Detection of mycobacterium tuberculosis in respiratory and nonrespiratory clinical specimen using the BACTEC MGIT960 culture and DNA strand displacement amplification [SDA] assay

Direct DNA amplification techniques have provided significant tool for the diagnosis of pulmonary tuberculosis [PTB]. The efficacy of such time-saving techniques, compared to M. tuberculosis [MTB] culture in the diagnosis of extrapulmonary tuberculosis [EPTB] is improving with the invention of new nucleic acid amplification technologies. The isolation of MTB strains and the ability to obtain an anti-tuberculous drugs susceptibility profile are considered as advantages which favor the use of culture-based diagnostic assays. Automated MTB culture and antibiogram assays provide sufficient sensitivity and specificity and are timesaving in diagnosing respiratory and non-respiratory MTB infections. Since the performance of the strand displacement amplification [SDA] technique in diagnosis of PTB and EPTB lesions is being assessed worldwide, this study was performed to evaluate the use of BDProbeTec SDA [Becton Dickinson, Sparks, Maryland, USA] -recently introduced to our lab- to identify MTB in both PTB and EPTB clinical specimens and to compare it with the "gold standard" culture assays in the lab. The latter included the automated BACTEC MGIT960 System [Becton Dickinson] and subsequent culture on L-J medium followed by biochemical identification of MTB strains. Specimens were collected, prospectively, from 114 patients with clinically suspected pulmonary [n=60] and extrapulmonary tuberculosis [n=54]. The EPTB specimens were: fine needle aspirates [FNA; n=30], pus [n=6], CSF [n=10], and pleural fluid [n=8]. All specimens were initially screened microscopically after ZN staining. Diff-Quik staining and microscopic examination was performed on FNA and pus specimens for cytopathologic findings suggestive of MTB lesion. MTB strains were identified by subculture on L-J medium and subsequent niacin, nitrate reduction and catalase tests. SDA identified MTB strains in 43 out of 60 PTB specimens, and 17 of 54 EPTB specimens. The sensitivity and specificity of SDA in testing PTB specimens were 93% and 88%, while in testing EPTB specimens they were 83% and 94%, respectively. Generally, SDA sensitivity was lower in AF smear-negative than AF smear-positive samples. The sensitivity [100%] and specificity [89%] of SDA when used for FNA samples were much higher than for CSF and pleural fluid. Cytopathologic examination of stained tissue/pus smears was valuable aid in the diagnosis of EPTB infections. Both SDA and culture techniques could complement each other to generate many advantages: excluding MTB infection in patients with AF smear-positive samples when NTM is suspected; confirming MTB in a number of suspected samples; providing rapid diagnosis of MTB and higher sensitivity for diagnosis of EPTB in FNA specimens. On the other hand, SDA has poor sensitivity in fluid samples as pleura and CSF, and is not suitable for assessing efficiency of antituberculous drug therapy, a mission that could be successfully achieved by BACTEC MGIT automated TB culture assays

reflection of control programs of parasitic diseases upon gastrointestinal helminthiasis in Dakahlia governorate, Egypt

The study area included Mansoura city as an urban area and Gogar village as a rural area. One thousand individuals were randomly selected from each area. Different methods of stool examination, perianal swab and urine examination of all participants revealed that the incidence in Mansoura city was in a descending order Heterophyes heterophyes 6.4%; Enterobius vermicularis 3.9%; Hymenolepis nana 2.2%; Schistosoma mansoni 0.5%; Trichostrongylus colubriformis; Strongyloides stercoralis and Fasciola sp. were recorded as 0.2% of each. Taenia saginata, Ascaris lumbricoides and Trichocephalus trichiuris were recorded as 0. 1% of each. Neither Ancylostoma duodenale nor Hymenolepis diminuta was recorded. In Gogar, the parasitic infection was H. hetephyes 4.5%; E. vermicularis 4.1%; H. nana 3.3%; S. mansoni 1.6%; T. colubriformis 0.9%; S. stercoralis 0.5%. Fasciola sp. 0.4%; T. saginata, A. lumbricoides, H. diminuta, A. duodenale and T. trichiuris were recorded as 0.1% of each. None S. haematobium was detected in both areas. So, the infection rates of H. heterophyes, E. vermicularis, H. nana S. mansoni, Fasciola sp., T. colubriformis and S. stercoralis were relatively high the rural than in urban area. This was not surprising since the socioeconomic, hygienic conditions and medical services were relative high in the city than in the village. No doubt, the identifications of parasitosis pave the way for feasible treatment and control measures

Biological and ecological studies on the myiasis producing larvae of Megaselia scalaris with special morphology by scanning electron microscopy

