Community-acquired Pseudomonas aeruginosa urinary tract infections in children hospitalized in a tertiary center: relative frequency, risk factors, antimicrobial resistance and treatment

Dual transcriptional analysis reveals adaptation of host and pathogen to intracellular survival of Pseudomonas aeruginosa associated with urinary tract infection

Long-term survival of bacterial pathogens during persistent bacterial infections can be associated with antibiotic treatment failure and poses a serious public health problem. Infections caused by the Gram-negative pathogen Pseudomonas aeruginosa, which can cause both acute and chronic infections, are particularly challenging due to its high intrinsic resistance to antibiotics. The ineffectiveness of antibiotics is exacerbated when bacteria reside intracellularly within host cells where they can adopt a drug tolerant state. While the early steps of adherence and entry of P. aeruginosa into mammalian cells have been described, the subsequent fate of internalized bacteria, as well as host and bacterial molecular pathways facilitating bacterial long-term survival, are not well defined. In particular, long-term survival within bladder epithelial cells has not been demonstrated and this may have important implications for the understanding and treatment of UTIs caused by P. aeruginosa. Here, we demonstrate and characterize the intracellular survival of wild type (WT) P. aeruginosa inside bladder epithelial cells and a mutant with a disruption in the bacterial two-component regulator AlgR that is unable to survive intracellularly. Using simultaneous dual RNA-seq transcriptional profiling, we define the transcriptional response of intracellular bacteria and their corresponding invaded host cells. The bacterial transcriptional response demonstrates that WT bacteria rapidly adapt to the stress encountered in the intracellular environment in contrast to ΔalgR bacteria. Analysis of the host transcriptional response to invasion suggests that the NF-κB signaling pathway, previously shown to be required for extracellular bacterial clearance, is paradoxically also required for intracellular bacterial survival. Lastly, we demonstrate that intracellular survival is important for pathogenesis of P. aeruginosa in vivo using a model of murine urinary tract infection. We propose that the unappreciated ability of P. aeruginosa to survive intracellularly may play an important role in contributing to the chronicity and recurrence of P. aeruginosa in urinary tract infections.

Chronic persistent bacterial infections are a serious and growing public health problem worsened by the rise in antibiotic resistance, yet new approaches for treating these infections are lacking. These long-term infections can occur when bacteria invade and survive inside host cells where they can hide from the immune system and become less susceptible to killing by antibiotics. Pseudomonas aeruginosa, a bacterium conventionally considered an extracellular pathogen, can cause chronic infections of many organ systems, including the urinary tract. Here, we show that P. aeruginosa can in fact survive inside bladder epithelial cells and becomes tolerant to antibiotic treatment. Using gene expression analysis, we show that bacteria quickly adapt to the intracellular environment while the corresponding host cells upregulate the NF-κB signaling pathway. We demonstrate that this response, which had previously been shown to be required for clearance of extracellular bacteria, is paradoxically also required for survival of intracellular bacteria. We propose that the ability of P. aeruginosa to survive intracellularly plays an important role in contributing to the chronicity and recurrence of P. aeruginosa infections and that targeting host pathways, such as NF-κB signaling, could transform our ability to manage chronic and/or recurrent infections.

Elucidating the Structural Requirement of Uridylpeptide Antibiotics for Antibacterial Activity

The synthesis and biological evaluation of analogues of uridylpeptide antibiotics were described, and the molecular interaction between the 3'-hydroxy analogue of mureidomycin A (3'-hydroxymureidomycin A) and its target enzyme, phospho-MurNAc-pentapeptide transferase (MraY), was analyzed in detail. The structure-activity relationship (SAR) involving MraY inhibition suggests that the side chain at the urea-dipeptide moiety does not affect the MraY inhibition. However, the anti-Pseudomonas aeruginosa activity is in great contrast and the urea-dipeptide motif is a key contributor. It is also suggested that the nucleoside peptide permease NppA1A2BCD is responsible for the transport of 3'-hydroxymureidomycin A into the cytoplasm. A systematic SAR analysis of the urea-dipeptide moiety of 3'-hydroxymureidomycin A was further conducted and the antibacterial activity was determined. This study provides a guide for the rational design of analogues based on uridylpeptide antibiotics.

