Evaluation of different culture methods for the diagnosis of peritonitis in patients on continuous ambulatory peritoneal dialysis

A total of 170 continuous ambulatory peritoneal dialysis (CAPD) fluids were processed by various culture methods, including direct inoculation of the centrifuged sediment, inoculation into automated blood culture bottles, water lysis, Tween-80 incorporated blood agar, and Triton-X treatment of the specimen. Of 170 CAPD fluids, 127 showed the growth of bacteria/fungi. Sixty-three fluids showed growth by all methods, the water lysis alone detected 24 additional positive cultures, while Tween-80 blood agar and Triton-X yielded 30 additional positive cultures. A combination of water lysis, Tween-80 blood agar and Triton-X treatment of the CAPD fluid is recommended for diagnosis of CAPD peritonitis in resource-limited settings.     

利用BACTEC 960分枝杆菌分析系统对分枝杆菌进行快速菌型鉴定方法的研究

目的:探索一种快速的分枝杆菌菌型鉴定方法。方法:用BACTEC 960分枝杆菌系统(960)和传统的改良罗氏培养基法(L-J法),对分枝杆菌标准菌株及临床分离菌株,同时进行菌型鉴定的对照研究,确定本法进行菌型鉴定的最佳药物浓度及具体优势。结果:本法进行快速菌型鉴定所需药物浓度为:噻吩-2-羧基肼(TCH)5.0μg/mL,对硝基苯甲酸(PNB)500μg/mL。进行快速菌型鉴定所需时间平均为6.7天,较L-J法平均提前23.3天。结论:本法明显缩短了分枝杆菌进行菌型鉴定的时间,为临床对分枝杆菌感染的菌型提供快速的诊断依据,并及时指导临床用药。     

BACTEC MGIT 960用于结核分枝杆菌直接药敏试验的研究

目的探讨BACTEC MGIT 960系统在结核分枝杆菌直接药敏试验的临床应用价值。方法对200株临床涂阳痰标本应用BACTEC MGIT 960系统进行一线抗结核药（链霉素、异烟肼、利福平、乙胺丁醇）结核分枝杆菌直接药敏试验,并与同步进行的BACTEC MGIT 960间接药敏试验及传统改良罗氏（L-J）比例法药敏试验进行比较,从结果报告时间和符合率等方面进行评价。统计学分析分别采用配对资料的t检验和Kappa检验。结果 BACTEC MGIT960直接药敏试验报告时间为（9.7±3.1）d,与BACTEC MGIT 960间接药敏试验报告时间（17.5±6.6）d比较差异有统计学意义（t=14.7,P〈0.01）,与L-J法报告时间（50.4±8.6）d比较差异有统计学意义（t=73.4,P〈0.01）;4种一线抗结核药物链霉素、异烟肼、利福平、乙胺丁醇药敏BACTEC MGIT 960直接法与BACTEC MGIT 960间接法药敏结果总符合率为97.3%,BACTEC MGIT 960直接法与L-J法药敏结果总符合率为96.2%。结论 BACTEC MGIT 960直接药敏试验快速、准确,可用于结核分枝杆菌的药物敏感性检测,利于耐药结核病的早期诊断和治疗。     

An in vitro assessment of the antineoplastic potential of 2H-1,3-Oxazine-2,6(3H)-dione (3-oxauracil), a novel pyrimidine

The pyrimidine (uracil) analogue 3-oxauracil (OU) previously had been shown to completely inhibit the growth of E. coli B and decrease by 96% the replication of herpes simplex virus type 2 when present in the culture fluid at a concentration of 10² µM. Limited in vivo studies in mice demonstrated antiviral effects without significant toxicity when given i.p. daily for two weeks at a concentration of 3.23 mg/kg. However, the antineoplastic properties of OU were unknown. We assessed the ability of OU to inhibit the proliferation of various human tumor cell lines (3 pancreatic, 1 colon, 1 neuroendocrine, and 1 lung) in an in vitro radiometric (Bactec) system. In the pancreatic lines (RWP-2, MiaPaCa-2, and PANC-1), the colon line (HT-29), the neuroendocrine line (COLO 320DM), and the lung cancer cell line (SK-MES-1), OU at a concentration of 10³ µM, produced a dramatic decrease in percent cell survival. When compared with cytotoxic drugs of choice for these tumor cells (gemcitabine, 5-fluorouracil, and adriamycin, respectively) a significantly higher concentration of OU was required usually to achieve comparable results with two exceptions. These were the HT-29 and the COLO 320DM cell lines. These results indicate OU has significant (p < 0.05) cytotoxic activity against pancreatic, colon, neuroendocrine, and nonsmall cell lung cancer lines, when compared to untreated control cultures. Additional in vivo testing of this potential antineoplastic agent is warranted.     

