obtained, therefore, justifies the further investigation, formulation and deployment of the bacteria species as biofungicide in the management of foliar diseases of maize. Keywords: antifungicidal potential, biofungicide, microbial formulations, rhizosphere, zero hunger.

Isolation and Diagnosis of the Bacterium Pectobacterium Caratovorium, the Causative Agent of Soft Rot Disease on Potatoes, Macroscopically and Biochemically

This study aimed to isolate the bacterium Pectobacterium sp., the causal agent of soft rot disease on potato tubers, and to test its pathogenicity on potato tuber slices. It was also aimed to diagnose it macroscopically and biochemically to the species level. The isolation results showed that 40 bacterial isolates were obtained from potato stems, tubers, and soils collected from potato cultivation fields and storage facilities for the 2021 agricultural season from the areas of Yusufiyah, Radwaniyah, Abu Ghraib, Taji, Madaen, and Alwa Jamila. The results of the pathogenicity test for 40 isolates on potato slices showed that they had different pathogenicity in damaging potato slices, with three isolates (Pc1, Pc4, and Pc11) significantly outperforming the remaining isolates and the control treatment. The three isolates (Pc1, Pc4, and Pc11) were diagnosed to the species level based on morphological characteristics, ability to grow on some selective and differential media, and biochemical reactions as Pectobacterium carotovorum. The microscopic examination of samples from bacterial growth showed short rod-shaped cells, single or paired, negative for Gram staining, and motile. The biochemical reaction results showed that they had the ability to hydrolyze artificial pectin and reduce sucrose, were negative for oxidase test, methyl red test, Fox-Proskauer test, and phenylalanine deaminase test, and positive for free oxygen test, tolerance to salinity, production of ammonia from peptone, production of gas from glucose, hydrolysis of starch, ability to consume simple sugars, hydrolysis of gelatin, and ability to grow at 38°C.

DESIGNING A RAPID, RELIABLE AND REPRODUCIBLE METHOD FOR THE DETECTION OF SALMONELLA SPP. FROM POULTRY MEAT

Salmonella is one of the most common causes of foodborne diseases among humans worldwide. Animal-derived foods are frequently tested for the presence of Salmonella spp. However, the detection of Salmonella in meat and its products is often hindered due to the presence of background normal flora, which may lead to the detection of false-positive Salmonella. The present study aimed to isolate and accurately identify Salmonella spp. from poultry meat. For this purpose, seventy poultry meat samples were collected from Lahore, Pakistan, isolated on selective and differential media, and identified using biochemical tests and polymerase chain reaction for the 16S rRNA gene of identified strains. The results of selective and differential media culturing and biochemical tests were compared with the results of 16S rRNA gene sequencing. It was inferred that the phenylalanine deaminase test and triple sugar iron tests eliminate the false-positive Salmonella isolates obtained on isolation media, and along with the PCR technique, can serve as an accurate and efficient method for the correct detection of Salmonella spp. from meat samples. In order to reduce the false-positive Salmonella isolates, a highly specific selective media must be designed which can distinguish Salmonella forming different colors of colonies from other bacteria and also cause the inhibition of non-Salmonellaisolates.