Treatment outcome and predictors of poor clinical response in extensively drug-resistant gram-negative urinary tract infection among children: A single-institution experience

INTRODUCTION

Extensively drug-resistant (XDR) is defined as isolates sensitive only to two or fewer antimicrobial categories. This paper aims to present the treatment outcome and identify factors associated with poor clinical response among children with XDR gram-negative urinary tract infection (UTI).

METHODS

This is a retrospective cohort conducted at a tertiary pediatric hospital from January 2014 to June 2017. All patients diagnosed with culture-proven XDR gram-negative UTI were identified and analyzed. Descriptive statistics were used to summarize demographic and clinical characteristics. Patients were categorized according to treatment outcomes: success vs. failure. Univariate analysis and multivariate logistic regression were used to assess statistical differences between the groups and determined patient variables that are predictive of poor response. Odds ratio (OR) and corresponding 95% confidence interval (CI) were generated.

RESULTS

A total of 29 (19.2%) XDR gram-negative pediatric UTIs were identified within the 42-month study period. No significant differences were noted in demographic characteristics between the groups. Treatment outcome of XDR gram-negative UTI patients showed that combination therapy with colistin had the highest success rate (40.9%), followed by non-colistin (36.4%) and combination therapy without colistin (22.7%). However, univariate analysis showed no significant difference among the different treatment groups (p=0.65). On multivariate logistic regression, receiving immunosuppressant and the presence of indwelling urinary catheters were independent predictors of poor clinical response among pediatric patients with XDR gram-negative UTI (OR 19.44, 95% CI 1.50-251.4, p=0.023 and OR 20.78, 95% CI 1.16-371.28, p=0.039; respectively).

CONCLUSIONS

The treatment success rate of XDR gram-negative pediatric UTI ranged from 22.7-36.4%. This finding emphasizes the need to advocate antibiotic stewardship to prevent further increase in XDR UTIs. Indwelling urinary catheters and receipt of immunosuppressants are associated with poor clinical outcome.

Carbapenem-Resistant but Cephalosporin-Susceptible Pseudomonas aeruginosa in Urinary Tract Infections: Opportunity for Colistin Sparing

This paper briefly reports the occurrence and epidemiology of carbapenem-resistant but cephalosporin-susceptible (Car-R/Ceph-S) Pseudomonas aeruginosa isolates from urinary tract infections (UTIs) in a tertiary-care hospital in the Southern Region of Hungary, and the phenotypic characterization of the possible resistance mechanisms in these isolates. Isolates and data were collected regarding P. aeruginosa UTIs corresponding to the period between 2008 and 2017. Susceptibility testing was performed using the Kirby-Bauer disk diffusion method; minimum inhibitory concentrations (MICs) of the isolates were determined using E-tests. The phenotypic detection of ampicillin C-type (AmpC) β-lactamases, efflux pump overexpression and carbapenemase production was also performed. P. aeruginosa represented n = 575 (2.72% ± 0.64%) from outpatient, and n = 1045 (5.43% ± 0.81%) from inpatient urinary samples, respectively. Based on the disk diffusion test, n = 359 (22.16%) were carbapenem-resistant; in addition to carbapenems, n = (64.34%) were also resistant to ciprofloxacin; n = (60.17%) to gentamicin/tobramycin; n = (58.51%) to levofloxacin; and n = (27.57%) to amikacin. From among the carbapenem-resistant isolates, n = 56 (15.59%) isolates were multidrug-resistant, while n = 16 (4.46%) were extensively drug-resistant. From among the Car-R/Ceph-S isolates (n = 57), overexpression of AmpC was observed in n = 7 cases (12.28%); carbapenemase production in n = 4 (7.02%); while overexpression of efflux pumps was present in n = 31 (54.39%) isolates. To spare last-resort agents, e.g., colistin, the use of broad-spectrum cephalosporins or safe, alternative agents should be considered in these infections.

