Comparison of common detection methods for chlamydia trachomatis and genital mycoplasmas in cervical infection

Genitourinary infections are caused by a large number of diverse microbial agents, in many women with cervicitis, these agents are not detected, even when highly sensitive diagnostic tests are performed. Less urbanized communities have a proportionally higher incidence of urethritis and cervicitis, caused by Chlamydia trachomatic [C. trachomatis]. In addition, mycoplasmas commonly colonize the genital tracts of men and women, and the ability of some species to cause non-gonococcal urethritis and cervicitis has been well established. To detect the prevalence of C. trachomatis, M. hominis and U. urealyticum in cases of cervicitis and to compare different laboratory methods for the diagnosis of these organisms. A total of 50 women suffering from cervicitis were enrolled in this work. To determine the causative agents, PCR, detection of mycoplasmas [Using Mycoplasma IST2 kit] and direct immunofluorescence assay for Chlamydia trachomatis were used. U. urealyticum was isolated from 18 cases [36%], while M. hominis was isolated only from 2 cases [4%]. Besides, 10 cases [20%] were infected by both organisms. U. urealyticum was detected in 5 cases [10%] by multiplex PCR and in 8 cases [16%] by monoplex PCR. M. hominis was detected in 10 cases [20%] both by multiplex as well as by monoplex PCR. C. trachomatis was detected in 3 samples with counts of 16.760, 28.2 and 10 DNA copies/ml using Real Time PCR. However, it was not detected by direct immunofluorescence assay in any of the samples. Mycoplasma IST2 culture was more sensitive for the detection of genital mycoplasmas and Real Time PCR was a better diagnostic test for the detection of C. trachomatis

Demographic features and antimicrobial susceptibility of acinetobacter species isolated from intensive care units

Background: The rising incidence .of acinetobacter infection in the intensive care units [1CUs] causes a great concern to all clinicians worldwide. Acinetobacter species have an extraordinary ability to develop resistance to multiple classes of antibiotics, which limit array of the therapeutic options. Objective is to determine the prevalence of acinetobacter infection in ICUs of Kasr EL-Aini Hospital, its demographic features, speciation and antibiotic sensitivity pattern

Methods: 166 specimens, collected from 140 infected patients in ICUs, were subjected to direct microscopic examination and culture on blood, MacConkey and Herellea media. Microbact 12A [12E] Gram-negative identification system was used. Susceptibility patterns were done by Modified Kirby Bauer disc-diffusion methods

Results: 30/140 infected patients [21.4 %] were found to be infected with acinetobacter spp. Acinetobacter was responsible for 26.3% of LRTls, 20% of wound infections and 16.2% of UTls. A. baumannii was the most predominant species [93.3%]. Prolonged stay in ICU [p=0.03] and stroke [p=0.005] were significantly associated with acinetobacter infections. The most effective antibiotics were cefoperazone/sulbactam [40%], imipenem [36.7%] and amikaein [30%]

Conclusion: 21.4% of the studied patients suffered from acinetobacter infections. Invasive procedures, prolonged stay in ICU as well as previous antibiotic treatment are associated with higher rate of infection. Eradication of acinetobacter spp. requires adherence to good infection control practices and prudent antibiotic use

Role of fatty acids as environmental regulator on Proteus mirabilis swarming and biolfilm formation in catheterassociated urinary tract infection

Proteus mirabilis is a common cause of Catheter-Associated Urinary Tract Infection [CAUTI]. Aim of the Work: This study evaluates the effect of addition of stearic, plamitic and myristic acids, to Luria Bertani [LB] culture medium on swarming, biofilm formation and exopolysaccharide [EPS] production. Thirty clinical isolates of P. mirabilis were obtained from 300 urine samples collected from catheterized Egyptian patients. Myristic [0.01%] and palmitic [0.02%] acids could inhibit swarming and EPS production significantly. Myristic acid is the only one that significantly inhibited biofilm formation, but lowering the concentration increased biofilm formation insignificantly. Also myristic acid inhibited swarming and EPS production in a dose-dependent manner. Palmitic acid had no significant effect on biofilm formation. On the other hand, stearic acid [0.005%] significantly enhanced swarming and EPS production with no significant effect on biofilm formation. The inhibitory effect of these fatty acids enhances their practical application as inexpensive tools for development of novel catheters, which could be more resistant to P. mirabilis CAUTIs

