Israel Medical Association Journal

Background: Pseudomonas aeruginosa (PSA) is an infectious pathogen associated with acute appendicitis; however, it is not consistently addressed by empirical antibiotic therapy, despite potential complications.

Objectives: To investigate the incidence, predictors, and outcomes of PSA-associated acute appendicitis in children.

Methods: We conducted a retrospective analysis involving pediatric patients who underwent acute appendicitis surgery and had positive peritoneal cultures. Clinical, microbiological, and intraoperative data were extracted from medical records.

Results: Among 2523 children with acute appendicitis, 798 (31.6%) underwent peritoneal cultures, revealing 338 positive cases (42.3%), with PSA detected in 77 cases (22.8%). Children with PSA were three times more likely to exhibit high intraoperative grading ≥ 3 (93.4% vs. 76.8%, 95% confidence interval [95%CI] 1.2–8.3, P = 0.023) and nearly four times more likely to have polymicrobial cultures (88.3% vs. 62.1%, 95%CI 1.8–8.0, P < 0.001) than those without PSA in peritoneal cultures. Duration of symptoms did not predict PSA isolation (P = 0.827). Patients with PSA had longer median hospital stays (8 days, interquartile range [IQR] 7–10) than those with other pathogens (7 days, IQR 5–9) (P = 0.004). Antibiotic treatment duration, intensive care unit admission rates, readmission, and mortality were similar between the two groups (P = 0.893, 0.197, 0.760, and 0.761, respectively).

Conclusions: PSA is a common pathogen in children diagnosed with acute appendicitis and positive peritoneal cultures. The likelihood of isolating PSA increases with high-grade intraoperative assessment and in the presence of multiple pathogens in peritoneal cultures, suggests antipseudomonal treatment.

Background: Bronchiectasis is an obstructive chronic lung disease characterized by structural changes in large and small airways, namely permanent widening of bronchial lumen resulting in chronic inflammation and infection. Nontuberculous mycobacteria (NTM) are environmental mycobacteria that may cause human infection or colonization with over 150 species identified to date. Bronchiectasis with NTM colonization or infection is often encountered but with varying prevalence and unknown clinical or prognostic significance.

Objectives: To find the prevalence of NTM among patients with bronchiectasis in the Jerusalem district. To assess whether there were clinical differences between patients with bronchiectasis who were isolated with NTM and those without.

Methods: In this retrospective observational research study, we reviewed all computerized medical charts of patients over 18 years of age, who were diagnosed with bronchiectasis at Hadassah Medical Centers in Jerusalem between 2012 and 2017. We assessed the prevalence of NTM pulmonary disease. To compare patients with and without NTM, we reviewed and analyzed clinical, radiological, and microbiological data of all NTM patients and a group of controls in a 4:1 ratio.

Results: Prevalence of NTM among bronchiectasis patients was 5.1%, slightly lower than previously reported in Israel. We did not find clinically or radiological significant differences in patients with NTM disease compared to controls. This result included a similar number of exacerbations, hospitalization rates, number of lobes involved, and pulmonary function tests.

Conclusions: Bronchiectasis patients with isolation of Pseudomonas aeruginosa experienced more exacerbations than patients with other isolates, consistent with previous studies.

Background: Chronic suppurative otitis media is a long-standing middle ear infection with a perforated tympanic membrane. Tympanoplasty is the mainstay of treatment. Most surgeons prefer to operate on dry ears; however, this may be difficult to achieve.

Objectives: To investigate the effect of otorrhea and positive cultures on the outcome of tympanoplasty.

Methods: This retrospective analysis reviewed patients with chronic suppurative otitis media who underwent tympanoplasty 2008–2015. Patients were divided into three groups: active discharge and bacterial growth, active discharge without bacterial growth, and no ear discharge. Surgical outcomes were compared among the groups.

Results: Among 101 patients included, 43 ears (42.6%) had discharge preoperatively, 58 (57.4%) were dry. Overall closure rate was 81.2% (82/101). Preoperative active discharge closure rate was 88.3% (38/43) and without discharge 75.9% (44/58). There were 38 positive cultures preoperatively and five negative cultures. Cultures were not obtained in 58 cases. Success rates were 89.5%, 80%, and 75.9%, respectively. No significant difference was found between patients who had positive or negative cultures before the procedure (P > 0.48) or among the three groups (P = 0.25). The most common bacteria were Pseudomonas aeruginosa (n=17), followed by Staphylococcus species (n=10). None was significantly associated with operative failure (P = 0.557). The postoperative air threshold difference was not affected by culture results (P = 0.3).

Conclusions: Tympanoplasty success rates and postoperative air threshold differences were not affected by the presence of preoperative otorrhea or positive ear cultures. Surgery can be performed even when the ear is not dry.

Background: Although indwelling catheters are increasingly used in modern medicine, they can be a source of microbial contamination and hard-to-treat biofilms, which jeopardize patient lives. At times 70% ethanol is used as a catheter-lock solution due to its bactericidal properties. However, high concentrations of ethanol can result in adverse effects and in malfunction of the catheters.