The functional biology of peanut allergens and possible links to their allergenicity

Peanut is one of the most common food triggers of fatal anaphylaxis worldwide although peanut allergy affects only 1%-2% of the general population. Peanuts are the source of highly potent allergenic proteins. It is emerging that the allergenicity of certain proteins is linked to their biological function. Peanut is an unusual crop in that it flowers aboveground but produces its seed-containing pods underground. This so-called geocarpic fruiting habit exposes pods and seeds during their development to soilborne pathogens and pests. Pest damage can also open routes of entry for opportunistic fungi such as Aspergillus. Although seed proteins have primary functions in nutrient reservoirs, lipid storage bodies, or the cytoskeleton, they have also evolved to act as part of the plant's defense system to enhance fitness and survival of the species. When interacting with pathogens or pests, these proteins modify and damage cells' membranes, interact with immune receptors, and modulate signaling pathways. Moreover, following exposure, the immune system of predisposed individuals reacts to these proteins with the production of specific IgE. This review explores the evolutionary biology of peanut and its seed proteins and highlights possible links between the proteins' biological function and their allergenicity.

Pseudomonas aeruginosa Quorum Sensing Systems as Drug Discovery Targets: Current Position and Future Perspectives

Antimicrobial resistance (AMR) is a serious threat to public health globally, manifested by the frequent emergence of multidrug resistant pathogens that render current chemotherapy inadequate. Health organizations worldwide have recognized the severity of this crisis and implemented action plans to contain its adverse consequences and prolong the utility of conventional antibiotics. Hence, there is a pressing need for new classes of antibacterial agents with novel modes of action. Quorum sensing (QS), a communication system employed by bacterial populations to coordinate virulence gene expression, is a potential target that has been intensively investigated over the past decade. This Perspective will focus on recent advances in targeting the three main quorum sensing systems ( las, rhl, and pqs) of a major opportunistic human pathogen, Pseudomonas aeruginosa, and will specifically evaluate the medicinal chemistry strategies devised to develop QS inhibitors from a drug discovery perspective.

Multiresistant E. coli urine infections in children: a case-control study

OBJECTIVE

Urinary tract infections (UTIs) caused by resistant organisms are increasing which poses challenges when selecting empirical antimicrobial therapy. The aim of this study is to determine risk factors for multiresistant Escherichia coli UTIs in children.

DESIGN

We included all reported urinary isolates from a children's hospital collected between January 2010 and June 2013. Patients who had multiresistant E. coli UTIs were identified and a retrospective review of medical records performed. Patient-specific clinical and demographic factors were compared with age-matched and gender-matched controls with non-multiresistant E. coli UTIs. Univariable and multivariable statistical analysis were performed to determine significant risk factors for multiresistant organism E.coli UTIs.

RESULTS

In total, there were 2692 positive urine cultures, 1676 (62.3%) from 1169 patients were E. coli. Multiresistant E. coli was isolated from 139 (8.3% of all E. coli) cultures in 99 patients. Thirteen incomplete medical records were excluded, leaving 86 patients, matched with 86 controls. In multivariable regression, the only significant risk factor was antibiotic use in the previous month (adjusted OR 3.0, 95% CI 1.4 to 6.2), but not previous hospital admission (adjusted OR 1.4, 95% CI 0.6 to 2.9), being an inpatient at the time of diagnosis (adjusted OR 2.4, 95% CI 0.8 to 7.4) and previous instrumentation (adjusted OR 1.0, 95% CI 0.4 to 2.4).

CONCLUSIONS

This is the first case-control study to examine multiresistant UTI in Australian children. Clinicians should be judicious in the use of antibiotics in treatment and prophylaxis of UTIs. In children presenting with UTI and recent antibiotic exposure, amoxicillin-clavulanic acid appears to be an appropriate empiric antibiotic choice in our population.

