Antibiotic-resistant invasive pediatric Streptococcus pneumoniae clones in Israel

Antibiotic-resistant international clones of Streptococcus pneumoniae are increasingly reported in different parts of the world. We investigated the spread of these clones through an active surveillance performed at the Israeli Streptococcal National Center during 1998 and 1999. Isolates were tested for antibiotic susceptibility, serotyped, and genotyped by random amplified polymorphic DNA analysis and pulsed-field gel electrophoresis. Of 437 isolates, 276 (63.4%) were antibiotic resistant and 156 (35%) were penicillin nonsusceptible (PNS). The PNS isolates were less frequently encountered in southern Israel (27 of 136 [20%]) than in other regions (127 of 301 [42%]). Among 276 antibiotic-resistant isolates, 43 fingerprint patterns were observed. The most common clones were 9V/14-a (19.2%), 5-a (17.8%), and 1-a (10%). The 9V/14-a clone was less common, while the 1-a clone was more frequent in the south than in other regions. The 5-a clone was more common in Jerusalem than in other regions. Among the Jewish and Arab populations the most frequent clones were 9V/14-a (20%) and 1-a (25%), respectively. Three international clones, 9V/14-a-Spain(9V)-3, 6B-a-Spain(6B)-2, and 5-a-Colombia(5)-19, comprised 40% of all antibiotic-resistant isolates and 56% of all PNS isolates. The seven-valent conjugate vaccine covers 58% of the most common clones, all highly PNS clones, and 94% of the multidrug-resistant clones in Israel, while the nine-valent vaccine covers all of them. The most common antibiotic-resistant invasive pediatric S. pneumoniae clones-mainly the three international ones-contribute significantly to increases in antibiotic resistance. Their geographic distribution varies within the country and between the different populations.     

Acute otitis media in infants younger than two months of age: microbiology,clinical presentation and therapeutic approach

BACKGROUND: Information on the causative agents of acute otitis media (AOM) in infants <2 months of age is limited. OBJECTIVES OF THE STUDY: To analyze the etiology, pathogen susceptibility patterns, clinical presentation and frequency of serious bacterial infections in infants <2 months of age with AOM and to determine the relationship between the organisms isolated systemically and those isolated from the middle ear fluid in the patients with serious bacterial infections in the presence of AOM. METHODS: The medical records of 137 infants <2 months of age with AOM who underwent tympanocentesis in the emergency room of Soroka University Medical Center between January 1, 1995, and May 30, 1999, were reviewed. The main variables analyzed included demography, frequency of serious bacterial infections, bacteriologic results, susceptibility patterns of the pathogens and clinical presentation. RESULTS: Median age was 38.7 +/- 13 days; 112 of 137 (82%) infants were hospitalized. Six (4%), 27 (20%), 46 (34%) and 58 (42%) episodes were recorded at age 0 to 2, 3 to 4, 5 to 6 and 7 to 8 weeks, respectively. Fever (temperature >38 degrees C) was present in 96 (70%) of the cases. Culture-negative (bacterial) meningitis was diagnosed in 3 cases. Blood and urine cultures were positive in 1 and 6 infants, respectively. None of the afebrile infants developed serious bacterial infection. One hundred twenty-two bacterial pathogens were isolated from the middle ear fluid of 109 of 137 (80%) patients: Streptococcus pneumoniae in 56 (46%), Haemophilus influenzae in 41 (34%), group A Streptococcus in 12 (10%), enteric gram-negative bacilli in 9 (7%), Moraxella catarrhalis in 3 (2%) and Streptococcus faecalis in 1 (1%). Eleven (20%) of the 56 S. pneumoniae isolates were nonsusceptible to penicillin. Serious bacterial infections were diagnosed in 6 of 137 (4%) patients. Whereas blood and urine grew pathogens typical for blood and urinary tract infections, the middle ear fluid isolates represented different pathogens usually isolated in AOM without any correlation between these 2 groups of pathogens. CONCLUSIONS: (1) Most cases of AOM in infants <2 months of age are caused by pathogens similar to those causing AOM in older children; (2) antibiotic resistance may already be present at early age and should be considered in the empiric treatment of AOM in infants <2 months of age; (3) the presence of AOM does not predict a higher risk for serious bacterial infections in afebrile and febrile infants <2 months of age.     

From caring to managing and beyond: an examination of the head nurse's role

AIM: The aim of this study was to depict the essence of what head nurses do, and how they perform their managerial role. METHODS: To achieve this, the work behaviour of 48 head nurses was examined by a semi-structured observation technique for 6 hours each. RESULTS: Results demonstrated that head nurses spent a large proportion of their time in clinical practice, followed by co-ordinating care, operating the unit's functions, and leading staff. Personnel management and quality improvement occupied only a marginal share of head nurses' time. CONCLUSIONS: These results implied that head nurses exhibited a management style orientated to maintenance rather than to re-creation, focusing more on the 'doing' and the 'here and now' aspects of the job than on leading, planning, and proactive problem solving.     