P1188ICODEXTRIN-INDUCED CHEMICAL PERITONITIS IN A PATIENT WITH CARDIORENAL SYNDROME

Abstract Background and Aims The main cause of morbidity among patients who undergo peritoneal dialysis (PD) remains peritonitis. However there are rare references in published literature about the development of sterile peritonitis related to exposure to PD materials used to overcome the complications from glucose solutions.The objective of the present case report is to enhance clinical suspicion in order to avoid unnecessary antibiotic treatment or catheter removal. Case description A 56-year-old male became dialysis dependent from June 2017 due to cardiorenal syndrome type II, after multiple hospitalizations for pulmonary edema within a year. The patient was prescribed icodextrin 7,5% as a single 10-hour nocturnal dwell with dry day period in continuous ambulatory PD .At his scheduled appointment during drainage of the nighttime dialysate, slightly cloudy effluent with a lot of pale yellow substances “sesame” like, were observed without any signs of peritonitis or pathology from the Catheter exit site based on Twardowski classification.The dialysate contained 600 cells/ml. The floating yellow substances after laboratory and light microscopy examination accumulated epithilium cells with rare macrophages were found.Due to these findings,icodextrin was discontinued and empiric antibiotic therapy started including intraperitoneal administration of vancomycin and ceftazidime .After 3 days the floating substances disappeared and the number of cells in dialysate progressively decreased but not within the normal range so empirical antifungal therapy was decided. Daily repeated aerobic, anaerobic and fungal cultures of effluent and blood were negative as well the culture of exit site. ADA (adenosine deaminase test) and β-koch culture were also negative. Computed tomography scan of abdomen and colonoscopy showed no pathology.Due to fluid overload an additional long-term dwell of icodextrin solution was initiated.The re-exposure doubled the number of cells (310 cells/ml) and a second sample was sent for cytological examination which showed plenty of hyperplastic mesothelial cells in piles and isolated, abundant mature lymphocytes, few polymorphonuclear leukocytes as well as several mast cells. Based on these observations peritoneal cavity remained empty for 24 hours. Afterwards a 4-hour exchange of glucose-containing solution of 1,36%, 2,27%, 3,86% and finally of icodextrin was held once daily. The cells were 155, 120, 105 and 450/ml respectively with lymphocytes and mast cells being predominant.Based on these data, it was considered that the exposure to icodextrin produced hypersensitivity and the empiric antibiotic therapy was discontinued.The catheter was removed and sent for culturing which was negative.The biopsy of peritoneal membrane revealed mild fibrous sclerotic lesions, fibrous texture, partially collagenized membrane lacking mesothelial lining and exhibiting sparse chronic nonspecific inflammatory infiltration involving rare neutrophilic leukocytes. Plenty of small blood vessels were observed, with no immunomorphological features including IgG4 staining. These findings were attributed to chemical peritonitis from icodextrin solution ant the patient switched dialysis modality. Discussion:the use of icodextrin in peritoneal dialysis patients has numerous advantages over glucose-based dialysates including improved ultrafiltration, better fluid control and less hypertension, especially in patients with cardiorenal syndrome. In the face of evident benefits, clinicians should, however, be aware of the potential of icodextrin to induce chemical sterile peritonitis.

Chylothorax with Transudate: An Unusual Presentation of Tuberculosis.

IntroductionTwenty-five per cent of tuberculosis patients have pleural tuberculosis, which is the third most common form of presentation. Most cases present as an exudative pleural effusion with just few cases reported as chylothorax in the literature. All pleural effusions from confirmed cases, including tuberculous chylothorax, had exudate features.AimTo describe a patient with Mycobacterium tuberculosis affecting the lungs and pleura, which laboratory testing demonstrated had features of transudate chylothorax.Patient and methodsA 70-year-old man presented with constitutional symptoms, progressive exertional dyspnoea and right pleural effusion with fibrocavitary changes on chest imaging. Thoracentesis and pleural fluid analysis revealed chylous fluid with transudate features, high triglycerides, low cholesterol content and mononuclear cell predominance. Acid-fast sputum stains and pleural fluid were negative for Mycobacterium tuberculosis as was an adenosine deaminase test for pleural effusion. Tomography-directed lung biopsy sampling of a lung nodule revealed a chronic granulomatous inflammatory process associated with the presence of acid-fast bacilli.DiscussionTuberculosis-associated chylothorax is an uncommon presentation of the disease. A recent review found only 37 cases of confirmed tuberculous chylothorax had been reported in the literature. All cases had exudate characteristics. The diagnosis of pleural tuberculosis was made through culture or testing of sputum, pleural fluid or biopsy samples in 72.2% of cases, with the rest identified by histopathology.LEARNING POINTSThe main cause of non-traumatic chylothorax is malignancy, which is found in 39–72% of cases.Few cases of transudative chylothorax have been reported in the literature; the main aetiology is chronic hepatopathy.Tuberculosis-associated chylothorax is a rare presentation of infection caused by Mycobacterium tuberculosis, an uncommon aetiology.