Antimicrobial Pharmacotherapy Management of Urinary Tract Infections in Pediatric Patients

Objective: To discuss the risk factors, microbial resistance rates, and pharmacotherapy, including antimicrobial choices and medication dosage regimens, for urinary tract infections (UTIs) in pediatric patients. Data Sources: A MEDLINE literature search (1985 to December 2017) was performed using the following keywords and associated medical subject headings: urinary tract infection, antimicrobial, treatment, and children. Study Selection and Data Extraction: Search was conducted to identify clinical trials, systematic reviews, and guidelines. Search was filtered to include studies with age range between birth and 18 years and published in English. Additional references were identified from selected review articles. Data Synthesis: In total, 27 studies investigating microbial resistance, 31 studies assessing antimicrobial efficacy, 34 studies describing prophylaxis, and 6 systematic reviews were included. The resistance patterns differed across age groups and affected the choice of empirical therapy. If pyelonephritis is suspected, empiric antimicrobials should have high urinary and sufficient parenchymal concentrations. Nitrofurantoin has low microbial resistance rates and can generally be used empirically for treating uncomplicated cystitis in children >1 month of age. Trimethoprim-sulfamethoxazole resistance has increased and should be avoided unless local susceptibility data are available. Certain patients with recurrent UTIs or renal abnormalities may require antimicrobial prophylaxis, which may be associated with adverse effects, such as intolerability or an increased risk of microbial resistance. Conclusion: The resistance pattern of uropathogens should be considered prior to initiating therapy. Controlled trials with large samples are needed to compare the treatment duration of various antimicrobial regimens and the specific role of prophylactic antimicrobials.

Multidrug- and Carbapenem-Resistant Pseudomonas aeruginosa in Children, United States, 1999-2012

BACKGROUND

Pseudomonas aeruginosa is a common cause of healthcare-associated infection. Multidrug-resistant (MDR) (>3 classes) and carbapenem-resistant (CR) P aeruginosa are significant threats globally. We used a large reference-laboratory database to study the epidemiology of P aeruginosa in children in the United States.

METHODS

Antimicrobial susceptibility data from the Surveillance Network were used to phenotypically identify MDR and CR P aeruginosa isolates in children aged 1 to 17 years between January 1999 and July 2012. Logistic regression analysis was used to calculate trends in the prevalence of MDR and CR P aeruginosa. Isolates from infants (<1 year old) and patients with cystic fibrosis were excluded.

RESULTS

Among the isolates tested, the crude proportion of MDR P aeruginosa increased from 15.4% in 1999 to 26% in 2012, and the proportion of CR P aeruginosa increased from 9.4% in 1999 to 20% in 2012. The proportion of both MDR and CR P aeruginosa increased each year by 4% (odds ratio [OR], 1.04 [95% confidence interval (CI), 1.03-1.04] and 1.04 [95% CI, 1.04-1.05], respectively). In multivariable analysis, both MDR and CR P aeruginosa were more common in the intensive care setting, among children aged 13 to 17 years, in respiratory specimens, and in the West North Central region. In addition, resistance to other antibiotic classes (aminoglycosides, fluoroquinolones, cephalosporins, and piperacillin-tazobactam) often used to treat P aeruginosa increased.

CONCLUSIONS

Rates of MDR and CR P aeruginosa infection in children are rising nationally. Aggressive prevention strategies, including instituting antimicrobial stewardship programs in pediatric settings, are essential for combating antimicrobial resistance.

Clinical risk factors, bacterial aetiology, and outcome of urinary tract infection in children hospitalized with diarrhoea in Bangladesh

Urinary tract infection (UTI) is common in children aged <5 years with diarrhoea, but little is known about risk factors, aetiology and outcome of such children. We aimed to evaluate these knowledge gaps of UTI in children aged <5 years with diarrhoea. We enrolled all children aged <5 years with diarrhoea admitted to Dhaka Hospital of the International Centre for Diarrhoeal Disease Research, Bangladesh, between May 2011 and April 2013, who had history of fever (⩾38 °C) and obtained a urine sample for culture. Diarrhoea with UTI (confirmed by culture) constituted cases (n = 26) and those without UTI constituted controls (n = 78). Threefold controls were randomly selected. The case-fatality rate was comparable in cases and controls (4% vs. 1%, P = 0·439). Escherichia coli (69%) and Klebsiella (15%) were the most commonly isolated pathogens. Persistent diarrhoea, pneumonia and prior antibiotics use were identified as risk factors for UTI in logistic regression analysis (P < 0·05 for all). Thus, children with diarrhoea presenting with persistent diarrhoea, pneumonia, and prior antibiotic use should be investigated for UTI for their prompt management that may reduce morbidity.

