Murat Akova | Hacettepe University (original) (raw)
Papers by Murat Akova
Bone Marrow Transplantation, 2009
In addition to general recommendations regarding bacterial infections, this section provides spec... more In addition to general recommendations regarding bacterial infections, this section provides specific recommendations with regard to Streptococcus pneumoniae, viridans streptococci (mainly the S. mitis and S. anginosus groups), Haemophilus influenzae type b (Hib) and central lineassociated bloodstream infections (CLABSI). Recommendations regarding specific nosocomial infections, including those from Legionella species, methicillin-resistant Staphylococcus aureus, Staphylococcus species with reduced susceptibility to vancomycin, vancomycin-resistant Enterococcus and Clostridium difficile are found in the Infection Prevention and Control in Healthcare Facilities section.
![Research paper thumbnail of [Pneumonia caused by Fusobacterium necrophorum: is Lemierre syndrome still current?]](https://attachments.academia-assets.com/48099897/thumbnails/1.jpg)
](Mikrobiyoloji bülteni, 2011
Fusobacterium necrophorum is a non-spore-forming gram-negative anaerobic bacillus that may be the... more Fusobacterium necrophorum is a non-spore-forming gram-negative anaerobic bacillus that may be the causative agent of localized or severe systemic infections. Systemic infections due to F.necrophorum are known as Lemierre's syndrome, postanginal sepsis or necrobacillosis. The most common clinical course of severe infections in humans is a progressive illness from tonsillitis to septicemia in previously healthy young adults. A septic thrombophlebitis arising from the tonsillar veins and extending into the internal jugular vein leads to septicemia and septic emboli contributing to the development of necrotic abscesses especially in lungs and other tissues such as liver, bone and joints. In this case report, a previously healthy man with pneumonia and empyema due to F.necrophorum has been presented. A 22 year-old man suffering from sore throat for seven days was admitted to emergency department with ongoing fever and dysphagia for three days. On admission he was already taking amoxi...
Mikrobiyoloji bülteni, 2011
The aim of this study was to determine the in vitro activities of doripenem, imipenem, and merope... more The aim of this study was to determine the in vitro activities of doripenem, imipenem, and meropenem against clinical gram-negative isolates. A total of 596 clinical isolates were obtained from intensive care unit (ICU) and non-ICU patients in 10 centers over Turkey between September-December 2008. The origin of the isolates was patients with nosocomial pneumonia (42.4%), bloodstream infections (%40.4), and complicated intraabdominal infections (17.1%). Of the isolates, 51.8% were obtained from ICU patients. The study isolates consisted of Pseudomonas spp. in 49.8%, Enterobacteriaceae in 40.3%, and other gram-negative agents in 9.9%. The minimum inhibitory concentrations (MIC) for doripenem, imipenem and meropenem were determined for all isolates in each center using Etest® strips (AB Biodisk, Solna, Sweden). Of the isolates, 188 (31.5%) were resistant to at least one of the carbapenems. MIC50 of doripenem against Pseudomonas spp. Was 1 mg/L which was similar to that of meropenem an...
Clinical infectious diseases : an official publication of the Infectious Diseases Society of America, Jan 15, 2005
Neutropenic patients with cancer may develop several episodes of fever and infection during chemo... more Neutropenic patients with cancer may develop several episodes of fever and infection during chemotherapy-induced myeloaplasia. To identify risk factors for secondary infectious episodes among patients who responded to initial antibiotic therapy, we retrospectively analyzed 2 consecutive, prospective, randomized clinical trials performed by the International Antimicrobial Therapy Group of the European Organization for Research and Treatment of Cancer during 1991-1994. Of 1720 patients with their first episode of febrile neutropenia, 836 responded to the initial antibiotic regimen and were therefore suitable for our analysis. A secondary infection was observed in 129 (15%) of 836 patients that occurred at a median of 10 days (range, 1-28 days) after the onset of the primary febrile episode. Factors at both baseline and day 4 were analyzed. Age of >16 years (odds ratio [OR], 3.46; P<.001), acute leukemia in first induction (OR, 3.17; P<.001), presence of intravenous line (OR, ...