IgA and IgG antibody detection of mycobacterial antigens in pleural fluid and serum from pleural tuberculous patients

BackgroundA previous study demonstrated pleural fluid (PF) IgA immunodominance for the fused MT10.3:MPT64 protein in pleural tuberculosis (PLTB) cases. However, no clue on the role of IgA and IgG against this and other antigens in PF and serum concerning improved diagnosis is available. Thus, the aim of the present study was to validate PF IgA-MT10.3:MPT64 and evaluate PF and serum IgA and IgG reactivity against this protein, its peptides (F2) and single MPT64, MT10.3 and the PPE59 mycobacterial specific antigens. IgA and IgG ELISA were measured against the antigen in PLTB (n = 29) and other non-TB pleurisy (n = 39) patient samples.ResultsThe immunodominance of PF IgA-MT10.3:MPT64 was confirmed in PLTB (86.2%) followed by PPE59 (62%), while serum IgA-F2 exhibited 51.7% sensitivity. PF and serum IgG-MT10.3:MPT64 led to 65.5 and 51.7% sensitivity, respectively. However, MT10.3 and MPT64 displayed overall lower sensitivity (≤34.5) for both antibodies. All results at 95% fixed specificity. Combinatory results indicated 93.1% sensitivity for PF IgA-MT10.3:MPT64/−PPE59 and IgA/IgG-MT10.3:MPT64 at 92.3% specificity, followed by IgA-MT10.3:MPT64/−MPT64 or /−F2 (89.6%) without jeopardizing specificity (94.9%). The combinatory results of the PF adenosine deaminase test (ADA) and IgA-MT10.3:MPT64/−F2 demonstrated the highest sensitivity (96.6%), with a specificity of 92.3%.ConclusionsThe PF IgA-MT10:MPT64 immune dominance was validated in PLTB, and its combinatory results with PPE59 or MPT64 or F2 antigens as well as with IgG, are reported herein for the first time, improving their potential to assist diagnosis. Combining PF-ADA and IgA-MT10.3:MPT64/−F2 results achieved better accuracy. Moreover, serum IgG, although less accurate, displays potential beyond microbiological tests.

Disseminated TB Presenting as Knee Arthritis

SESSION TITLE: Fungal Infections 1 SESSION TYPE: Affiliate Case Report Poster PRESENTED ON: Tuesday, October 31, 2017 at 01:30 PM - 02:30 PM INTRODUCTION: Disseminated tuberculosis (TB) can lead to significant morbidity and mortality. The presentation is variable and dependent on the organs affected. Monoarticular arthritis of knee is uncommon especially in an immunocompetent host and in developed settings. High index of clinical suspicion is required as the condition may imitate other forms of inflammatory arthritis and may have an indolent course. Diagnosis can be challenging and delayed given the focal subacute presentation. We present a case of disseminated TB presenting as knee arthritis. CASE PRESENTATION: A 42-year-old-male presented with 18 month history of worsening left knee pain. It has progressed with inability to bear weight for 3 weeks. He had weight loss but no cardio-respiratory symptoms. A recent travel to South East Asia was noted. Clinical examination revealed a small left knee effusion and reduced range of motion. Rest of the examination was unremarkable. Knee XR showed sclerotic changes. Knee MRI showed non-haemorrhagic synovitis causing significant cartilage disruption and bony erosion. The inflammatory markers were raised. Knee aspiration showed acid fast bacilli and raised white cells. The patient proceeded an arthroscopic washout with good surgical outcome. Further imaging reveals mild bilateral pleural effusion. He developed gross haematuria and imaging identified a right ureteric lesion. Urine microbiology and pleural fluid microbiology was positive for Mycobacterium Tuberculosis. The diagnosis of disseminated TB was made and the patient was started on anti-tuberculosis agents. At follow up the patient was able to complete weight bear and had responded well to treatment. DISCUSSION: This case represents a rare extra-pulmonary presentation of an uncommon disease process in an immunocompetent host. Osteoarticular TB is typically result of direct haematogenous spread from primary focus. The presentation is indolent with subacute pain, joint swelling and stiffness with significant overlap with more common monoarthritidis such as crystal or bacterial monoarthritis. A significant delay is noted between symptoms and treatment with time range upto 104 weeks which can contribute to significant morbidity and mortality especially if it is initial presentation of disseminated TB. The diagnosis is difficult. Biochemistry of synovial fluid is not helpful and synovial fluid AFB is positive only in 20% cases. Culture can be positive in 80% cases and biopsy synovium may show granuloma. Adenosine deaminase (ADA) should be sent as may help early diagnosis. CONCLUSIONS: Knee arthritis secondary to TB is rare and insidious. Delayed TB diagnosis can be avoided by high clinical suspicion in cases where patients have constitutional symptoms, focal joint inflammatory pathology and a travel history in TB endemic regions. Synovial aspiration, Ziehl-Neelsen staining, culture and adenosine deaminase test are recommended if TB is a differential. Reference #1: Acta Reumatol Port.2016;41:256-159 DISCLOSURE: The following authors have nothing to disclose: Sumit Mehra, Aaron Gaekwad No Product/Research Disclosure Information