Urinary tract infections caused by Pseudomonas aeruginosa among children in Southern Poland: Virulence factors and antibiotic resistance

OBJECTIVE

The aim of this study was to analyze antibiotic resistance and virulence patterns in Pseudomonas aeruginosa (PAR) isolates from urinary tract infections among children in Southern Poland.

MATERIALS AND METHODS

This study comprised consecutive, non-repetitive PAR isolates sent from two collaborative laboratories. The study group consisted of children aged up to 17 years from Southern Poland with culture-proven PAR UTIs. Relevant information about patients with UTIs, such as age, sex, and type of infection (polymicrobial or monomicrobial), was collected. Isolates were screened for major virulence factors found in uropathogenic PAR strains. Multidrug-resistant (MDR) strains were defined as strains not susceptible to one antimicrobial in at least three different antimicrobial classes. Extensively drug resistant (XDR) strains were defined as strains susceptible to no more than two antimicrobial classes.

RESULTS

The total prevalence of PAR UTIs was 2.1%, and in children <5 years of age it was 3.0%. A total of 26 isolates was tested: 21 from outpatients and five from inpatients. Most infections (80.8%) occurred in children ≤ 4 years of age. The most prevalent virulence gene was exoY (96.2%). The prevalence of other effector proteins was 88.5% for exoT, 92.3% for exoS, and 19.2% for exoU. The gene for LasB was present in 80.8% of isolates; the gene for AprA in 61.5%; the gene for PilA in 19.2%; and the gene for PilB was not detected. The PAR isolates were generally susceptible to beta-lactam and aminoglycoside antimicrobials. All isolates were also susceptible to colistin. A large proportion of isolates were resistant to carbapenems and fluoroquinolones (Fig. 1). No significant differences were found in antimicrobial resistance between males and females or inpatients and outpatients (p > 0.05 for all tested antimicrobials), or in antimicrobial resistance between younger (≤ 5 years old, n = 21) and older (> 5 years old, n = 5) children (p > 0.05 for all tested antimicrobials). Two isolates were classified as XDR and none as MDR. The EDTA test yielded one MBL-positive isolate (3.8%), from a 17-year-old patient in home care. No isolates with genes for the KPC, IMP, or VIM were identified.

CONCLUSION

As data on UTIs in children with Pseudomonas etiology are scarce, this paper provides useful information for clinicians and allows for comparison between Poland and other countries. Our findings have important implications for clinicians treating UTIs empirically, because the success of empiric treatment is based on knowledge of pathogen antimicrobial susceptibility patterns.

Escherichia coli virulence patterns may help to predict vesicoureteral reflux in paediatric urinary tract infections

AIM

Ultrasound and biological tools are used to predict high-grade vesicoureteral reflux, but other markers are needed to better select patients who need voiding cystography. Our aim was to determine whether studying Escherichia coli virulence factors would help to predict vesicoureteral reflux in patients with their first acute pyelonephritis.

METHODS

We included children presenting with E. coli-related acute pyelonephritis or cystitis. Vesicoureteral reflux was assessed by voiding cystography. Virulence factors were identified by multiplex polymerase chain reaction. Statistical analysis was performed using logistic regression and the mean c-statistic test.

RESULTS

We included 198 patients: 30 with cystitis and 168 with acute pyelonephritis, including 46 with vesicoureteral reflux. High-grade reflux was associated with acute pyelonephritis caused by the E. coli lacking virulence factors papGII (82% versus 47%, p < 0.001) or papC (85% versus 53%, p < 0.001) or belonging to phylogenetic group A or B1. When we added genetic data (lack of papGII, fyuA and phylogenetic groups) to classical predictors of vesicoureteral reflux (ultrasound examination, gender, age), the ability to predict high-grade reflux increased, with the c-statistic rising from 0.88 to 0.93.

CONCLUSION

Bacterial virulence factors and clinical factors helped to predict high-grade reflux and may help to avoid unnecessary voiding cystographies.