Biofilm and device-associated infections

Medical devices-associated infections continue to be a significant source of morbidity and mortality, and lead to increased medical expenses by prolonging hospitalization. These infections are most commonly caused by biofilm producing organisms. Study microbial biofilm in different medical devices, their association with infections and their antimicrobial resistance. Hundred and three egyptian patients with different indwelling medical devices were studied to isolate and to identify the organisms present on the device surfaces. Biofilm production was tested qualitatively using tube and plate adherence methods and semi-quantitatively by measuring optical density of adherence by spectrophotometer. Antimicrobial resistance was detected using Calgary's device. The presence of biofilm, on some of the devices, was confirmed using scanning electron microscopy. Different species were isolated from 65.1% of the studied devices. Associated infections, detected by blood and urine cultures, were 48% and 61%, respectively. Biofilm production by the isolates showed that 11.9% were weak, 17.9% were strong and 70.2% were non producers. Staphylococcus spp. represented 40% of biofilm producing organisms. Antimicrobial resistance showed statistically significant difference between planktonic and biofilm cells as measured by Minimum Inhibitory Concentration [MIC] and Minimum Biofilm Eradication Concentration [MBEC]. There were a significant percentage of organisms able to grow within biofilm on indwelling medical device surfaces and considered as a source of infection. Both plate adherence and spectrophotometric methods are reliable tests, any of them can be used to diagnose biofilm formation. Spectrophotometric method is the most reliable test to differentiate between weak and strong biofilm producers. Biofilm producing isolates were highly resistant to antimicrobials in comparison to their planktonic counterparts

Prevalence of extended spectrum beta lactamase producers in an Egyptian critical care center

To determine the existence of extended spectrum beta lactamase [ESBL] producing Gram negative bacilli [GNB], in an Egyptian critical care center [CCC], we conducted a study over a period of 14 months at Kasr El Aini hospital, Cairo University. We collected 340 samples from health care workers [HCWs], and from 50 patients who acquired infections during hospitalization. Susceptibility of all isolated GNB was done to cephalosporin's [e.g. ceftazidime, cefotaxime], aztreonam, aminoglycosides [e.g. amikacin, gentamycin, and tobramycin], ciprofloxacin, imipenem, piperacillin and other beta lactamase inhibitors. Out of 176 isolated GNB, 106 isolates [60.2%] were confirmed as ESBL producers, mostly Escherichia coli [E. coli, 34%] followed by Klebsiella species [spp.] [30.2%] and Pseudomonas spp. [24.5%]. The predominant hospital acquired infection was respiratory tract infection [RTI] [60.2%] followed by urinary tract infection [UTI] [15.9%]. ESBL producing E. coli were responsible for 23.6% of hospital acquired RTI followed by ESBL producing Pseudomonas spp. [21.7%] and ESBL producing Klebsiella spp. [15.1%]. On the other hand, ESBL producing E. coli and Klebsiella spp. were equally responsible for hospital acquired UTI. 80-90% of these ESBL producing GNB were sensitive to imipenem and 70-90% was sensitive to piperacillin/tazobactam. ESBL producing GNB were isolated from hands of HCWs. Plasmid profile analysis demonstrated that hands of HCWs play an important role in spread of ESBL producing GNB among patients. In conclusion, ESBL producing GNB exist in this Egyptian CCC [106/340, 31.2%]; and rational antibiotic guidelines are mandatory to minimize the problem along with infection control practices. Incorporating microbial genetic typing in infection control program is recommended

Comparison of different methods to diagnose pneumocystis jiroveci pneumonia in children with haematological malignancies

Giemsa stain and PCR [single and nested PCR] were compared to a direct immunofluorescence assay [IFA] for the detection of Pneumocystis jiroveci in immuno-compromised patients with haematological malignancies, suspected of having P. jiroveci pneumonia. A total of 50 specimens [3 bronchoalveolar lavages [BAL], 16 sputum samples and 31 nasopharyngeal aspirate samples] were obtained from the Paediatric Oncology Unit of Kasr El-Aini Oncology Centre, Faculty of Medicine, Cairo University. Direct immunofluorescence [the gold standard] could detect 4 positive cases. Giemsa stain could only detect one positive case, being 25% sensitive and 100% specific. Single PCR could detect 3 positive cases, being 75% sensitive and 100% specific. Nested PCR could detect 36 positive cases, being 100% sensitive and 19.2% specific. We conclude that whenever possible, BAL samples should be obtained, for the diagnosis of P. jiroveci pneumonia [PJP]. Diagnosis of PJP should best be performed by IF or single PCR, especially if non-invasive samples are used. Nested PCR is recommended for detection of P. jiroveci in all immunosuppressed asymptomatic patients to identify a group of patients at high risk of developing PJP in the future, for whom proper chemoprophylaxis against P. jiroveci may be beneficial