Medical Teacher, 2006
Professional behaviour, being one of the domains of professionalism, is an area of medical educat... more Professional behaviour, being one of the domains of professionalism, is an area of medical education that has long been of concern to medical educators. At Hacettepe University, our main goal is to have students become conscious of professional identity, values, responsibilities and the physician-patient relationship. We welcome our new students with an opening ceremony on their first day and two months later, the students start the course called &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;Health-Illness Concepts and Medical Professional Identity&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;. Students are expected to discuss the subjects given to them as scenarios or arguments. The aim of our study is to determine whether the course leads to a positive change in students&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; attitudes, indicating the attainment of those attributes that reflect professionalism. On the first and the last days of the course, a questionnaire was delivered to the students. Any positive change in preferences between the two questionnaires is identified as an achievement of that attribute. As a result we found that in all of the seven attributes there were positive changes in the students&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; attitudes. Positive changes varied from 48% to 84% and all were statistically significant. Using more interactive techniques helped the students to make larger percentage changes in their awareness of these professional attributes.
International Journal of Infectious Diseases, 2008
Objective: The purpose of this trial was to determine the spectrum of diseases with fever of unkn... more Objective: The purpose of this trial was to determine the spectrum of diseases with fever of unknown origin (FUO) in Turkey. Methods: A prospective multicenter study of 154 patients with FUO in twelve Turkish tertiarycare hospitals was conducted.
International Journal of Antimicrobial Agents, 2007
The rapid spread of acquired metallo--lactamases (MBLs) among major Gram-negative pathogens is a... more The rapid spread of acquired metallo--lactamases (MBLs) among major Gram-negative pathogens is a matter of particular concern worldwide and primarily in Europe, one of first continents where the emergence of acquired MBLs has been reported and possibly the geographical area where the increasing diversity of these enzymes and the number of bacterial species affected are most impressive. This spread has not been paralleled by accuracy/standardisation of detection methods, completeness of epidemiological knowledge or a clear understanding of what MBL production entails in terms of clinical impact, hospital infection control and antimicrobial chemotherapy. A number of European experts in the field met to review the current knowledge on this phenomenon, to point out open issues and to reinforce and relate to one another the existing activities set forth by research institutes, scientific societies and European Union-driven networks.
Clinical Microbiology and Infection, 2002
We have evaluated the in vitro activities of seven fluoroquinolones against 69 strains of Brucell... more We have evaluated the in vitro activities of seven fluoroquinolones against 69 strains of Brucella melitensis. According to their minimum inhibitory concentration for 90% growth (MIC 90 ) values, the most active agent was found to be sparfloxacin (MIC 90 0.12 mg/L) followed by levofloxacin, ciprofloxacin, ofloxacin (MIC 90 0.50 mg/L) and grepafloxacin (MIC 90 1 mg/L), gemifloxacin (MIC 90 2 mg/L) and gatifloxacin (MIC 90 4 mg/L).
Clinical Infectious Diseases, 1998
Urologia …, 2000
The purpose of this study is to evaluate the prevalence of hepatitis B virus (HBV) and hepatitis ... more The purpose of this study is to evaluate the prevalence of hepatitis B virus (HBV) and hepatitis C virus (HCV) infections and the related risk factors among urologic surgery patients and urologists. This cross-sectional, prospective study included 300 consecutive urologic ...
