In vivo susceptibility of ESBL producing Escherichia coli to ceftriaxone in children with acute pyelonephritis.

INTRODUCTION: The choice of empiric therapy of acute pyelonephritis (APN) in children should be based on the knowledge of Escherichia coli (E. coli) as the most common uropathogen and its antibiotic sensitivities considering that nowadays ESBL-producing [ESBL (+)] E. coli is on the rise worldwide. OBJECTIVE: To examine in vivo susceptibility of ESBL (+) E. coli to ceftriaxone (CTX), and to evaluate the options for empiric therapy for APN in children. METHODS: Retrospective study of CTX empiric therapy of APN in children treated at the University Children's Hospital in Belgrade from January 2005 to December 2009. ESBL phenotypic confirmatory test with ceftazidime, CTX and cefotaxime was performed for all urine isolates by disc diffusion method on Mueller-Hinton agar plates. In vivo sensitivity of CTX documented by clinical response to empiric CTX therapy was compared between two groups of children: group I with ESBL (+) E. coli and group II with ESBL (-) E. coli APN. RESULTS: Group I with ESBL (+) APN consisted of 94 patients and group II of 120 patients with ESBL (-) APN, respectively. All patients received CTX as empiric therapy at a mean dose of 66.9 mg during 7.2 +/- 2.6 days of therapy. Clinical effect of CTX was similar in patients with ESBL (+) compared to those with ESBL (-) APN. CONCLUSIONS: In vitro resistance of ESBL E. coli to CTX determined by standard methods is not sufficiently predictive for its in vivo sensitivity. Therefore CTX may be used as empiric therapy for acute pyelonephritis in children.

Antibiotic resistance of uropathogens in newborns and young children with acute pyelonephritis.

INTRODUCTION: Urinary tract infection is common in childhood. Depending on the localization of the infection, severity of its clinical presentation and possible acute and long-term complications, it may be described as either acute cystitis or acute pyelonephritis. OBJECTIVE: The aim of this study was to assess the resistance patterns of uropathogens during the last 5 years in newborns and young children with acute pyelonephritis. METHODS: Uropathogens resistance to commonly usable anti-microbial agents (ampicillin, a combination of sulphamethoxasole and trimethoprim, cephalexin, ceftriaxone, cefotaxime, ceftazidime, gentamycin, amikacin, ciprofloxacin, imipenem and nalidixic acid) was retrospectively studied in newborns and young children treated during early (2005-2007) and late (2008-2009) study periods. Anti-bacterial susceptibility testing of the urine isolates was performed by the standard disc diffusion method. RESULTS: 117 newborns and 294 children aged 9.3 +/- 0.7 months were treated during early (n=136) or late (n=275) study period due to the first episode of acute pyelonephritis. Escherichia coli was the most common bacterial pathogen (85.5%). Compared to children older than one month, newborns had higher degree of antibacterial resistance to 2nd and 3rd generation cephalosporins, aminoglycosides, and nalidixic acid during early, and to ceftazidime, aminoglycosides and nalidixic acid during late study period. Also, multidrug resistance was more common in newborns during the early study period. CONCLUSION: Newborns had higher rate of antibacterial resistance than young children.The progressive increase of anti-microbial resistance in children with acute pyelonephritis is of great concern.

[Value of a rapid test for identification of beta-hemolytic streptococcus antigens in children with streptococcal pharyngitis]. / Vrednost testova za brzu identifikaciju antigena beta-hemolitickog streptokoka kod dece sa streptokoknim faringitisom.

Beta-hemolytic group A streptococcus (Streptococcus pyogenes) is the most common bacterial agent associated with the upper respiratory tract infections in humans. The most frequently group A streptococcus-associated disease is pharyngitis. Males and females are equally affected by group A streptococcus. There is seasonal increase in the prevalence of group A streptococcus-associated pharyngitis. Streptococcal pharyngitis is most prevalent in winter and early spring with higher incidence of disease observed in crowded population such as school children. Early diagnosis and treatment of group A streptococcal pharyngitis has been shown to reduce the severity of symptoms and further complications such as rheumatic fever and glomerulonephritis. The conventional methods used for identification of group A streptococci depend on isolation and identification of the organism on blood agar plates. These methods usually require 18-24 hours of incubation at 37 degrees C. Such delay in identifying the group A streptococcus has often made physicians to administer therapy without first disclosing the etiological agent. Development of immunologic tests, capable of detecting the group A streptococcal antigen directly from the throat swabs, produced rapid test results employed for better treatment of patients. STREP A test is a rapid immunochromatographic test for the detection of group A streptococci from throat swabs or culture. The accuracy of the test does not depend on the organism viability. Instead, group A strep antigen is extracted directly from the swab and identified using antibodies specific for the group A carbohydrates. We compared rapid test with conventional throat swab in 40 children, who met Centor criteria for streptococcal pharyngitis (absence of cough, high fever, purulent pharyngitis, enlarged and painful cervica lymph nodes). Overall congruence of rapid test and culture was 94%. Test is easy to perform and it is recommended as the first diagnostic test for management of children with streptococcal pharyngitis. In children with negative test, but with characteristics highly suggestive of streptococcal infection, throat culture should be performed.

[Erythromycin-resistant Streptococcus pyogenes]. / Resistencija sojeva Streptococcus pyogenes na eritromicin.

Streptococcus pyogenes is the most prevalent cause of tonsillopharyngitis in children. The drug of choice for infections caused by this microorganism is penicillin. The problem of treating such infections arises when erythromycin-resistant strains occur. The aim of the study was to determine the prevalence of Streptococcus pyogenes resistant to erythromycin. The organism was recovered from the pharynx of children hospitalized or treated on outpatient basis at the University Children's Hospital in Belgrade. Streptococcus pyogenes was identified on blood agar, using bacitracin disc, and confirmed by latex agglutination test (Slidex bioMerieux). Disc diffusion test was carried out to estimate the penicillin resistance. Erythromycin disc was used as screening method to detect erythromycin-resistant Streptococcus pyogenes. MIC for erythromycin was performed by broth dilution method. In the study period from January 2001 to December 2003, all 1100 isolates of Streptococcus pyogenes had usual level of penicillin sensitivity. In 2001, only 0.45% of isolates were erythromycin-resistant. In 2002, erythromycin resistance was 0.63%, while in 2003, it was 1.09%. MIC for erythromycin was from 1 to 128 mg/l. Three strains had constitutive and one strain had inducible resistance to clindamycin. According to the results, our conclusion is that, despite sensitivity to penicillin, resistance to macrolides is the emerging phenomenon. Reasonable use of macrolide antibiotics is necessary to maintain the resistance at the lowest level.