1/5. levofloxacin treatment failure in a patient with fluoroquinolone-resistant streptococcus pneumoniae pneumonia.The frequency of fluoroquinolone-resistant streptococcus pneumoniae has increased as fluoroquinolone administration for treatment of respiratory tract infections has increased. levofloxacin treatment failed in a patient who had pneumococcal pneumonia and had received three previous courses of levofloxacin therapy. Susceptibility testing revealed high-level resistance to levofloxacin (minimum inhibitory concentration [MIC] > 32 microg/ml), and cross-resistance to moxifloxacin (MIC 4 microg/ml), trovafloxacin (6 microg/ml), and gatifloxacin (12 microg/ml). Sequencing of the quinolone-resistance determining region revealed a mutation of serine-81 to phenylalanine (Ser81-->Phe) in the gyrA region of dna gyrase and a Ser79-->Phe mutation in the parC region of topoisomerase IV The patient was treated successfully with intravenous ceftriaxone followed by oral cefprozil. Clinicians must be aware of local resistance patterns and the potential for fluoroquinolone treatment failures in patients with infections caused by S. pneumoniae.- - - - - - - - - - ranking = 1keywords = treatment failure (Clic here for more details about this article) |
2/5. ciprofloxacin treatment failure in a patient with resistant streptococcus pneumoniae infection following prior ciprofloxacin therapy.Reported here is the case of a patient with underlying chronic obstructive pulmonary disease (COPD) in whom ciprofloxacin treatment of a lower respiratory tract infection failed subsequent to ciprofloxacin treatment of an exacerbation of COPD several weeks earlier. During the second course of ciprofloxacin therapy, the patient's condition continued to deteriorate, and she was admitted to the intensive care unit. Bilateral pneumonia was diagnosed. streptococcus pneumoniae, serotype 11A, resistant to ciprofloxacin was isolated from the sputum. Sequencing revealed a S79F mutation in parC and there was evidence of an efflux pump. The patient improved rapidly after administration of azithromycin and ampicillin/sulbactam. This report of treatment failure due to ciprofloxacin-resistant streptococcus pneumoniae shows that fluoroquinolones should be avoided when treating patients who have recently received this class of antibiotics.- - - - - - - - - - ranking = 1keywords = treatment failure (Clic here for more details about this article) |
3/5. Failure of levofloxacin treatment in community-acquired pneumococcal pneumonia.BACKGROUND: streptococcus pneumoniae is the leading cause of community-acquired pneumonia (CAP). High global incidence of macrolide and penicillin resistance has been reported, whereas fluoroquinolone resistance is uncommon. Current guidelines for suspected CAP in patients with co-morbidity factors and recent antibiotic therapy recommend initial empiric therapy using one fluoroquinolone or one macrolide associated to other drugs (amoxicillin, amoxicillin/clavulanate, broad-spectrum cephalosporins). Resistance to fluoroquinolones is determined by efflux mechanisms and/or mutations in the parC and parE genes coding for topoisomerase IV and/or gyrA and gyrB genes coding for dna gyrase. No clinical cases due to fluoroquinolone-resistant S. pneumoniae strains have been yet reported from italy. CASE PRESENTATION: A 72-year-old patient with long history of chronic obstructive pulmonary disease and multiple fluoroquinolone treatments for recurrent lower respiratory tract infections developed fever, increased sputum production, and dyspnea. He was treated with oral levofloxacin (500 mg bid). Three days later, because of acute respiratory insufficiency, the patient was hospitalized. levofloxacin treatment was supplemented with piperacillin/tazobactam. Microbiological tests detected a S. pneumoniae strain intermediate to penicillin (MIC, 1 mg/L) and resistant to macrolides (MIC >256 mg/L) and fluoroquinolones (MIC >32 mg/L). Point mutations were detected in gyrA (Ser81-Phe), parE (Ile460-Val), and parC gene (Ser79-Phe; Lys137-Asn). Complete clinical response followed treatment with piperacillin/tazobactam. CONCLUSION: This is the first Italian case of community-acquired pneumonia due to a fluoroquinolone-resistant S. pneumoniae isolate where treatment failure of levofloxacin was documented. Molecular analysis showed a group of mutations that have not yet been reported from italy and has been detected only twice in europe. Treatment with piperacillin/tazobactam appears an effective means to inhibit fluoroquinolone-resistant strains of S. pneumoniae causing community-acquired pneumonia in seriously ill patients.- - - - - - - - - - ranking = 0.2keywords = treatment failure (Clic here for more details about this article) |
4/5. minocycline treatment failure in pneumonia caused by minocycline-sensitive streptococcus pneumoniae.A previously healthy 23-year-old white woman had fulminant pneumococcal pneumonia complicated by empyema and bilateral pneumothoraces. Despite early treatment with the recommended doses of minocycline, the disease progressed. The S pneumoniae isolate was resistant to a 30microgram tetracycline disk and showed an MIC of 3.13microgram/ml for minocycline and 12.5 microgram/ml for tetracycline; these levels are considered by the manufacturer to indicate sensitivity to minocycline and intermediate sensitivity to tetracycline. The tetracyclines, including minocycline, should not be used to treat bacterial pneumonia since resistant strains of pneumococci are not uncommon and inffective treatment can lead to rapid progression of the infection. This case suggests that the levels of minocycline considered to indicate sensitivity in vitro be reassessed.- - - - - - - - - - ranking = 0.8keywords = treatment failure (Clic here for more details about this article) |
5/5. Failure of pristinamycin treatment in a case of pneumonia caused by a streptogramins B-type resistant pneumococcus.We report a failure of pristinamycin treatment in a case of pneumonia caused by streptogramins B-type resistant pneumococcus. We suggest that (i) streptogramins therapy should be avoided, if a previous treatment failure has been observed with a macrolide and/or if the antibiogram shows the MLS(B) co-resistance phenotype, and (ii) beta-lactams should remain the first-line antibiotics used for treatment of pneumococcal respiratory infections.- - - - - - - - - - ranking = 0.2keywords = treatment failure (Clic here for more details about this article) |