European Journal of Cancer, 2004
Oropharyngeal candidiasis is a frequent infection in cancer patients who receive cytotoxic drugs.... more Oropharyngeal candidiasis is a frequent infection in cancer patients who receive cytotoxic drugs. In this study, the efficacy, safety and tolerance of fluconazole and itraconazole were compared in non-neutropenic cancer patients with oropharyngeal candidiasis. Of 279 patients who were randomised between the two treatment groups, 252 patients were considered to be eligible (126 in each group). The clinical cure rate
Objective: The characteristics of infectious diseases (ID) departments including technical capaci... more Objective: The characteristics of infectious diseases (ID) departments including technical capacities, infrastructure, infection control procedures, patient types and their severity status, and antibiotic consumption habits in Turkish University hospitals were assessed in this cross-sectional point prevalence study with this questionnaries. Methods: This cross-sectional point prevalence survey was carried on a single day and two questionnaires related to patients and ID department were sent to participant centers. Nine university hospitals have joined in this project in Turkey. Results: Overall, 152 patients (72 females and 80 males) were hospitalized in these departments in the study day. Forty patients (26.3 %) were in single and 90 patients (59.2 %) were in two-bed rooms. There were gloves and antiseptics in the rooms of 131 (86 %) patients. All of the ID departments had room oxygenation systems and eight departments had a microbiology laboratory inside the clinic. All centers ha...
J Antimicrob Chemother, 2014
2 Nigro SJ, Farrugia DN, Paulsen ITet al. A novel family of genomic resistance islands, AbGRI2, c... more 2 Nigro SJ, Farrugia DN, Paulsen ITet al. A novel family of genomic resistance islands, AbGRI2, contributing to aminoglycoside resistance in Acinetobacter baumannii isolates belonging to global clone 2. J Antimicrob Chemother 2013; 68: 554-7.
Clinical Infectious Diseases, 2014
Infectious Diseases in Clinical Practice, 2012
Our study aims to determine the efficacy of infectious disease consultations and the interrelatio... more Our study aims to determine the efficacy of infectious disease consultations and the interrelations between doctors in this social laboratory. This study was conducted at 34 centers located in 22 cities across Turkey and contributed by 210 infectious disease specialists (IDSs) and 970 nonYinfectious disease specialists (NIDSs), totaling 1180 medical doctors. Infectious disease specialists and NIDSs have separately contributed by responding to questionnaires designed specifically for the consultation process. It appears that a satisfactory collaboration has been established between IDSs and NIDSs during the consultation practices. There are some discrepancies in the perceptions of some of the NIDSs. These are the evaluation of patients holistically, the expectation of NIDSs in critical infection cases to start the therapy immediately, losing the support of drug companies by NIDSs, and the restriction of NIDSs in routine medical practice. On the other hand, NIDSs seem to have real problems in the diagnosis or treatment of infectious diseases. The consultation service provided by the IDSs in Turkey is widely accepted among other clinicians and appears to be of a crucial importance.
European Journal of Clinical Microbiology & Infectious Diseases, 2014
The purpose of this study was to evaluate a new chromogenic medium, chromID OXA-48, for the isola... more The purpose of this study was to evaluate a new chromogenic medium, chromID OXA-48, for the isolation of carbapenemase-producing Enterobacteriaceae (CPE) directly from rectal swabs. chromID CARBA and chromID OXA-48 are two chromogenic media that have been commercialized for the isolation of CPE directly from clinical samples. Both media were evaluated alongside a broth enrichment method recommended by the CDC for isolation of CPE, with rectal swabs from 302 unique hospitalized patients at the Hacettepe University Hospital, Ankara, Turkey. A total of 33 patients (11 %) were found to be colonized with CPE using a combination of all methods, and all CPE produced OXA-48 carbapenemase. Klebsiella pneumoniae was by far the most dominant species of CPE and was isolated from 31 patients. Culture on chromID OXA-48 offered the highest sensitivity (75.8 %) for detection of CPE compared with the other two methods (sensitivity for both other methods was 57.6 %) and also offered the highest specificity (99.3 %). However, a combination of methods (either chromID OXA-48 plus CDC method or chromID OXA-48 plus chromID CARBA) was necessary to achieve an acceptable sensitivity (90.9 %). For isolation of CPE, in a setting where OXA-48 carbapenemase is the dominant type of carbapenemase, chromID OXA-48 is a highly useful medium but using a combination of methods is optimal for adequate detection. The combined use of two chromogenic media offered acceptable sensitivity (90.9 %) and the highest specificity (98.5 %) and also allowed for isolation of CPE within 18-20 h.