High prevalence and antimicrobial resistance of urinary tract infection isolates in febrile young children without localizing signs in Taiwan

BACKGROUND

Antimicrobial susceptibility and prevalence of pediatric urinary tract infection (UTI) is very useful for pediatricians in selecting effective antibiotics in time to improve outcomes in patients. This study aimed to determine the prevalence rate, bacterial distribution, and antimicrobial susceptibility of UTI in febrile young children at a teaching hospital in northern Taiwan.

METHODS

From January 2011 to December 2011, all urinary isolates from suspected cases of UTI in febrile young children aged from 1 day to 36 months visiting the Pediatric Emergency Room of Chang Gung Children's Hospital, Taoyuan, Taiwan were identified by conventional methods. Antibiotic susceptibility was determined according to the Clinical and Laboratory Standards Institute.

RESULTS

A total of 5470 (78%) from 7009 eligible children were enrolled in the study, and 619 (11.3%) had a diagnosis of UTI. The most prevalent bacterium was Escherichia coli (68%) followed by Klebsiella pneumoniae (8.1%) and Proteus mirabilis (6.8%). Ampicillin, piperacillin, and trimethoprim-sulfamethoxazole (TMP-SMX) showed a higher resistance rate in the three predominant bacteria. All tested bacteria showed higher resistance to ampicillin (79.3%) and TMP-SMX (44.1%), and lower resistance to cefazolin (17.7%) and gentamicin (13.0%). Fourteen percent of the isolates produced extended spectrum β-lactamase (ESBL), among which 93.33% were E. coli isolates.

CONCLUSION

The overall prevalence of UTI in this study was higher than previously reported in febrile children. Higher antimicrobial resistance was found in ampicillin and TMP-SMX. Among commonly used antibiotics, cefazolin and gentamicin are recommended to treat UTI in febrile children aged < 3 years without localizing signs.

The epidemiology of bacteriuria and candiduria in critically ill patients

An observational study was conducted to describe the epidemiology of bacteriuria and candiduria in the intensive care unit (ICU), and the occurrence of blood stream infection (BSI) associated with ICU-acquired positive urine culture. Between 2006 and 2011, 444 episodes of either bacteriuria or candiduria defined by positive urine culture (microorganisms ⩾105 c.f.u./ml) occurred in 406 patients. Three hundred and seventy-seven (85%) were hospital-acquired including 221 which were ICU-acquired (6·4 ± 0·8 episodes/1000 ICU days). Escherichia coli was the most common bacteria of both community- and ICU-acquired bacteriuria/candiduria (49·2% and 29%, respectively). Candida spp. represented 55% (129/236) of pathogens responsible for ICU-acquired positive urine cultures. Patients with ICU-acquired candiduria had greater illness severity at ICU admission than those with ICU-acquired bacteriuria (APACHE III score 79 ± 25 vs. 66 ± 31, P = 0·0015). BSI associated with ICU-acquired positive urine culture occurred in 0·15/1000 ICU days and was more often due to Candida. In this study, Candida was the most common pathogen responsible for ICU-acquired positive urine cultures and illness severity was a risk factor for candiduria in the study population.

Antimicrobial susceptibilities and clinical characterization of Pseudomonas aeruginosa isolates from urinary tract infections

INTRODUCTION

Pseudomonas aeruginosa is a uropathogen that is mainly involved in nosocomial infection. The aim of this study was to analyze the antimicrobial susceptibilities and clinical characterization of P. aeruginosa isolates from urinary tract infections (UTIs).

MATERIALS AND METHODS

The study collected all P. aeruginosa UTI strains from a hospital in Chongqing, China, from January 1st, 2010 to December 31st, 2011. The antibiotic susceptibilities of the P. aeruginosa isolates were analyzed using the agar dilution method and the genotypes were assessed using random amplification of polymorphic DNA-PCR (RAPD-PCR). The clinical characteristics of the patients with UTIs were collected from the hospital information systems, and significance was analyzed using the proportion test.

RESULTS

A total of 2,778 episodes of culture-proven UTIs were used in the study. There were 198 infections (7.1%) caused by P. aeruginosa. P. aeruginosa strains were highly resistant to most drugs tested. The RAPD-PCR data revealed that the 198 P. aeruginosa infections had 82 different genotypes. Antibacterial use, previous UTI, urinary tract catheter and urinary tract operation were found to be risk factors for the development of UTIs.