Ascites and Adnexal Mass with Raised CA125: How Arduous can be the Path of Diagnosis

Ascites, adnexal mass and elevated CA125 levels almost always suggest advanced ovarian carcinoma. We present a case of a 37 years old multiparous lady who presented with such a classical picture. Radiological picture was suggestive of ovarian carcinoma with peritoneal metastasis. However, ascitic fluid cytology was negative for malignant cells. A differential diagnosis of tubercular mass was made. Ascitic fluid was sent for adenosine deaminase test that was negative. Fine needle aspiration cytology failed to reveal any sufficient sample for evaluation. Open laparotomy and biopsy was done that showed granulomas suggestive of tuberculosis. Category one anti tubercular treatment was started and symptoms resolved within one month.

Modified TB rapid test by proteinase K for rapid diagnosis of pleural tuberculosis.

The diagnosis of pleural tuberculosis continues to be a challenge due to the low sensitivity of traditional diagnostic methods. Better and more rapid tests are needed for diagnosis of pleural TB. In this study, pleural fluids were tested with rapid test to determine Mycobacterium tuberculosis (MTB antigen). Affinity chromatography was used to purify specific polyclonal antibodies against MTB antigen. Pleural samples after decontamination were treated with proteinase K. Rapid test for pleural fluids was prepared by specific antibody. Rapid test was performed on 85 pleural fluid patients. The patients had a mean age of 46.55 ± 15.96 years and 38 were men. The performance of rapid test, using proteinase K, was found to be the most impressive: sensitivity 93%, specificity 94%, PPV 90%, and NPV 96% compared with adenosine deaminase test (ADA), PCR, smear, and culture. The present study did demonstrate that modified TB rapid test can substantially improve the diagnosis of extrapulmonary TB.

Market assessment of tuberculosis diagnostics in South Africa, 2012-2013.

To assess the current served available market of tuberculosis (TB) diagnostics in South Africa in the public and private sectors. Public and private sector test volumes and unit costs were collected for tuberculin skin tests, interferon-gamma release assays, smear microscopy, culture, speciation, Xpert MTB/RIF, other nucleic acid amplification tests, drug susceptibility testing and adenosine deaminase tests. In 2012, during Xpert scale-up, the public and private sectors performed a total of 9.2 million TB diagnostic tests, at an estimated total value of US$98 million. The public sector accounted for 93% of the overall test volume and value. There were no major differences in the types of tests performed in both sectors, with microscopy and culture accounting for the majority of tests performed (72%). In 2013, the public sector market value increased to US$101 million (a 10% increase over 2012): Xpert volumes increased by 166%, while total TB test volumes decreased by 12% compared to 2012. South Africa has a substantial TB diagnostic market in terms of both volume and value. The roll-out of Xpert provides insights into how markets change in volume and value with the introduction of new tools.

Ammonia does not interfere with the Diazyme adenosine deaminase test

Ammonia does not interfere with the Diazyme adenosine deaminase test

Cytidine deamination assay to differentiate Staphylococcus aureus from other staphylococci

Adoption of the property of cytidine (cytosine-beta-d-riboside) deamination in staphylococci to distinguish Staphylococcus aureus from other staphylococci. A total of 560 staphylococcal strains were examined. The test demonstrated a sensitivity of 97.1% and a specificity of 98.8%. Of the 249 S. aureus strains (115 oxacillin-resistant) 58 strains were coagulase-negative S. aureus and another 16 strains were clumping factor-negative S. aureus. The 74 deficient S. aureus strains were identified by 16S rRNA gene sequencing and further investigated by spa typing and 13 spa types were found. The cytidine deaminase test (CDT) is useful especially for distinguishing coagulase- and clumping factor-negative S. aureus from other staphylococci and the results correlated well with 16S rRNA sequencing and the polymerase chain reaction (PCR) amplification of the nuc gene. Cytidine deamination assay differentiates S. aureus from other staphylococci. This method is fast (6 h) and reliable in distinguishing between non-S. aureus and the defective (coagulase-negative, clumping factor-negative) S. aureus isolates which could have major consequences for therapy.

