Israel Medical Association Journal

Background: Antibiotic resistance is a worldwide problem associated with increased morbidity and mortality.

Objectives: To evaluate multidrug resistant (MDR) bacteria carriage in selected populations.

Methods: Data were collected from all patients under 18 years who met our internal guidelines from 2015–2016. They were screened for carbapenem-resistant Enterobacteriaceae (CRE), extended spectrum beta-actamase (ESBL), methicillin-resistant Staphylococcus aureus (MRSA), and vancomycin-resistant enterococci (VRE). Indications for screening were non-resident non-Israeli patients (from the Palestinian Authority, Syria, and foreign patients), internal transfers from intensive care units, admission to high-risk departments, recent carriage of MDR bacteria, transfer from other hospitals, and recent hospitalization. Data were analyzed for MDR bacteria from at least one screening site (rectal, nasal, axillary, groin, throat). All data were analyzed per patient and per sample.

Results: During the study period 185/2632 positive screening sets (7%) were obtained from 725 patients. Of these, 165 patients (22.7%) were positive for at least one pathogen. Significantly fewer Israeli residents (120/615, 19.5%) tested positive compared to non-Israeli residents (45/110, 40.9%; P < 0.001). Past MDR bacteria carriage was the only significant screening indication (25/61, 41%; P < 0.001). CRE, VRE, MRSA, and ESBL prevalence rates were 0.6% (5/771), 0.5% (3/560) 0.5%, 4.2% (37/888), and 33.7% (139/413), respectively. Among non-ESBL carriers, MRSA was predominant with 38 positive cultures (n=34).

Conclusions: Non-Israeli non-residents and patients with previous positive MDR screening are at higher risk for MDR bacteria. Indications used to identify high-risk patients for drug resistant pathogens were efficacious. More effort is needed to reduce excessive sampling.

The development of antibiotic agents has revolutionized the treatment of infectious diseases and clinical practice. However, antibiotic overuse, together with biologic evolution, has resulted in escalating antibiotic resistance of bacteria; with the One Health concept, it affects our planet including animals, aquatic wildlife, rivers, groundwater, lakes, sea water, aqua farming, and soil. This situation threatens our ability to treat infections effectively in the near future and raises the alarming question of whether we are getting close to the post-antibiotic era. Several measures are suggested to prevent the apocalyptic consequence of antibiotic overuse, few of which are novel with thinking outside the box.

Background: Carbapenem-resistant Acinetobacter baumannii (CRAB) is an important cause of nosocomial infections. Active surveillance for CRAB carriage to identify and isolate colonized patients is used to reduce transmission.

Objectives: To assess the rate and risks of clinical infection among CRAB-carrier and non-carrier patients.

Methods: Hospitalized patients from whom CRAB screening-cultures were obtained between January and June 2018 were identified retrospectively. All CRAB-carriers were compared to a convenient sample of non-carriers and were followed to detect development of CRAB clinical infection during admission.

Results: We compared 115 CRAB carriers to 166 non-carriers. The median age in the study group was 76 years (IQR 71–87) vs. 65 years (55–79) in the non-carriers group (P < 0.001). Residence in a nursing facility, debilitated state, and admission to medical wards vs. intensive care units were more frequent among CRAB-carriers (P < 0.001). Mechanically ventilated patients included 51 CRAB carriers (44%) and 102 non-carriers (61%). Clinical infection developed in 49 patients (17%), primarily CRAB pneumonia. Of the CRAB-carriers and non-carriers, 26/115 (23%) and 23/166 (14%), respectively, developed a clinical infection (P = 0.05). One-third of the ventilated patients were infected. Debilitated state and antibiotic treatment during hospitalization were linked to higher infection rates (P = 0.01). Adjusted analysis showed that mechanical ventilation and CRAB colonization were strongly associated with clinical infection (P < 0.05).

Conclusion: The rate of CRAB infection among carriers was high. Mechanical ventilation and CRAB colonization were associated with CRAB clinical infection, primarily pneumonia

Background: Urinary tract infection (UTI) is a common bacterial infection in children.