Comparison of IS6110 and ‘short fragment’ devR (Rv3133c) gene targets with phenotypic methods for diagnosis of Mycobacterium tuberculosis

Background

Tuberculosis (TB), declared a global emergency in 1993 by the WHO, remains a worldwide public health problem. Rapid diagnosis is required for treatment and prevention. This study compares genotypic methods using two gene targets [IS6110 and 'short fragment' devR (Rv3133c)] with phenotypic methods [Lowenstein Jensen (LJ) and BACTEC 460] for the diagnosis of TB while using Ziehl Neelsen (ZN) staining as the gold standard.

Methods

56 clinical TB samples from a tertiary care apex center along with 50 healthy control samples, excluding samples from patients already on ATT were processed by routine USP methodology. Smears were graded by ZN stain. Solid media (LJ) and liquid media (BACTEC 460) were used along with IS6110 and 'short fragment' devR (Rv3133c) specific gene amplification and comparatively analyzed.

Results

50/56 samples were positive by phenotypic methods, 53 by IS6110 and 45 by devR (Rv3133c) amplification. 38 samples were positive by both phenotypic and genotypic methods. IS6110 detected six and devR (Rv3133c) detected five phenotypically negative samples. Both IS6110 and devR (Rv3133c) were positive in 42 samples. 11 devR (Rv3133c) negative samples were positive by IS6110 and three IS6110 negative samples were positive by 'short fragment' devR (Rv3133c). Compared to phenotypic methods, the sensitivity, specificity, positive and negative predictive values of IS6110 was 94%, 89.29%, 88.68% and 94.34% while that of devR (Rv3133c) was 80%, 91.07%, 88.89% and 83.61% respectively.

Conclusion

Simultaneous use of both phenotypic and genotypic methods increases the yield of positive results.     

Comparison of IS6110 and ‘short fragment’ devR (Rv3133c) gene targets with phenotypic methods for diagnosis of Mycobacterium tuberculosis

Background

Tuberculosis (TB), declared a global emergency in 1993 by the WHO, remains a worldwide public health problem. Rapid diagnosis is required for treatment and prevention. This study compares genotypic methods using two gene targets [IS6110 and ''short fragment'' devR (Rv3133c)] with phenotypic methods [Lowenstein Jensen (LJ) and BACTEC 460] for the diagnosis of TB while using Ziehl Neelsen (ZN) staining as the gold standard.

Methods

56 clinical TB samples from a tertiary care apex center along with 50 healthy control samples, excluding samples from patients already on ATT were processed by routine USP methodology. Smears were graded by ZN stain. Solid media (LJ) and liquid media (BACTEC 460) were used along with IS6110 and ''short fragment'' devR (Rv3133c) specific gene amplification and comparatively analyzed.

Results

50/56 samples were positive by phenotypic methods, 53 by IS6110 and 45 by devR (Rv3133c) amplification. 38 samples were positive by both phenotypic and genotypic methods. IS6110 detected six and devR (Rv3133c) detected five phenotypically negative samples. Both IS6110 and devR (Rv3133c) were positive in 42 samples. 11 devR (Rv3133c) negative samples were positive by IS6110 and three IS6110 negative samples were positive by ''short fragment'' devR (Rv3133c). Compared to phenotypic methods, the sensitivity, specificity, positive and negative predictive values of IS6110 was 94%, 89.29%, 88.68% and 94.34% while that of devR (Rv3133c) was 80%, 91.07%, 88.89% and 83.61% respectively.

Conclusion

Simultaneous use of both phenotypic and genotypic methods increases the yield of positive results.     

The efficacy of diagnostic battery in Pott's disease: A prospective study

Background:

The diagnosis of Pott''s disease is mostly based on clinicoradiological observations substantiated by the bacterial culture, staining and histopathology. Since, no single technique is enough to conclude Pott''s disease in diagnosis, the present study was undertaken to correlate the clinicoradiological, microbiological, histopathological and molecular method to evaluate the effectiveness in diagnosis of Pott''s disease.