CONCLUSIONS

P. aeruginosa is the second most common UTI pathogen in our hospital. We should closely monitor patients with risk factors for P. aeruginosa infection.

Reduced bacterial colonisation of the glans penis after male circumcision in children--a prospective study

OBJECTIVE

The aim of this prospective study was to evaluate the effect of male circumcision on the bacterial colonisation of the glans penis in children.

PATIENTS AND METHODS

244 males were included in this study. The study group consisted of 143 boys admitted for circumcision between August 2009 and July 2010. Periurethral swabs were taken preoperatively and one week postoperatively. The control group included 101 boys without phimosis, in which only one swab was taken. Patients were subgrouped according to age below and above five years. Bacterial cultures were analysed, results were categorized by non-uropathogenic and uropathogenic bacteria, and compared within and between groups.

RESULTS

Patients in both control group and study group before circumcision showed significant bacterial colonisation (>98%), involving known uropathogenic bacteria in over 86%. After circumcision, bacterial colonisation dropped from 100% to 86.3% (p < 0.005) in boys younger than five years and from 98.57% to 77.14% (p < 0.001) in those aged five or above, respectively. Moreover, the fraction of uropathogenic bacteria decreased significantly.

CONCLUSION

Male circumcision significantly reduces the bacterial colonisation of the glans penis with regard to both non-uropathogenic and uropathogenic bacteria.

A one-year prospective study on the antibiotic resistance of E. coli strains isolated in urinary specimens of children hospitalized at the University Pediatric Medical Center in Novi Sad, Serbia

PURPOSE

Urinary tract infections (UTIs), the most common serious bacterial infections in children, are frequently caused by Escherichia coli. The purpose of this study was to investigate E. coli resistance/multidrug resistance to antibiotics most frequently used for UTIs.

METHODS

Children 0-18 years of age, hospitalized at the University Pediatric Hospital in Novi Sad, Serbia, were included in a 1-year observational prospective study. The microbiological analysis was performed using the standard Kirby-Bauer disk diffusion method. The results were analyzed using WHONET 5.4 software.

RESULTS

E. coli was isolated from 61.7 % of positive urine specimens. In general, higher average E. coli antibiotic resistance was found in infants and toddlers compared to children and adolescents (33.4 vs. 25.0 %) (p < 0.0001). Furthermore, it was observed that the average resistance to all the tested antibiotics was higher in boys than in girls (37.0 vs. 25.1 %) (p < 0.0001). E. coli was highly susceptible to piperacillin/tazobactam (>93.1 %), amikacin (86.3 %), quinolones (>75.0 %), and penems (>96.6 %). The prevalence of multiresistant E. coli strains was significantly higher in infants and toddlers (72.3 vs. 36.8 %) (p < 0.0001).

CONCLUSIONS

E. coli, a common cause of UTIs in children admitted to pediatric hospitals, is highly resistant/multidrug-resistant to commonly used antibiotics. Higher average resistance is found in infants and toddlers than in children and adolescents, as well as in boys compared to girls. These findings are important for the regional empiric therapy of UTIs and call for actions to decrease E. coli antibiotic resistance.

Community-acquired enterococcal urinary tract infections in hospitalized children

The objectives of this study were to characterize community-acquired (CA) enterococcal urinary tract infections (UTIs) in a tertiary pediatric center and to determine risk factors for their occurrence, their association with renal abnormalities, their antibiotic susceptibility profile, and the appropriateness of the empiric antibiotic treatment, in comparison to those of Gram-negative UTIs. In a 5-year prospective clinical and laboratory study, we found that enterococcal UTIs caused 6.2% (22/355) of culture-proven CA UTIs. Compared with Gram-negative UTI, enterococcal UTI was associated with male predominance, higher rates of underlying urinary abnormalities (70 vs. 43.7%; p = 0.03) and inappropriate empiric antibiotic therapy (22 vs. 5.6%; p = 0.02), and mainly vesicoureteral reflux (53% of cases). This study highlights the importance of early detection of CA enterococcal UTIs because of their association with underlying urinary abnormalities and a high rate of inappropriate empiric antibiotic therapy. Renal imaging is recommended for children with enterococcal UTIs; Gram stain is suggested in selected cases to detect Gram-positive cocci for early diagnosis of enterococcal UTIs and initiation of appropriate antibiotics.