A systematic review of rapid diagnostic tests for the detection of tuberculosis infection

To evaluate the effectiveness of available rapid diagnostic tests to identify tuberculosis (TB) infection. Electronic databases were searched from 1975 to August 2003 for tests for active TB and to March 2004 for tests for latent tuberculosis infection (LTBI). Studies were selected and evaluated that (1) tested for LTBI, (2) compared tuberculin skin test (TST) and interferon-gamma assays based on ESAT-6 and CFP-10 antigens and (3) provided information on TB exposure or bacille Calmette-Guerin (BCG) vaccination or HIV status. For each test comparison, the sensitivity, specificity and 95% confidence intervals (CIs) were calculated. Sources of heterogeneity were investigated by adding covariates to the standard regression model. The authors examined whether interferon-gamma assays were more strongly associated with high versus low TB exposure than TST. Odds ratios (ORs) were calculated for the association between test results and exposures from each study along with their 95% CIs. Within each study, the OR value for one test was divided by that for another to produce a ratio of OR (ROR). A total of 212 studies were included, providing 368 data sets. A further 19 studies assessing fully automated liquid culture were included. Overall, nucleic acid amplification test (NAAT) accuracy was far superior when applied to respiratory samples as opposed to other body fluids. The better quality in-house studies, were, for pulmonary TB, much better at ruling out TB than the commercial tests (higher sensitivity), but were less good at ruling it in (lower specificity), but it is not possible to recommend any one over another owing to a lack of direct test comparisons. The specificity of NAAT tests was high when applied to body fluids, for example for TB meningitis and pleural TB, but sensitivity was poor, indicating that these tests cannot be used reliably to rule out TB. High specificity estimates suggest that NAAT tests should be the first-line test for ruling in TB meningitis, but that they need to be combined with the result of other tests in order to rule out disease. Evidence for NAAT tests in other forms of TB and for phage-based tests is significantly less prolific than for those above and further research is needed to establish accuracy. There is no evidence to support the use of adenosine deaminase (ADA) tests for diagnosis of pulmonary TB; however, there is considerable evidence to support their use for diagnosis of pleural TB and to a slightly lesser extent for TB meningitis. Anti-TB antibody test performance was universally poor, regardless of type of TB. Fully automated liquid culture methods were superior to culture on solid media, in terms of their speed and their precision. In total, 13 studies were included. Assays based on RD1 specific antigens, ESAT-6 or CFP-10, correlate better with intensity of exposure, and therefore are more likely than TST/purified protein derivative (PPD)-based assays to detect LTBI accurately. An additional advantage is that they are more likely to be independent of BCG vaccination status and HIV status. The NAAT tests provide a reliable way of increasing the specificity of diagnosis (ruling in disease) but sensitivity is too poor to rule out disease, especially in smear-negative (paucibacillary) disease where clinical diagnosis is equivocal and where the clinical need is greatest. For extra-pulmonary TB, clinical judgement has both poor sensitivity and specificity. For pleural TB and TB meningitis, adenosine deaminase tests have high sensitivity but limited specificity. NAATs have high specificity and could be used alongside ADA (or interferon-gamma) to increase sensitivity for ruling out disease and NAAT for high specificity to rule it in. All studies from low-prevalence countries strongly suggest that the RD1 antigen-based assays are more accurate than TST- and PPD-based assays for diagnosis of LTBI. If their superior diagnostic capability is found to hold up in routine clinical practice, they could confer several advantages on TB control programmes. Further research for active TB needs to establish diagnostic accuracy in a wide spectrum of patients, against an appropriate reference test, and avoiding the major sources of bias. For LTBI, research needs to address different epidemiological and clinical settings, to evaluate the performance of the main existing commercial assays in head-to-head comparison in both developed and developing countries, and to assess the role of adding more TB-specific antigens to try to improve diagnostic sensitivity.