Journal of Medical Microbiology, 1991
Xanthomonas maltophilia produces two inducible P-lactamases, L 1 and L2, and resists the antimicr... more Xanthomonas maltophilia produces two inducible P-lactamases, L 1 and L2, and resists the antimicrobial activity of P-lactam antibiotics, including carbapenems. L1 is a zinc-metaloenzyme with carbapenemase activity; L2 is an unusual cephalosporinase. Mutant strains with high-and low-level constitutive expression of these enzymes were derived from three reference strains of X. maltophilia. With a single exception, the mutant strains had altered expression of both enzymes, indicating that these P-lactamases share regulatory components. The exception was a mutant strain that had low-level constitutive (basal) expression of L1 enzyme but remained inducible for L2. A parent strain with low-level Blactamase inducibility was more susceptible to penicillins, cephalosporins and carbapenems than were those in which higher levels of enzyme activity were inducible. Mutations that caused high-level constitutive P-lactamase expression increased resistance to penicillins and newer cephalosporins. P-Lactamase basal mutant strains, including the one that remained inducible for L2 enzyme, were more susceptible than inducible strains to these drugs. Organisms with inducible or high-level constitutive P-lactamase expression were equally resistant to meropenem and imipenem but basal mutant strains, including the one that remained inducible for L2 enzyme, were more susceptible to meropenem than imipenem. Minimal inhibitory concentrations of meropenem, penicillins and cephalosporins, but not imipenem, were greater on Mueller Hinton agar than on IsoSensitest or Diagnostic Sensitivity Test agars. This behaviour was independent of P-lactamase inducibility, and may reflect permeability differences between cells grown on different media.
Bone Marrow Transplantation, 2009
In addition to general recommendations regarding bacterial infections, this section provides spec... more In addition to general recommendations regarding bacterial infections, this section provides specific recommendations with regard to Streptococcus pneumoniae, viridans streptococci (mainly the S. mitis and S. anginosus groups), Haemophilus influenzae type b (Hib) and central lineassociated bloodstream infections (CLABSI). Recommendations regarding specific nosocomial infections, including those from Legionella species, methicillin-resistant Staphylococcus aureus, Staphylococcus species with reduced susceptibility to vancomycin, vancomycin-resistant Enterococcus and Clostridium difficile are found in the Infection Prevention and Control in Healthcare Facilities section.
Mikrobiyoloji bülteni, 2011
Fusobacterium necrophorum is a non-spore-forming gram-negative anaerobic bacillus that may be the... more Fusobacterium necrophorum is a non-spore-forming gram-negative anaerobic bacillus that may be the causative agent of localized or severe systemic infections. Systemic infections due to F.necrophorum are known as Lemierre's syndrome, postanginal sepsis or necrobacillosis. The most common clinical course of severe infections in humans is a progressive illness from tonsillitis to septicemia in previously healthy young adults. A septic thrombophlebitis arising from the tonsillar veins and extending into the internal jugular vein leads to septicemia and septic emboli contributing to the development of necrotic abscesses especially in lungs and other tissues such as liver, bone and joints. In this case report, a previously healthy man with pneumonia and empyema due to F.necrophorum has been presented. A 22 year-old man suffering from sore throat for seven days was admitted to emergency department with ongoing fever and dysphagia for three days. On admission he was already taking amoxi...