Objective: To determine whether low concentrations of ethanol can prevent and treat biofilms of Pseudomonas aeruginosa.

Methods: Ethanol was tested at a concentration range of 0.625–80% against laboratory and clinical isolates of P. aeruginosa for various time periods (2–48 hours). The following parameters were evaluated following ethanol exposure: prevention of biofilm formation, reduction of biofilm metabolic activity, and inhibition of biofilm regrowth.

Results: Exposing P. aeruginosa to twofold ethanol gradients demonstrated a significant biofilm inhibition at concentrations as low as 2.5%. Treating pre-formed biofilms of P. aeruginosa with 20% ethanol for 4 hours caused a sharp decay in the metabolic activity of both the laboratory and clinical P. aeruginosa isolates. In addition, treating mature biofilms with 20% ethanol prevented the regrowth of bacteria encased within it.

Conclusions: Low ethanol concentrations (2.5%) can prevent in vitro biofilm formation of P. aeruginosa. Treatment of previously formed biofilms can be achieved using 20% ethanol, thereby keeping the catheters intact and avoiding complications that can result from high ethanol concentrations.

Objectives: To assess our experience with perichondritis in a large group of patients hospitalized with this entity.

Methods: We retrospectively studied 114 patients who were admitted with perichondritis during 1987–2004, including their demographic details, medical history, current illness, etiology, pathogens and treatments. 

Results: The patients’ mean age was 41.8 ± 20.7 years. In more than half of the patients the etiology could not be determined. Forty-seven patients (41%) were treated prior to hospitalization for an average of 2.5 ± 1.9 days. Eight patients (7%) required surgical intervention. Pseudomonas aeruginosa was found to be the predominant organism (69% of available isolates) and was associated with a more advanced clinical presentation and longer hospitalization (P = 0.008). 

Conclusions:  Perichondritis develops in many cases after apparent minor trauma. Since P. aeruginosa is probably the predominant pathogen, initial treatment should include anti-pseudomonal antibiotics.

Background: Peritonitis is a major complication of chronic peritoneal dialysis therapy. It is recommended that each center monitor infection rates in order to define the local microbiological profile and implement an appropriate empiric antibiotic regimen.

Objectives: To analyze the microbiological profile of peritonitis in our pediatric dialysis unit and identify local predisposing factors.

Methods: In this retrospective study we reviewed the files of children treated with chronic PD[1] during the 10 year period 1997–2007.

Results: Eighty peritonitis episodes were recorded in 29 children (20 male, 9 female) aged 0.1–18.5 years (median 11.75) treated with peritoneal dialysis for 6–69 months (median 19) for a total of 578 patient-months. The annual peritonitis rate was 1.66/patient. The main pathogens were coagulase-negative Staphyloccocus (32.5%) and Pseudomonas spp. (16%), which were also cultured in most cases (64–69%) from the exit site during the 3 months preceding peritonitis. No peritonitis occurred in 31% of the patients (median age 12.5 years). All patients less than 5 years old had at least one peritonitis episode. Contaminating conditions (gastrostomy, enuresis, diaper use), found in 44% of the study group, and first infection within 6 months from starting PD were significantly associated with an increased peritonitis rate (P = 0.01, P = 0.009, respectively). Recurrent peritonitis led to a switch to hemodialysis in 18% of patients. There were no deaths.

Conclusions: The risk factors for peritonitis in our study were: first infection within less than 6 months from starting treatment, Pseudomonas exit-site colonization, and contaminating conditions (gastrostomies, diaper use, enuresis). These susceptible subgroups as well as very young age (< 5 years) at starting PD should be especially targeted during training of caregivers and follow-up to prevent later complications.  

[1] PD = peritoneal dialysis

Background: Transmission of Pseudomonas aeruginosa among cystic fibrosis patients attending health camps has been reported previously.

Objectives: To determine the transmission of P. aeruginosa among CF[1] patients during three winter camps in the Dead Sea region in southern Israel.

Methods: Three consecutive CF patient groups were studied, each of which spent 3 weeks at the camp. The patients were segragated prior to camp attendance: patients who were not colonized with P. aeruginosa constituted the first group and colonized patients made up the two additional groups. Sputum cultures were obtained upon arrival, at mid-camp and on the last day. Environmental cultures were also obtained. Patients were separated during social activities and were requested to avoid social mingling. Isolates were analyzed by antibiotics susceptibility profile and by pulsed field gel electrophoresis.

Results: Ninety isolates from 19 patients produced 28 different fingerprint patterns by PFGE[2]. Isolates from two siblings and two patients from the same clinic displayed the same fingerprint pattern. These patients were already colonized with these organisms upon arrival. Two couples were formed during the camp, but PFGE showed no transmission of organisms. All other patients' isolates displayed unique fingerprint patterns and were distinguishable from those of other attendees, and none of the P. aeruginosa-negative patients acquired P. aeruginosa during camp attendance. Environmental cultures were negative for P. aeruginosa.

Conclusions: We were unable to demonstrate cross-infection of P. aeruginosa among CF patients participating in health camps at the Dead Sea who were meticulously segregated.