Susceptibility to Teicoplanin and Daptomycin among Coagulase-Negative Staphylococci Isolated from Bloodstream Infections in Patients with Hematological Malignancies

Introduction: Recently, a decreased susceptibility to teicoplanin has been observed among coagulase-negative staphylococci (CNS) isolated from bloodstream infections in patients with hematological malignancies. In this study, we aimed to determine the minimum inhibitory concentrations (MIC) of teicoplanin, which is frequently used in the empirical treatment, and of a new agent, daptomycin, against CNS isolated from bloodstream infections. Materials and Methods: The study was performed on CNS strains isolated from bloodstream infections of patients with hematological malignancies during the period 2009-2011. Susceptibility to oxacillin was tested by disk diffusion method. Daptomycin and teicoplanin MIC were determined using the E-test method. Results: A total of 179 CNS strains causing bloodstream infections were studied. Among them, S. epidermidis (36.3%) and S. haemolyticus (35.2%) were the most frequent CNS species. The oxacillin resistance rate was found statistically higher among S. haemolyticus (61%) strains than among S. epidermidis (32%) (p= 0.001). Although teicoplanin and daptomycin resistance was not detected among the CNS isolates, two (1.1%) of the isolates demonstrated intermediate susceptibility to teicoplanin. Conclusions: S. haemolyticus and S. epidermidis were the major causes of bloodstream infections in patients with hematological malignancies. Oxacillin resistance was more frequent among S. haemolyticus isolates. Teicoplanin resistance was not detected among the CNS isolates. However, because two of the isolates demonstrated decreased susceptibility to teicoplanin, resistance rates to teicoplanin should be closely monitored. Daptomycin was found to be effective against both oxacillin-resistant and teicoplanin-intermediate CNS isolates

Demonstration of Transmission of an Acinetobacter baumannii Outbreak Between Intensive Care Units Using AP-PCR Method

Introduction: In recent years, multidrug-resistant Acinetobacter baumannii has become more prevalent. Patients, especially in the intensive care units (ICU), may be colonized in a very short period, and then they develop a severe infection with a high mortality rate, such as bacteremia, pneumonia, surgical site infections. The aim of our study was to analyze the A. baumannii outbreak using Arbitrarily Primed-Polymerase Chain Reaction (AP-PCR) method which shows transmission between ICUs. Materials and Methods: Health care associated infections (HAI) in our ICUs are followed by active prospective surveillance. The diagnosis of HAI was made according to Centers for Disease Control and Prevention (CDC) criteria. An outbreak investigation was started upon clustering in A. baumannii infections by Infection Control Committee. In the microbiological part of the outbreak investigation, a molecular analysis, AP-PCR method, was used to show a clonal relationship among the strains. The isolated strains was stored in -80°C in microbanks until the study. Results: At fi rst, an outbreak that started from a patient who died due to A. baumannii infection and included 8 patients was detected in the surgical ICU between 17th August 2013 to 18th October 2013. In this period, two patients in the surgical ICU were transferred to the anesthesiology ICU. After the transfer of the patients (13 September 2013), an outbreak occurred which included 12 patients in the anesthesiology ICU. Mainly two A. baumannii clones (A and B) were described by AP-PCR method, and transmission from the patients who transferred from surgical ICU was demonstrated. Conclusion: In this study, an outbreak due to two clones of A. baumannii was shown using clinical data and molecular investigation of isolates in two different ICUs (surgical ICU and anesthesiology ICU). Patient transfer between the units can cause outbreaks, therefore, implementation of infection control measures are important on admission. The outbreak ended with the collaboration of both surgical and anesthesiology ICU directors and employees. Molecular analysis is seen as an important method to show presence of an epidemic and provides a valuable data discovering of the source in hospital setting

The Use of Daptomycin and Quinolones Combination in Staphylococcus aureus Bacteremia: An In Vitro Synergistic Study