Mikrobiyoloji bülteni, 2011
The aim of this study was to determine the in vitro activities of doripenem, imipenem, and merope... more The aim of this study was to determine the in vitro activities of doripenem, imipenem, and meropenem against clinical gram-negative isolates. A total of 596 clinical isolates were obtained from intensive care unit (ICU) and non-ICU patients in 10 centers over Turkey between September-December 2008. The origin of the isolates was patients with nosocomial pneumonia (42.4%), bloodstream infections (%40.4), and complicated intraabdominal infections (17.1%). Of the isolates, 51.8% were obtained from ICU patients. The study isolates consisted of Pseudomonas spp. in 49.8%, Enterobacteriaceae in 40.3%, and other gram-negative agents in 9.9%. The minimum inhibitory concentrations (MIC) for doripenem, imipenem and meropenem were determined for all isolates in each center using Etest® strips (AB Biodisk, Solna, Sweden). Of the isolates, 188 (31.5%) were resistant to at least one of the carbapenems. MIC50 of doripenem against Pseudomonas spp. Was 1 mg/L which was similar to that of meropenem an...
Clinical infectious diseases : an official publication of the Infectious Diseases Society of America, Jan 15, 2005
Neutropenic patients with cancer may develop several episodes of fever and infection during chemo... more Neutropenic patients with cancer may develop several episodes of fever and infection during chemotherapy-induced myeloaplasia. To identify risk factors for secondary infectious episodes among patients who responded to initial antibiotic therapy, we retrospectively analyzed 2 consecutive, prospective, randomized clinical trials performed by the International Antimicrobial Therapy Group of the European Organization for Research and Treatment of Cancer during 1991-1994. Of 1720 patients with their first episode of febrile neutropenia, 836 responded to the initial antibiotic regimen and were therefore suitable for our analysis. A secondary infection was observed in 129 (15%) of 836 patients that occurred at a median of 10 days (range, 1-28 days) after the onset of the primary febrile episode. Factors at both baseline and day 4 were analyzed. Age of >16 years (odds ratio [OR], 3.46; P<.001), acute leukemia in first induction (OR, 3.17; P<.001), presence of intravenous line (OR, ...
Medical Teacher, 2006
Professional behaviour, being one of the domains of professionalism, is an area of medical educat... more Professional behaviour, being one of the domains of professionalism, is an area of medical education that has long been of concern to medical educators. At Hacettepe University, our main goal is to have students become conscious of professional identity, values, responsibilities and the physician-patient relationship. We welcome our new students with an opening ceremony on their first day and two months later, the students start the course called &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;Health-Illness Concepts and Medical Professional Identity&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;. Students are expected to discuss the subjects given to them as scenarios or arguments. The aim of our study is to determine whether the course leads to a positive change in students&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; attitudes, indicating the attainment of those attributes that reflect professionalism. On the first and the last days of the course, a questionnaire was delivered to the students. Any positive change in preferences between the two questionnaires is identified as an achievement of that attribute. As a result we found that in all of the seven attributes there were positive changes in the students&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; attitudes. Positive changes varied from 48% to 84% and all were statistically significant. Using more interactive techniques helped the students to make larger percentage changes in their awareness of these professional attributes.
International Journal of Infectious Diseases, 2008
Objective: The purpose of this trial was to determine the spectrum of diseases with fever of unkn... more Objective: The purpose of this trial was to determine the spectrum of diseases with fever of unknown origin (FUO) in Turkey. Methods: A prospective multicenter study of 154 patients with FUO in twelve Turkish tertiarycare hospitals was conducted.
International Journal of Antimicrobial Agents, 2007
The rapid spread of acquired metallo--lactamases (MBLs) among major Gram-negative pathogens is a... more The rapid spread of acquired metallo--lactamases (MBLs) among major Gram-negative pathogens is a matter of particular concern worldwide and primarily in Europe, one of first continents where the emergence of acquired MBLs has been reported and possibly the geographical area where the increasing diversity of these enzymes and the number of bacterial species affected are most impressive. This spread has not been paralleled by accuracy/standardisation of detection methods, completeness of epidemiological knowledge or a clear understanding of what MBL production entails in terms of clinical impact, hospital infection control and antimicrobial chemotherapy. A number of European experts in the field met to review the current knowledge on this phenomenon, to point out open issues and to reinforce and relate to one another the existing activities set forth by research institutes, scientific societies and European Union-driven networks.