Laboratory study was conducted on the biology of the phorid fly Megaselia sacalaris. The influence of 3 constant temperatures and various larval densities was researched in the laboratory as these relate to mean life stage rate of development and survival. Flay development on a synthetic diet at 25°C. 75=2% RH and 18 hr photophase was used as the standard. Mean times for development and survival were egg incubation 16.3 h [97.6%]; larval period 7.3 days [97.6%]; pupal period 9.8 days [95.8%, 91.6%]; adult longevity 29.9 days, 24.8 days. Fecundity was 664.8 eggs. One generation required 19.7 days. Data are presented on the influence of 20°C and 15°C on the duration of survival and fecundity life-stages. Theoretical lower thresholds of development for life stages are reported. The adverse effect of larval crowding was reflected at the 100 larvae/10 g diet medium as larval and pupal periods increased. At the 200 larvae/10g diet medium larval survival declined pupal survival decline began at 100/10 g level. Fecundity was not significant altered. The ultrastructure of the larval stages of M. scalaris was studied by scanning electron microscopy [SEM]. Significant changes in morphological features were observed in the anterior and posterior spiracles, but only minimal changes in the labium and mouth-hooks were seen. The ultrastructure of M. scalaris larvae not only provided the chronological transformation of the larval instars, but also can be used to explain their feeding behavior and mode of respiration. Besides, morphological structures useful for specific identification of first and second-instar larvae collected from human corpses may be used in forensic practice

Sarcocystosis of sarcocystis felis in cats

The features of S. felis sarcocystosis in muscles of the domestic cats [Felis domesticus] were studied. A complete clinical history, post mortem, and histopathologic examinations were done for each cat. Multiple protozoan elliptical cysts were in the skeletal muscles, heart, and diaphragm muscles of 3/17 [17.6%] adult cats. Ultrastructural characteristics of the brady-zoites and cyst wall were consistent with those descried for S. felis in bobcat and domestic cat. Clinicopathological study in 3 cats showed hypertrophy cardiomyopathy and lymphosarcoma associated with S. felis. Tissue samples showed a spectrum of pathological changes such as multi-focal subacute myocarditis and multi-focal subarachnoid lymphocytic infiltration. DNA extracted from muscles diaphragm with cysts was tested by PCR and sequence analyses of ssurRNA gene. The phylogenetic reconstructions using neighbor-joining method showed that S. felis is closely related to S. neurona. The results were illustrated and photographed and peer discussed.

Clinico-epidemiological study of human fascioliasis in an endemic focus in Dakahlia governorate, Egypt

Human fascioliasis is increasing in the Nile Delta particularly in Dakahlia Governorate, where it reached 7.47%. In this study, the tetrad of fascioliasis was established as high eosinophilia [100%] fever [85.6%], painful hepatomegaly [81.93%] and anaemia [100%]. The laboratory results showed ESR accelerated in 87%, ALT elevated in 21.5%. AST elevated in 21.9%. S. bilirubin elevated in 16.5%, gamma GT elevated in 80.6% and SAP elevated in 76.4%. Abdominal ultrasonography showed variable findings, as hepatomegaly, splenomegaly, periportal fibrosis, thickened wall of gall bladder, dilated common bile duct, dilated biliary radicals [partial], dilated common bile duct and biliary radicals [total], Fasciola worms in gall bladder, Fasciola worms in common bile duct, stones in gall bladder, stones in bile duct, cystic lesions in the liver, focal lesions in the liver and ascitis. The highest was hepatomegaly in 81.93% of fascioliasis patients and the lowest was biliary dilated radicles [partial] in 0.26%

Coccidiosis among malnourished children in Mansoura, Dakahlia, governorate, Egypt

Stool samples of 36 malnouished and 36 healthy control children were examined for oocysts of Cryptosporidium parvum, Cyclospora cayetanensis Isospora belli, and Microsporidium. C. parvum infection [single and mixed] was detected in 13.9% and 5.6% in malnourished and control children respectively. C. cayetanensis oocysts were detected in 5.6% malnourished children and in 2.8% of control group. I. belli oocysts were detected only in malnourished children 2.8%. On the other hand, no Microsporidium oocysts were detected in both malnourished and control children

Laboratory evaluation of the insecticidal activity of camphor on the development of oestrus ovis larvae

The essential oil of E. globules leaves or camphor against the maturation of Oestrus ovis larvae was evaluated at the laboratory conditions. Camphor at concentrations 1:0 and 1.1 showed 100% mortality rate. At concentrations of 1:2-1:6 the mortality rate ranged between 45-98%. On the other hand, 38 or 27.5% of the developed pupae emerged to adults but only 36.8% of them were fertile. Camphor is safely used in medicine. So, it is recommended in controlling the zoonotic myiasis producer, O. ovis