Introduction: Daptomycin, a novel lipopeptide antibiotic, has been introduced recently to clinical use in our country. It is approved for the treatment of complicated skin and soft tissue infections caused by gram-positive microorganisms, Staphylococcus aureus bacteremia, and right-sided endocarditis due to methicillin-resistant S. aureus (MRSA) and methicillin-sensitive S. aureus (MSSA). Its interaction with other therapeutic agents is not well studied. Although there are several studies about the combination of daptomycin with other groups of antibiotics, particularly with beta-lactams, to the best of our knowledge, there has been no study regarding daptomycin and quinolones combination therapy. In this respect, the interactions between daptomycin and quinolones (levofloxacin, ciprofloxacin) were studied in vitro. Materials and Methods: The study was held in Gazi University School of Medicine, Infectious Diseases and Clinic Microbiology Laboratory, between July 2006 and December 2009. In vitro susceptibilities and synergistic activities of daptomycin, levofloxacin and ciprofloxacin were investigated using E-test method in 20 MSSA and 20 MRSA consecutive isolates, which were identified as a cause of nosocomial bloodstream infection. Results: Only one isolate from each patient was included in the study. Fractional inhibitory concentration (FIC) index values were calculated and classified as synergistic (FIC 4). All isolates were susceptible to daptomycin. Although there was no resistance to levofloxacin and ciprofloxacin in MSSA strains, 85% resistance was determined in MRSA strains to both antibiotics. According to FIC index values, neither synergistic nor antagonistic activity between daptomycin-levofloxacin or daptomycin-ciprofloxacin was observed. Conclusion: Although there is no synergistic activity between daptomycin and quinolones against S. aureus isolates, no antagonistic activity was detected either. Even though there are no data about the clinical use of these combinations, it is thought that these drugs can be used in combination for the treatment of selected cases

[A rare and mortal infection agent in patients with hematological malignancies: Saprochaete capitata].

Saprochaete capitata (formerly known as Geotrichum capitatum and Blastoschizomyces capitatus) is a rare invasive fungal agent that may lead to mortal clinical course in patients with hematological malignancies. This agent can be colonized in skin, lungs and intestines, and it can cause major opportunistic infections. Invasive systemic infections due to S.capitata have been reported in immunosuppressed patients. In this report, two patients with invasive S.capitata infections detected during the course of persistent neutropenic fever in acute leukemia, were presented. In both cases empirical caspofungin was added to the treatment, as no response was obtained by board-spectrum antibacterial therapy in neutropenic fever. In the first patient, there were no significant findings except the chronic inflammation observed in the biopsies which was performed for the symptoms of lymphadenitis, myositis, and hepatosplenic candidiasis. While persistent fever was on going, S.capitata was isolated from the blood and catheter cultures. There was no response after catheter removing and the introduction of amphotericin B and voriconazole therapy, therefore allogeneic stem cell transplantation plan for the second time for bone marrow aplasia was taken an earlier time. However, the patient died due to progressive pericardial and pleural effusion and multiorgan failure, although an afebrile process after stem cell transplantation could be obtained. Similarly the second patient had persistent fever despite empirical caspofungin treatment. The additional symptoms of diarrhea, abdominal pain and subileus have indicated an intraabdominal infection. During the follow up, S.capitata was isolated from the blood and catheter cultures. Catheter was removed and amphotericin B was initiated. No response was obtained, and voriconazole was added to treatment. Despite of an afebrile and culture-negative period, the patient died as a result of Acinetobacter sepsis and multiorgan failure. Minimal inhibitory concentration values for both of the Saprochete strains were found as 0.25 µg/ml for amfoterisin B, 1 µg/ml for flukonazol, 0.125 µg/ml for vorikonazol and 0.25 µg/ml for itrakonazol. Virulence model was created by injecting the isolates to the Galleria mellonella larvae, and the life cycle of the larvae were determined. The observation revealed that the infected larvae began to die on the second day and there was no live larvae remained on the eleventh day. In conclusion, S.capitata should be considered as an infection agent with high mortality risk in the neutropenic patients with hematologic malignancies, especially in the presence of persistent fever during the use of caspofungin

A proven case of cutaneous rhizopus infection presenting with severe limb pain very soon after induction treatment in a patient with acute lymphoblastic leukemia.

