Clinical Management of a Pandrug-Resistant OXA-48 Klebsiella pneumoniae Infection in the Pediatric Intensive Care Unit

Background: Carbapenem-resistant Klebsiella pneumoniae (CRKP) is one of the serious forms of health care-associated infection. Pan-drug resistant (PDR) CRKP infections can cause severe infections. Mortality and treatment costs in the pediatric intensive care unit (PICU) are high. This study aims to share our experience regarding the treatment of oxacillinase (OXA)-48-positive PDR-CRKP infection in our 20-bed tertiary PICU with isolated rooms and 1 nurse for every 2-3 patients. Methods: Patient demographic characteristics, underlying diseases, previous infections, source of infection PDR-CRKP, treatment modalities, measures used, and outcomes were recorded. Findings: Eleven patients (eight men and three women) were found to have PDR OXA-48-positive CRKP. Because of the simultaneous detection of PDR-CRKP in three patients and the rapid spread of the disease, it was classified as a clinical outbreak, and strict infection control measures were taken. Combination therapy with double carbapenemase (meropenem and imipenem), amikacin, colistin, and tigecycline was used for treatment. The mean duration of treatment and isolation was 15.7 and 65.4 days, respectively. No treatment-related complication was observed, only one patient died, and the mortality rate was 9%. Conclusions: This severe clinical outbreak can be successfully treated with effective treatment with combined antibiotics and strict adherence to infection control measures. ClinicalTrial.gov ID: 28/01/2022 - 1/5.

PCR evaluation of false-positive signals from two automated blood-culture systems

Rapid detection of micro-organisms from blood is one of the most critical functions of a diagnostic microbiology laboratory. Automated blood-culture systems reduce the time needed to detect positive cultures, and reduce specimen handling. The false-positive rate of such systems is 1–10 %. In this study, the presence of pathogens in ‘false-positive’ bottles obtained from BACTEC 9050 (Becton Dickinson) and BacT/Alert (Biomérieux) systems was investigated by eubacterial and fungal PCR. A total of 169 subculture-negative aerobic blood-culture bottles (104 BacT/Alert and 65 BACTEC) were evaluated. Both fungal and eubacterial PCRs were negative for all BACTEC bottles. Fungal PCR was also negative for the BacT/Alert system, but 10 bottles (9·6 %) gave positive results by eubacterial PCR. Sequence analysis of the positive PCR amplicons indicated the presence of the following bacteria (number of isolates in parentheses): Pasteurella multocida (1), Staphylococcus epidermidis (2), Staphylococcus hominis (1), Micrococcus sp. (1), Streptococcus pneumoniae (1), Corynebacterium spp. (2), Brachibacterium sp. (1) and Arthrobacter/Rothia sp. (1). Antibiotic usage by the patients may be responsible for the inability of the laboratory to grow these bacteria on subcultures. For patients with more than one false-positive bottle, molecular methods can be used to evaluate the microbial DNA in these bottles. False positives from the BACTEC system may be due to elevated patient leukocyte counts or the high sensitivity of the system to background increases in CO2 concentration.

Mupirocin vs terbinafine in impetigo

OBJECTIVE

Terbinafine is an antifungal drug known to have also antibacterial activity against certain Gram-positive and Gram-negative bacteria. It seems that antibacterial and antifungal activity of terbinafine may have an advantage in the treatment of mixed fungal and bacterial superficial skin infections. Nevertheless, clinical relevance of the antibacterial part of its action has not been investigated efficiently. To compare the efficacy and safety of terbinafine with those of mupirocin, which has already proven antibacterial action, in the treatment of impetigo.

METHODS

Children clinically diagnosed as having impetigo were treated with topical mupirocin or topical terbinafine in a randomized fashion. Patients' lesions were examined clinically on days 0, 4, 7, 10 and bacteriologic cultures were obtained on days 0 and 10.

RESULTS

A total of 62 patients were included in the study. Forty-eight of these patients were eligible for the efficacy and safety analysis. Twenty-five and 23 patients were treated with mupirocin and terbinafine, respectively. The clinical cure rates were 100% for the mupirocin group and 70% for the terbinafine group (p < 0.05). The bacteriological eradication rate for mupirocin-treated children was 100% and that for terbinafine-treated children was 78% (p < 0.05). Presence of bullous lesions appeared to be a factor for poor clinical outcome in the terbinafine group. Mild local adverse effects were noted in a small percentage of patients in each group.

CONCLUSION

Antibacterial activity of terbinafine is not strong enough to be an alternative in the treatment of impertigo. It is advisable that terbinafine could be used in combination with an antibacterial drug for superficial skin infections caused by both fungi and bacteria.

Investigation of Candida dubliniensis in Candida spp.-positive hemocultures

Candida dubliniensis is one of the Candida species which was first recognized in 1995. The yeast was misidentified because of its phenotypic similarities with Candida albicans. In this study, blood samples of patients from various departments at Ankara University Medical Faculty between January 1996 and September 2000 were investigated for distribution of Candida spp. and presence of C. dubliniensis. Ninety-eight culture positive fungi were included in the study. Phenotypic tests for identification of C. dubliniensis and tests for differentiation of the yeast from C. albicans, such as colony morphology on Staib agar, growth at 42 degrees C and 45 degrees C, beta-glucosidase activity and carbohydrate assimilation, were carried out. Sixty-four of the isolates produced germ tubes and chlamydospores, and none of them had the phenotypic characteristics of C. dubliniensis. Further large-scale studies of specific patient groups are necessary to reveal the etiologic importance of this yeast.

Drug resistance of Salmonella strains isolated from community infections in Ankara, Turkey, 1993-99

160 Salmonella strains were isolated from children at the paediatrics department of Ankara University. 48.1% of the isolates were Salmonella enteritidis, 41.9% Salmonella typhimurium and 10% other serotypes. For the analysis of data, the study period was divided into 2 periods: 1993-95 and 1996-99. A decline in the isolation rate of S. typhimurium (from 63.1% to 30.1%) and rapid rise in S. enteritidis (from 31.6% to 57.3) was observed during the review period. However, for S. typhimurium isolates, the 5-drug (ampicillin, chloramphenicol, streptomycin, tetracycline and sulfonamides) pattern of resistance was increased from 13.5% to 38.7% in the second period. Since S. enteritidis and 5-drug-resistant S. typhimurium have also increased in other countries, their pandemic spread in humans indicates the continuing importation and exportation of these pathogens.

Drug resistance of Shigella strains isolated in Ankara, Turkey, 1993-1996

289 Shigella strains were isolated from children at the paediatrics department of Ankara University. 75% of the isolates were S. sonnei and 24.8% were S. flexneri. Each strain was tested for resistance to 9 antimicrobial agents. 79% of the isolates were resistant to streptomycin (S), 56% to tetracycline (T), 55.7% to trimethoprim-sulfamethoxazole (SXT), 27.7% to ampicillin (Am) and 19.7% to chloramphenicol (C). None of the isolates was resistant to ciprofloxacin, nalidixic acid, cephalothin, ampicillin-sulbactam and ceftriaxone. 56% of the isolates were resistant to 3 or more antimicrobial agents. The most frequent pattern of resistance of S. sonnei and S. flexneri strains was SXT, T, S (39.6%) and Am, SXT, T, S, C (48.6%), respectively (p < 0.0001). These results demonstrate that trimethoprim-sulfamethoxazole should not be used in the treatment of shigellosis.