Early treatment may prevent renal damage in pyelonephritis. The choice of empiric antibiotic treatment is based on knowledge of the local susceptibility of urinary bacteria to antibiotics. In Israel the recommended empiric oral antibiotic treatment are First or second generation cephalosporin, trimethoprim-sulfamethoxazole or amoxicillin-clavulanic acid.

Objectives: To describe resistance rates of urine bacteria isolated from children with UTI in the community settings. Identify risk factors for resistance.

Methods: A retrospective cross-sectional study of UTI in children aged 3 months to 18 years diagnosed with UTI and treated as outpatients in a large community clinic between 7/2015 and 7/2017 with a diagnosis of UTI.

Results: A total of 989 urinary samples were isolated, 232 were included in the study. Resistance rates to cephalexin, cefuroxime, ampicillin/clavulanate and Trimethoprim-Sulfamethoxazole were 9.9%, 9.1%, 20.7%, and 16.5%, respectively. Urinary tract abnormalities and recurrent UTI were associated with an increase in antibiotic resistance rates. Other factors such as age, fever, and previous antibiotic treatment were not associated with resistance differences.

Conclusions: Resistance rates to common oral antibiotics were low compared to previous studies performed in Israel in hospital settings. First generation cephalosporins are the preferred empiric antibiotics for febrile UTI for outpatient children. Amoxicillin/clavulanate is not favorable due to resistance of over 20% and the broad spectrum of this antibiotic. Care should be taken in children with renal abnormalities as there is a worrying degree of resistance rates to the oral first line antibiotic therapy.

Background: Empiric treatment for Helicobacter pylori is influenced by antibiotic susceptibility of infecting strains. A rise in the resistance rate to clarithromycin and metronidazole has been reported in pediatric populations.

Objectives: To assess the primary and secondary antibiotic resistance of H. pylori isolates in Israeli children and adolescents.

Methods: A retrospective review of H. pylori isolates cultured from antral biopsies of consecutive children aged 1 to 18 years, who were referred to the Pediatric Gastroenterology Unit, Kaplan Medical Center, over a 2.8 year period, was performed. Antibiotic susceptibility to clarithromycin, metronidazole, amoxicillin, tetracycline, and levofloxacin was determined by E-test. Data on the age of the patient, indication for endoscopy, and antibiotic treatment for H. pylori in previously treated children was collected.

Results: Cultures for H. pylori yielded 123 isolates. In children not previously treated (n=95), the primary global resistance was 38% with resistance to clarithromycin 9.5%, metronidazole 32.6 %, and to both 4.2%. Respective rates of resistance in previously treated children (n=28) were 71% (P = 0.002), 29% (P = 0.02), and 61% (P = 0.007). Simultaneous resistance to both drugs was found in 18% (P = 0.02). All H. pylori strains were susceptible to amoxicillin, tetracycline, and levofloxacin. Past eradication treatment was the only independent risk factor for antibiotic resistance in multivariate analysis.

Conclusions: Significantly higher resistance rates were found in previously treated patients, stressing the need to refrain from empiric treatment using the "test and treat strategy." Culture-based treatment strategy should be considered in all previously treated children.

Background: Little is known about the incidence of urinary tract infections (UTI) in the dispersed Bedouin population. UTIs are routinely treated empirically according to local resistance patterns, which is important when evaluating the risk factors and antibiotic resistance patterns in the Bedouin population.

Objectives: To analyze risk factors, pathogens, and antibiotic resistance patterns of UTIs in the Bedouin population compared to the general population in southern Israel. To compare data from this study to that from a previous study conducted at our center.

Methods: We prospectively followed all patients hospitalized with community acquired UTIs during a 4 month period at Soroka Medical Center. We also compared results from this study to those from a study conducted in 2000.

Results: The study comprised 223 patients: 44 Bedouin (19.7%), 179 (80.3) non-Bedouin; 158 female (70.9%), 65 male (29.1). The Bedouin were younger (51.7 vs. 71.1 years of age, P < 0.001) and had a lower Charlson Comorbidity Index (2.25 vs. 4.87, P < 0.001). Enterobacteriaceae were the most common pathogens identified, and Escherichia coli (E. coli) was the most common with 156 (70%) strains identified, followed by Klebsiella spp. with 29 (13%), Proteus spp. with 18 (8%), pseudomonas with 9 (4%), and other bacteria including enterococci with 11 (5%). The prevalence of E. coli increased significantly from 56% in 2000 to 70% in this study. We also noted an increase in community acquired extended spectrum beta lactamase (ESBL) pathogens from 4.5% in 2000 to 25.5% in the present study. No statistically significant difference was observed between the Bedouin and general populations in the causal pathogens, resistance to antibiotics, length of therapy, and readmission rate within 60 days. 