Clinical Microbiology and Infection, 2002
We have evaluated the in vitro activities of seven fluoroquinolones against 69 strains of Brucell... more We have evaluated the in vitro activities of seven fluoroquinolones against 69 strains of Brucella melitensis. According to their minimum inhibitory concentration for 90% growth (MIC 90 ) values, the most active agent was found to be sparfloxacin (MIC 90 0.12 mg/L) followed by levofloxacin, ciprofloxacin, ofloxacin (MIC 90 0.50 mg/L) and grepafloxacin (MIC 90 1 mg/L), gemifloxacin (MIC 90 2 mg/L) and gatifloxacin (MIC 90 4 mg/L).
Clinical Infectious Diseases, 1998
Urologia …, 2000
The purpose of this study is to evaluate the prevalence of hepatitis B virus (HBV) and hepatitis ... more The purpose of this study is to evaluate the prevalence of hepatitis B virus (HBV) and hepatitis C virus (HCV) infections and the related risk factors among urologic surgery patients and urologists. This cross-sectional, prospective study included 300 consecutive urologic ...
European Journal of Cancer, 2004
Oropharyngeal candidiasis is a frequent infection in cancer patients who receive cytotoxic drugs.... more Oropharyngeal candidiasis is a frequent infection in cancer patients who receive cytotoxic drugs. In this study, the efficacy, safety and tolerance of fluconazole and itraconazole were compared in non-neutropenic cancer patients with oropharyngeal candidiasis. Of 279 patients who were randomised between the two treatment groups, 252 patients were considered to be eligible (126 in each group). The clinical cure rate
Objective: The characteristics of infectious diseases (ID) departments including technical capaci... more Objective: The characteristics of infectious diseases (ID) departments including technical capacities, infrastructure, infection control procedures, patient types and their severity status, and antibiotic consumption habits in Turkish University hospitals were assessed in this cross-sectional point prevalence study with this questionnaries. Methods: This cross-sectional point prevalence survey was carried on a single day and two questionnaires related to patients and ID department were sent to participant centers. Nine university hospitals have joined in this project in Turkey. Results: Overall, 152 patients (72 females and 80 males) were hospitalized in these departments in the study day. Forty patients (26.3 %) were in single and 90 patients (59.2 %) were in two-bed rooms. There were gloves and antiseptics in the rooms of 131 (86 %) patients. All of the ID departments had room oxygenation systems and eight departments had a microbiology laboratory inside the clinic. All centers ha...
J Antimicrob Chemother, 2014
2 Nigro SJ, Farrugia DN, Paulsen ITet al. A novel family of genomic resistance islands, AbGRI2, c... more 2 Nigro SJ, Farrugia DN, Paulsen ITet al. A novel family of genomic resistance islands, AbGRI2, contributing to aminoglycoside resistance in Acinetobacter baumannii isolates belonging to global clone 2. J Antimicrob Chemother 2013; 68: 554-7.
