RESUMO
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
RESUMO
Background: Pseudomonas aeruginosa [P. aeruginosa] is a leading cause of nosocomial infections, including pneumonia, urinary tract infections, and bacteremia and it is highly resistant to many antibiotics by many different mechanisms, including beta-lactamases' production, specially class D OXA-beta-lactamases
Aim of work: The aim of this study was to determine the prevalence of OXA- beta-lactamases among extended-spectrumcephalosporin [ESC] non- susceptible P. aeruginosa isolates
Materials and Methods: Forty four ESC non- susceptible P. aeruginosa isolates were collected from a large teaching hospital , they were considered ESC non- susceptible if they were resistant or intermediately sensitive to one or more of ESC indicator antibiotics [ceftazidime, cefotaxime, ceftriaxone and cefepime ] and aztreonam. They were examined for the presence of genes coding for OXA-group I, II and III using PCR based techniques and all isolates harboring OXA-group I genes were subsequently subjected to digestion by a group of restriction endonucleases to determine the OXA-group I type derivative of the isolates
Results: Twenty-five isolates [56.8%] were found to harbour OXA-type enzymes. Seventeen were positive for OXA-group I and 4 were positive for OXA-group III. In addition, four isolates [16%] harboured two different OXA-type enzymes. Almost all isolates of OXA-group I were non-susceptible to ceftazidime and susceptible to cefepime while all OXA-group III isolates were susceptible to ceftazidime and most of them were non-susceptible to cefepime