Conclusions: The Bedouin population hospitalized for UTIs is younger and presents with fewer co-morbidities. Isolated pathogens were similar to those found in the general population as was the presence of drug resistant infections. Overall, a substantial percentage of pathogens were resistant to standard first-line antibiotics, driving the need to change from empiric therapy to aminoglycoside therapy. 

 

Background: The epidemiology of bacteremic febrile neutropenia differs between locations and constitutes the basis for selection of empiric antibiotic therapy for febrile neutropenia.

Objectives: To describe the epidemiology of bacteremia among patients with neutropenia in a single center in Israel.

Methods: We conducted a prospective data collection on all patients with neutropenia (< 500/mm³) and clinically significant bacteremia or fungemia during the period 1988–2004.

Results: Among adults (462 episodes) the most common bloodstream isolate was Esherichia coli. Gram-negative bacteria predominated throughout the study period and the ratio between Gram-negative and Gram-positive bacteremia increased from 1.7 to 2.3 throughout the study period. Among children (752 episodes), the ratio between Gram-negative and Gram-positive bacteremia reversed from 1.2 to 0.7, due to increasing prevalence of coagulase-negative staphylcoccal bacteremia. Both among adults and children, the length of hospital stay prior to bacteremia had a major impact on the pathogens causing bacteremia and their antibiotic susceptibilities. The prevalence of E. coli decreased with time in hospital, while the rates of Pseudomonas aeruginosa, Klebsiella pneumoniae, Enterobacter spp., Acinetobacter spp., Enterococcus spp. and Candida spp. increased. Resistance to broad-spectrum empiric monotherapy in our center was observed in > 40% of Gram-negative bacteria when bacteremia was acquired after 14 days in hospital.
Conclusions: Improved infection-control measures for neutropenic cancer patients in our center are needed. Empiric antibiotic treatment should be tailored to patients’ risk for multidrug-resistant organisms. Individual hospitals should monitor infection epidemiology among cancer patients to guide empiric antibiotic treatment

Objectives: To test the in vitro activity of linezolid (oxazolidinone) and other antimicrobial agents against MRSA[1] isolates recovered from hospitalized patients.

Methods: We tested 150 MRSA isolates recovered from hospitalized patients. The minimal inhibitory concentration of vancomycin, teicoplanin, pristinamycin (quinupristin-dalforistin), and linezolid was determined by the Etest method. Susceptibility to other antibiotics was tested by the disk diffusion method.

Results: All isolates were sensitive to vancomycin, teicoplanin, pristinamycin, and linezolid. The MIC₉₀ was 2.0 mg/ml for vancomycin and teicoplanin (range 0.5–2.0 mg/ml and 0.125–2.0 mg/ml, respectively), and 0.5 mg/ml for pristinamycin and linezolid (range 0.125–0.75 mg/ml and 0.125–0.5 mg/m, respectively). Of the other antibiotics, fusidic acid showed the best in vitro activity, with 96.7% susceptibility, associated with trimethoprim/sulfamethoxazole (85.8%) and minocycline (84%). Penicillin was associated with the lowest susceptibility (1.3%), associated with ofloxacin (3%) and erythromycin (14%). An increase in the minimal inhibitory concentration value of vancomycin was associated with a significant decrease in resistance to TMP-SMZ[2] (P < 0.01) and an apparent increase in resistance to other antibiotics.

Conclusion: The excellent in vitro activity of linezolid and its reported in vivo effectiveness renders it an important therapeutic alternative to vancomycin in the treatment of MRSA infection.

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[1] MRSA = methicillin-resistant Staphylococcus aureus

[2] TMP-SMX = trimethoprim/sulfamethoxazole