Common childhood bacterial infections

Children with infectious diseases are commonly encountered in primary care settings. Identification of the subset of patients with bacterial infections is key in guiding the best possible management. Clinicians frequently care for children with infections of the upper respiratory tract, including acute otitis media, otitis externa, sinusitis, and pharyngitis. Conjunctivitis is not an uncommon reason for office visits. Bacterial pneumonia, urinary tract infections, and gastroenteritis are regularly seen. Over the last decade, a growing number of children have had infections of the skin and soft tissue, driven by the increased prevalence of infections caused by methicillin-resistant Staphylococcus aureus. The following review addresses the epidemiology and risk factors for specific infections and examines the clinical presentation and selection of appropriate diagnostic methods in such conditions. Methods to prevent these bacterial infections and recommendations for follow-up are suggested. Management of these infections requires that antimicrobial agents be used in a judicious manner in the outpatient setting. Such antibiotic therapy is recommended using both available clinical evidence and review of disease-specific treatment guidelines.

Prophylactic cefdinir for pediatric cases of complicated urinary tract infection

BACKGROUND

This study evaluated the effect of prophylactic cefdinir (3 mg/kg given once daily) for the prevention of recurrent and complicated urinary tract infections (UTI) in pediatric patients.

METHODS

The study included 14 infants who were observed for at least 6 months following the first signs of infection (eight boys, six girls; mean age at admission [± SD]: 6.2 [± 7.4] months). Twelve patients had vesico-ureteric reflux (grade I, two; grade II, three; grade III, six; grade IV, one), and two patients had ureteropelvic junction stenosis.

RESULTS

No patients discontinued medication due to diarrhea or other adverse drug reactions. The patients had a 6-month recurrence-free rate of 93% (13/14); only one patient had recurrent UTI. The mean urinary cefdinir concentration was 16.3 [± 11.7]µg/mL; there was considerable variability among individual measurements, even though the samples were collected at similar intervals after drug intake (mean 18.00 [± 2.63] h after dose). However, the lowest measured urinary cefdinir concentration (1.16 µg/mL) was sufficient to eradicate Escherichia coli, one of the most significant causes of UTI. Fecal cultures, obtained at monthly clinic visits during the observation period, indicated that the patients' E. coli strains were very sensitive to cefdinir. No patients were infected with Pseudomonas aeruginosa or other non-fermenting Gram-negative bacilli or fungi.

CONCLUSIONS

These results show that cefdinir given 3 mg/kg once daily is very effective and safe for preventing recurrent complicated UTI in infants.

[Assessing the usefulness of a permanently opened clinical microbiology laboratory]

Since 2005, the clinical microbiology laboratory of the Angers teaching hospital has implemented after hours service requiring the overnight presence of a technician specialized in bacteriology. During that time, bacterial identifications and antibiotic susceptibility testing to antimicrobial agents can be performed for critical samples.

OBJECTIVES

The authors wanted to evaluate the impact of the after-hours service on the decrease of delay from sampling to results, and from sampling to the implementation of an appropriate antimicrobial therapy. A therapy could be initiated, changed for more efficient agents, or changed to narrower-spectrum agents (major benefits).

METHODS

A 4-month prospective study was made. All samples for which identification and/or susceptibility testing were performed during after-hours service (continued analyses) were included in the study. Delays observed were compared with theoretical delays estimated in the absence of the after-hours service.

RESULTS

A minimum 24 hour-decrease of the delay for results was observed for 97 % of the 430 samples included. Overall, a major benefit was obtained for more than 25 % of the analyses, representing a cumulated 111-day benefit in days of efficient treatments and a cumulated 27-day benefit in days of prescription of narrower-spectrum agents.

DISCUSSION

This organization, unique in French hospitals, is directly related to the improvement of antimicrobial treatments, like antibiotic practice guidelines or infection disease specialists. It was evaluated as a relevant strategy, potentially cost saving, with a significant impact on both the efficiency of treatments and microbial ecology.