Comparison of Different Laboratory Routine Methods with Adenosine Deaminase Test for Diagnosis of Tuberculous Pericarditis in Two Iranian Teaching Hospitals, Tehran, Iran

In this study, laboratory routine tests were compared with adenosine deaminase (ADA) test for diagnosis of tuberculous pericarditis. Sampling was performed among 30 patients admitted to two Iranian teaching hospitals (Imam and Modarres). For each patient two specimens were obtained from the pericardial fluid and biopsy. Pericardial fluid was used for staining, culture and measuring of ADA activity. The biopsy specimens were homogenized and cultured on Lowenstein-jensen media too and examined by H & E stain for presence of caseous granulomas and tubercule bacilli. In this survey, the ADA activity level of less than 45 μL-1 in pericardial fluid were determined as negative, while more than 45 μL-1 were considered as positive reaction indicating of tuberculous pericarditis. In this study, from a total of 30 subjects, tuberculous pericarditis was diagnosed by routine laboratory tests in 13 patients who all had clinical symptoms of the disease. Tuberculous pericarditis was diagnosed by positive results of pericardial fluid cultures in 6 of 13 patients (46.2), by pericardial biopsy cultures in 6 patients (46.2), by pericardial fluid staining in 3 patients (23.1) and by tuberculin skin test in 10 patients (76.9). Finally we observed that all of 13 patients with tuberculous pericarditis had ADA levels of more than 45 μL-1 in their pericardial fluids. The results of the present study confirmed that high levels of ADA have a prognostic value and due to its high specificity and sensitivity and also being faster and easier than laboratory routine tests, so this test can utilized as effective diagnostic method for diagnosis of tuberculous pericarditis. © 2006 Asian Network for Scientific Information.

Rapid detection of urinary tract infection caused byEscherichia coli orProteeae species

Beta-glucuronidase and phenylalanine deaminase tests for screening urine specimens to provide rapid reporting (2 hours) of Escherichia coli and Proteeae species were evaluated. A total of 2,318 urine specimens were processed for these two tests. For the detection of Escherichia coli in urine, the sensitivity and specificity of the beta-glucuronidase test were 0.96 and 0.99 respectively; predictive positive and negative values were 0.97 and 0.99. For the detection of Proteeae in urine, the sensitivity and specificity of the phenylalanine test were 0.92 and 0.99. Predictive values were 0.99 for a negative test and 0.95 for a positive test. The data suggest that beta-glucuronidase and phenylalanine deaminase tests performed directly in urine sediment have potential usefulness as rapid and reliable tests that are easy to perform and interpret for the diagnosis of urinary tract infections caused by Escherichia coli or Proteeae species.

Diagnostic value of ascites gamma interferon levels in tuberculous peritonitis. Comparison with adenosine deaminase activity

The value of ascites gamma interferon concentration and ascites adenosine deaminase activity in distinguishing tuberculosis from other causes of ascites was examined in a prospective study of 86 patients with ascites, including 16 with tuberculous peritonitis. Gamma interferon concentration was higher in tuberculous peritonitis than in the other causes of ascites (p < 0.0001), and a cut-off between 3 and 9 u/ml reached a sensitivity and a specificity of 100%. The mean (± SD) gamma interferon level in tuberculous ascites was 39.3 ± 18.3 u/ml in patients seronegative for HIV and 14.2 ± 4.7 μ/ml in patients with AIDS (p = 0.01). Adenosine deaminase activity in tuberculous ascites was also higher than in the other causes of ascites (p < 0.0001), and a cut-off of 40 u/l reached a sensitivity of 100% and a specificity of 97%. The two false positives for adenosine deaminase test were true negatives for the gamma interferon test. There was no significant correlation between gamma interferon concentration and adenosine deaminase activity either in tuberculous ascitis or in any other group. This study suggests that ascites gamma interferon determination may be very useful in the screening of tuberculous peritonitis, but Its cost makes it advisable to use adenosine deaminase activity as a routine test, at least in areas where tuberculosis is endemic.

Rare occurrence of Proteus vulgaris in faeces: a reason for its rare association with urinary tract infections.

The faecal carriage rates of different species of Proteeae were assessed in studies with 220 faecal isolates from 219 individuals of whom approximately one-third were well and the remainder had gastro-enteritis. As a result of the development of new media that allowed replacement of the phenylalanine deaminase test with the tryptophan deaminase test and made it possible to combine tests for indole and urease production and for hydrogen sulphide and ornithine decarboxylase formation in two single-tube tests, all strains were speciated with speed, economy and accuracy. Most (96%) isolates were either Proteus mirabilis (62%) or Morganella morgani (34%). The significance of these findings in relation to urinary tract infection is discussed. P. vulgaris was found in only one (0.45%) faecal specimen and this rarity of carriage in faeces is believed to be the main reason for its rare association with urinary tract infections. The frequent association of M. morgani, in the absence of other enteropathogenic bacteria, with severe gastroenteritis was noted with interest.