Clinical Infectious Diseases, 2014
Infectious Diseases in Clinical Practice, 2012
Our study aims to determine the efficacy of infectious disease consultations and the interrelatio... more Our study aims to determine the efficacy of infectious disease consultations and the interrelations between doctors in this social laboratory. This study was conducted at 34 centers located in 22 cities across Turkey and contributed by 210 infectious disease specialists (IDSs) and 970 nonYinfectious disease specialists (NIDSs), totaling 1180 medical doctors. Infectious disease specialists and NIDSs have separately contributed by responding to questionnaires designed specifically for the consultation process. It appears that a satisfactory collaboration has been established between IDSs and NIDSs during the consultation practices. There are some discrepancies in the perceptions of some of the NIDSs. These are the evaluation of patients holistically, the expectation of NIDSs in critical infection cases to start the therapy immediately, losing the support of drug companies by NIDSs, and the restriction of NIDSs in routine medical practice. On the other hand, NIDSs seem to have real problems in the diagnosis or treatment of infectious diseases. The consultation service provided by the IDSs in Turkey is widely accepted among other clinicians and appears to be of a crucial importance.
European Journal of Clinical Microbiology & Infectious Diseases, 2014
The purpose of this study was to evaluate a new chromogenic medium, chromID OXA-48, for the isola... more The purpose of this study was to evaluate a new chromogenic medium, chromID OXA-48, for the isolation of carbapenemase-producing Enterobacteriaceae (CPE) directly from rectal swabs. chromID CARBA and chromID OXA-48 are two chromogenic media that have been commercialized for the isolation of CPE directly from clinical samples. Both media were evaluated alongside a broth enrichment method recommended by the CDC for isolation of CPE, with rectal swabs from 302 unique hospitalized patients at the Hacettepe University Hospital, Ankara, Turkey. A total of 33 patients (11 %) were found to be colonized with CPE using a combination of all methods, and all CPE produced OXA-48 carbapenemase. Klebsiella pneumoniae was by far the most dominant species of CPE and was isolated from 31 patients. Culture on chromID OXA-48 offered the highest sensitivity (75.8 %) for detection of CPE compared with the other two methods (sensitivity for both other methods was 57.6 %) and also offered the highest specificity (99.3 %). However, a combination of methods (either chromID OXA-48 plus CDC method or chromID OXA-48 plus chromID CARBA) was necessary to achieve an acceptable sensitivity (90.9 %). For isolation of CPE, in a setting where OXA-48 carbapenemase is the dominant type of carbapenemase, chromID OXA-48 is a highly useful medium but using a combination of methods is optimal for adequate detection. The combined use of two chromogenic media offered acceptable sensitivity (90.9 %) and the highest specificity (98.5 %) and also allowed for isolation of CPE within 18-20 h.
Journal of Medical Microbiology, 1991
Xanthomonas maltophilia produces two inducible P-lactamases, L 1 and L2, and resists the antimicr... more Xanthomonas maltophilia produces two inducible P-lactamases, L 1 and L2, and resists the antimicrobial activity of P-lactam antibiotics, including carbapenems. L1 is a zinc-metaloenzyme with carbapenemase activity; L2 is an unusual cephalosporinase. Mutant strains with high-and low-level constitutive expression of these enzymes were derived from three reference strains of X. maltophilia. With a single exception, the mutant strains had altered expression of both enzymes, indicating that these P-lactamases share regulatory components. The exception was a mutant strain that had low-level constitutive (basal) expression of L1 enzyme but remained inducible for L2. A parent strain with low-level Blactamase inducibility was more susceptible to penicillins, cephalosporins and carbapenems than were those in which higher levels of enzyme activity were inducible. Mutations that caused high-level constitutive P-lactamase expression increased resistance to penicillins and newer cephalosporins. P-Lactamase basal mutant strains, including the one that remained inducible for L2 enzyme, were more susceptible than inducible strains to these drugs. Organisms with inducible or high-level constitutive P-lactamase expression were equally resistant to meropenem and imipenem but basal mutant strains, including the one that remained inducible for L2 enzyme, were more susceptible to meropenem than imipenem. Minimal inhibitory concentrations of meropenem, penicillins and cephalosporins, but not imipenem, were greater on Mueller Hinton agar than on IsoSensitest or Diagnostic Sensitivity Test agars. This behaviour was independent of P-lactamase inducibility, and may reflect permeability differences between cells grown on different media.