Spread of Streptococcus pneumoniae and antibiotic-resistant S. pneumoniae from day-care center attendees to their younger siblings

A prospective study was conducted to determine the association between pneumococcal carriage among 36 infants and young toddlers cared for at home and carriage among their older siblings who attended 8 day-care centers (DCCs); 71 pneumococcal strains acquired by the younger siblings were compared with those present in the DCCs for 6 months. In 76% of cases, > or =1 strain identical by serotype and antibiogram was isolated in the older siblings' DCC versus 32%-63% in all other DCCs (P<.001). When phenotypically identical strains were compared by pulsed-field gel electrophoresis, the similarity between strains from older siblings' DCCs and the younger siblings' isolates was striking. This was not found when isolates from other DCCs were compared. Vaccinating DCC attendees with a 7-valent pneumococcal conjugate vaccine may play a key role in controlling the spread of antibiotic-resistant pneumococci, because the most resistant serotypes are included in the vaccine.     

Serological criteria for evaluation and licensure of new pneumococcal conjugate vaccine formulations for use in infants

The World Health Organization (WHO) is undertaking a series of consultations on serological criteria for the evaluation and licensure of new formulations/combinations or different vaccination schedules of pneumococcal conjugate vaccines. The lack of a definitive serological correlate of protection and the multiplicity of antigens involved, especially since the clinical efficacy of most of the individual serotypes represented in the only licensed vaccine has not been established, are hindering the formulation of criteria for licensure of new formulations or combinations of the vaccine. This report analyses the various options with their relative merits and drawbacks and provides preliminary recommendations as guidance to regulatory agencies in evaluating these vaccines for the purposes of licensure. More detailed recommendations for production and control of pneumococcal conjugate vaccines, including criteria for evaluation for licensure, are currently being drafted.     

Augmentation of low-frequency ultrasound-induced clot disruption by hydroxyethyl starch is dependent on the duration and intensity of ultrasound exposure; an in vitro study

We investigated the synergistic effect between low-frequency ultrasound (US) and hydroxyethyl starch (HAES) on blood clot disruption, using different HAES concentrations, US duration and intensity. Human blood clots, 200 to 400 mg in weight, were placed in tubes containing 10 mL of normal saline alone or with HAES 0.1%, 1% or 2%. Clots were randomized to four intensities of US exposure: none, low, medium and high (maximal amplitude of motion at the tip of the horn: 0, 96, 144 and 192 micro m, respectively), and for three durations of US exposure (10, 20 and 40 s). After treatment, the clots were reweighed, and the percent differences in weights were calculated. US intensity, US duration and HAES concentration had a significant effect on the blood clot dissolution (p < 0.001 for all three variables). HAES augmented clot dissolution only when US intensity was medium or high. With low intensity, HAES did not augment clot lysis. CONCLUSIONS: microparticle-containing solutions, such as HAES, have a potential for augmenting clot disruption by US. This effect is highly dependent on US intensity.     

Bacteriologic and clinical efficacy of high dose amoxicillin/clavulanate in children with acute otitis media.

OBJECTIVES: To determine the bacteriologic and clinical efficacy of high dose amoxicillin/clavulanate (90/6.4 mg/kg/day) against common bacterial pathogens causing acute otitis media (AOM), including penicillin-resistant Streptococcus pneumoniae (PRSP). METHODS: In this open label multicenter study, 521 infants and children with AOM [mean age, 18.6 months; age < 24 months, n = 375 (72%)] were treated with amoxicillin/clavulanate 90/6.4 mg/kg/day in two divided doses for 10 days. Bilateral otitis media, previous episodes of AOM, antibiotic treatment within 3 months and day-care attendance were recorded in 60.1, 35.7, 50.2 and 38.2% of the children, respectively. Tympanocentesis was performed before the first dose and repeated on Days 4 to 6 for all children with S. pneumoniae at 22 centers and for all children with any pathogen at 3 centers. Clinical response was assessed at end of therapy. RESULTS: Pathogens were isolated from 355 (68%) of 521 enrolled children; 180 children underwent repeat tympanocentesis and were bacteriologically evaluable. Baseline pathogens were S. pneumoniae (n = 122 enrolled/93 bacteriologically evaluable), Haemophilus influenzae (n = 160/51), both (n = 37/32) and others (n = 36/4). Pathogens were eradicated from 172 (96%) of 180 bacteriologically evaluable children. Overall 122 (98%) of 125 isolates of S. pneumoniae were eradicated, including 31 (91%) of 34 PRSP isolates (penicillin MICs 2 to 4 micrograms/ml). Seventy-eight (94%) of 83 isolates of H. influenzae were eradicated. Symptoms and otoscopic signs of acute inflammation were completely resolved or improved on Days 12 to 15 in 263 (89%) of 295 clinically evaluable children with bacteriologically documented AOM. CONCLUSIONS: On the basis of bacteriologic outcome on Days 4 to 6 and clinical outcome on Days 12 to 15, we found that high dose amoxicillin/clavulanate (90/6.4 mg/kg/day) was highly efficacious in children with AOM, including those most likely to fail treatment, namely children < 24 months of age and those with infectious caused by PRSP.