Materials and Methods:

62 clinicoradiologically suspected cases of Pott''s disease were included in this study. The specimens for diagnostic work up were collected either during surgery or by computed tomography guided fine needle aspiration. All these specimens were tested for tuberculosis (TB) through Ziehl-Neelsen (ZN) microscopy, BACTEC culture, histopathology and polymerase chain reaction (PCR). The final diagnosis was established by the results of performed tests and clinicoradiological improvement of cases at the end of 6 months on anti tubercular treatment.

Results:

Out of 62 cases, 7 were excluded from this study as these were turned out to be neoplastic lesions on histopathology. Amongst remaining 55 cases, the TB was diagnosed in 39 (71%) on histopathology, 37 (67.5%) on PCR, 27 (49%) on BACTEC culture and 20 (36.3%) on ZN microscopy. Ultimately 45 cases were tested as positive and 10 were detected as negative for TB in combination of ZN microscopy, BACTEC culture and histopathology. PCR was positive in 37 of 45 cases and 10/55 cases remained negative. On clinical analysis of these 10 cases, it was noted that these were cases of relapse/poor compliance. The combination of PCR and histopathology was also shown positive for TB in 45 cases. Hence, the PCR showed a fair positive agreement (Κ^c = 0.63) against the combined results of all performed traditional methods.

Conclusions:

The combination of PCR and histopathology is a rapid and efficient tool for diagnosis of Pott''s disease.     

BACTEC MGIT-960快速检测分枝杆菌的临床应用研究

目的探讨BACTEC MGIT-960全自动分枝杆菌检测技术在结核病诊治中的应用价值。方法用BACTEC MGIT-960对不同种类标本进行结核杆菌分离培养及药敏试验,并与改良罗氏培养法和BACTEC-460系统进行比较。结果BACTEC-960全自动分枝杆菌检测技术初代分离阳性时间平均为9.8天,药敏平均为7.5天,明显短于改良罗氏培养(28.5天和22.1天),与BACTEC-460(8.8天和6.5天)结果接近。486份各类标本总阳性率46.50%,其中痰标本为54.02%。BACTEC MGIT-960药敏试验结果,与BACTEC-460、L-J法总符合率分别为98.54%和95.79%。结论BACTEC MGIT-960全自动分枝杆菌检测技术是目前一种比较理想的快速检测结核菌的方法。     

In-vitro anti-Mycobacterium tuberculosis effect of Eugenol

Background/ObjectivesMycobacterium tuberculosis, the causative agent of tuberculosis has developed resistance to most of the available antimicrobials. Therefore research on the detection of new antimicrobials against Mycobacterium tuberculosis is needed urgently. Essential oils extracted from plants have been shown to have anti-Mycobacterium tuberculosis effect in in-vitro experiments. Essential oil contains many chemicals and any one or more than one chemical may have the anti-Mycobacterium tuberculosis effect. Eugenol is one such chemical in the essential oil and the anti-Mycobacterium tuberculosis effect of eugenol is investigated.MethodsThe anti-Mycobacterium tuberculosis effect of eugenol was evaluated against H37Rv and twelve clinical isolates of Mycobacterium tuberculosis in the BD BACTEC MGIT instrument using different volumes of eugenol.ResultsH37Rv and all the twelve clinical isolates of Mycobacterium tuberculosis were inhibited by eugenol. The minimal inhibitory concentration of H37Rv was 2.5 μl (2.67 mg) and those of the clinical isolates of Mycobacterium tuberculosis ranged from to 2.5 μl (2.67 mg) to 10 μl (10.68 mg).ConclusionEugenol has anti-Mycobacterium tuberculosis effect in the in-vitro BD BACTEC MGIT method.     

应用BACTEC MGIT 960分析临床结核菌株耐药性分析

目的研究我院结核病患者的抗结核药物耐药特点。方法我院就医的结核病患者抗结核药物的敏感性试验结果,分析临床抗结核药物的耐药现状。结果 2008～2010年,耐药菌株为4825株(耐药率为66.68%,4825/7236,MDR为1142株,XDR为105株)。XDR-TB比例2008、2009、2010年分别为1.73%(30/1732)、1.33%(34/2548)、1.39%(41/2956)。结论结核病患者的抗结核药物的耐药形势依然严峻,加强抗结核药物的耐药性监测,合理使用药物非常必要。