الفهرس 
contentsOnly 14 pages are availabe for public view
 |  | from | 207 |  |  |
| | | from | 207 | | |
Abstract
Mpneumoniae has remained a consistent and significant cause of TI since its isolation in 1944. It is responsible for only a small proportion of UR TIs in children less than 14 years old, but is one of the most common aetiological agents ofLRTIs among adults younger than 30 years old. Although only 3- 10 of cases infected with Mpneumoniae actually develop pneumonia, the organism is a major cause of primary atypical pneumonia (Walking pneumonia). Mpneumoniae also causes acute bronchitis, pharyngitis and occasionally bronchiolitis. Secondary pulmonary and extrapulmonary complications, including neurological abnormalities have also been reported. Like other organisms causing RTIs,M.pneumoniae is transmitted via close contact by airborne transfer and is an extracellular pathogen that adheres to the ciliary tracheal epithelium by means of specialized terminal protein attachment factors, where ciliostasis and then destruction of superficial layer of epithelial cells occur, due to the release of H202 and superoxide anion. Infection caused by M.pneumoniae is endemic and occurs world wide throughout the year with predilection for the colder months and epidemic peaks have also been observed almost every 4 years with infection rates reaching up to 35. It is estimated to cause about 20 of pneumonias in the general population and up to 50 of pneumonias in closed population. The laboratory diagnosis of Mpneumoniae infection is based either on the direct isolation of organism by culture which is insensitive, difficult to perform and time consuming or its Ag detection in respiratory exudates ~umrnary ctllU \.,..UI1C1UblUl1 l.JJ. using immunological (EIA, IF) or molecular genetic techniques (DNA ~robe, PCR). The routine diagnosis is done indirectly by the detection of its !pecific antibodies in serum using serological techniques (CFT, EIA, IHA, Immunoblotting, particle agglutination). Erythromycin and tetracycline are the drugs of choice in the !reatment of Mpneumoniae infection. ” This work aimed to study the association of M.pneumoniae with LRTI in Yemen, the efficacy of different laboratory diagnostic techniques including direct and indirect methods and finally the susceptibility of Mpneumoniae to some antibiotics. The present study was carried out during a six months period from October 97 to March 98. It included 405 outpatient and inpatient cases with LRTI (217 males and 188 females), admitted to AI-Kuwait University Hospital, Al-Jomhory Government Hospital, National TB Center and Central Health Laboratory in the city of Sana’ a, Yemen. Their age ranged from 10 to 60 years. Out of them 141 cases were clinically and radiographically diagnosed as lobar pneumonia, 77 as suspected TB, 57 as bronchial asthma, 54 as COPD, 52 as bronchitis and finally 24 as bronchopneumonia. A detailed history was taken from all cases, including name, age, sex, onset of illness, presenting symptoms and signs, antibiotic therapy, predisposing factors, relevant history of respiratory diseases, laboratory and clinical diagnosis. Sputum and blood samples were collected from each studied case: 1. Sputum: This was transported to the laboratory as soon as possible in a sterile screw-capped container, then homogenized with an equal volume of lOmM dithiotreitol solution and divided into 2 protions. 11 . The first portion was directly inoculated into mycoplasma diphasic medium, incubated with 5-10 CO2 at 35°C for up to 4 weeks and inspected daily for turbidity or colour change. A slight gradual shift to acidic pH in the medium (violet-green) without gross turbidity after 7 days incubation suggested a true positive culture. Subculture onto mycoplasma agar medium was then done to obtain the typical colonies (fried egg) which were definitively confirmed by haemolysis test. Antibiotic susceptibility test was perfonned for some isolates using different antibiotic powders to determine the MIC by the macro broth dilution technique. . The other portion was used for the detection of Mpneumoniae antigen after pretreatment with an equal volume of2.5 skim milk buffer using an ELA technique. 2. Blood: Five ml of blood were taken aseptically by venipuncture and after complete coagulation, the serum was separated and stored at -20°C until tested for both M.pneumoniae specific IgM and IgG antibodies using a commercially available EIA kit. Tile results of tile present study showed tltat: I- Out of the 405 studied cases with LRTIs, Mpneumoniae was isolated trom the sputum of 39(9.6) cases, its Ag was detected in 59(14.6) cases and its both specific IgM and IgG antibodies were detected in the sera of 84(20.7) and 30(7.4) cases respectively. 2- School children were found more affected with Mpneumoniae by all the different diagnostic methods, followed by young adults and then adults. The association was statistically significant except between IgG positive cases and these age groups. J. Males were found more affected than females with M.pneumoniae by culture, Ag-EIA and IgG-EIA. This association was statistically significant, except between culture positive cases and both sexes. On the other hand females were significantly more affected than males regarding IgM - EIA. ~. M.pneumoniae was positive by culture and Ag-EIA early in the study period (October), while IgM and IgG-EIAs were still negative and started to increase gradually throughout the study period reaching their peak in December and Febnmry. In contrast culture and Ag-EIA began to decline late in the study period (February) and became negative at the end of study period (March), whereas IgM and IgG, EIAs remained positive. This association was highly statistically significant. 5. Outpatients were statistically more affected than inpatients with Mpneumoniae by culture and Ag-EIA, whereas nearly similar positive results were found between both groups regarding the IgM and IgG EIAs with no statistical significance. 6- The most frequent underlying clinical condition among culture and Ag positive cases was bronchial asthma followed by lobar pneumonia and bronchopneumonia, whereas, the main frequent clinical condition among IgM and IgG positive cases was bronchopneumonia, followed by bronchitis and lobar pneumonia. 7- The main present symptom among M.pneumoniae positive cases was cough, followed by dyspnoea and chest pain. 8- The main pulmonary complication among the Mpneumoniae positive cases was respiratory distress, followed by pleural effusion and lung abscess. ~. There was no statistical significant association between Ag, IgM and IgG positive cases and the different crowding index patterns, except between culture positive cases and this crowding index. 10- There was no statistical significant association between culture, Ag and IgM positive cases and the smoking habit, except between IgG positive cases and this habit. 1]- There was a statistical significant association between culture and Ag positive cases and the gat chewing habit, whereas, there was no statistical significant association between IgM and IgG positive cases and this habit. 12-Recent family history ofRTI seemed to play a role in the appearance of Mpneumoniae. This association was not statistically significant, except between IgM positive cases and the family history ofRTI. 13- There was a statistical significant association between IgM and IgG positive cases and the pre-antibiotic administration, whereas, there was no statistical significant association between culture and Ag positive cases and the pre-antibiotic administration. l4-The present study failed to reveal any statistical significant correlation between the culture and serological results, but there was a high statistically significant correlation between the culture and Ag results. l5-Ag-EIA was highly sensitive, in contrast, IgM and IgG-EIAs were’of low sensitivity when compared with culture, being 100, 28.2 and 5.1 respectively.