Objective and Importance. Invasive mucormycosis may complicate the course of patients with hematologic malignancies and has a very high mortality rate. Early diagnosis and aggressive approach combined with surgical and medical treatment have paramount importance for cure. Clinical Presentation. We report here a case of a patient with acute lymphoblastic leukemia presenting with a subcutaneous mass lesion which was sampled by an ultrasound guided needle biopsy. The pathology showed microorganisms with aseptate hyphae with wide, irregular walls and more or less branching with highly vertical angles which suggested a mold infection. The specimen was also cultured where Rhizopus spp. grew. Conclusion. Posaconazole 200 mg QID was commenced. She recovered from neutropenia and pain on day 20 of treatment. After 4 courses of hyper-CVAD chemotherapy, the remaining soft tissue mass was removed surgically and she underwent allogeneic HSCT from a full matched sibling donor under secondary prophylaxis

A prospective, multi-center study: Factors related to the management of diabetic foot infections

The Turkish Association of Clinical Microbiology and Infectious Diseases, Diabetic Foot Infections Working Group conducted a prospective study to determine the factors affecting the outcomes of diabetic foot infections. A total of 96 patients were enrolled in the study. Microbiological assessment was performed in 86 patients. A total of 115 causative bacteria were isolated from 71 patients. The most frequently isolated bacterial species was Pseudomonas aeruginosa (n = 21, 18.3%). Among cases with bacterial growth, 37 patients (43%) were infected with 38 (33%) antibiotic-resistant bacteria. The mean (+/- SD) antibiotics cost was 2,220.42 (+/- 994.59) USD in cases infected with resistant bacteria, while it was 1,206.60 (+/- 1,160.6) USD in patients infected with susceptible bacteria (p 4.5 cm(2) (p = 0.041, OR = 2.8); and that related to the failure of the treatment was the growth of resistant bacteria (p = 0.016, OR = 5.333). Diabetic foot osteomyelitis is usually a chronic infection and requires surgical therapy. Amputation is the accepted form of treatment for osteomyelitis. Limited limb-saving surgery and prolonged antibiotic therapy directed toward the definitive causative bacteria are most appropriate. This may decrease limb loss through amputations. As a result the infections caused by resistant bacteria may lead to a high cost of antibiotherapy, prolonged hospitalization duration, and failure of the treatment

Do patients infected with human coronavirus before the COVID-19 pandemic have less risk of being infected with COVID-19?

Background/aim: Although seasonal human coronaviruses (HCoVs) have long been recognized as respiratory tract viruses, the newlyidentified SARS-CoV-2 caused a pandemic associated with severe respiratory failure. We aimed to evaluate the incidence of COVID-19infection in patients diagnosed in three tertiary teaching hospitals, both with and without prior confirmed HCoV infection, and tocompare these cohorts in terms of COVID-19 contraction.Materials and methods: In our study, we examined HCoV PCR-positive cases obtained retrospectively between January 2014 andMarch 2020 from three University Hospital Microbiology Laboratories (Cohort 1), as well as PCR-negative patients detected in the samePCR cycle as the positive cases (Cohort 2). We also evaluated subgroups of HCoV-positive cases.Results: There was no difference in COVID-19 contraction rates between Cohort 1 and Cohort 2 (p = 0.724). When previous HCoVsubgroups of COVID-19-positive patients were examined, no significant difference was found between the betacoronavirus andalphacoronavirus subgroups (p = 0.822), among the four groups (NL63, 229E, OC43, HKU-1) (p = 0.207), or between the OC43subgroup and the other groups (p = 0.295).Conclusion: Being previously infected with HCoV did not provide protection against COVID-19 in our study group. We suggestevaluating the possible effect of previous OC43 infection on COVID-19 contraction in larger cohorts.</p