Nosocomial infections and multidrug-resistant bacterial organisms in the pediatric intensive care unit

Clinical Management of a Pandrug-Resistant OXA-48 Klebsiella pneumoniae Infection in the Pediatric Intensive Care Unit

Background: Carbapenem-resistant Klebsiella pneumoniae (CRKP) is one of the serious forms of health care-associated infection. Pan-drug resistant (PDR) CRKP infections can cause severe infections. Mortality and treatment costs in the pediatric intensive care unit (PICU) are high. This study aims to share our experience regarding the treatment of oxacillinase (OXA)-48-positive PDR-CRKP infection in our 20-bed tertiary PICU with isolated rooms and 1 nurse for every 2-3 patients. Methods: Patient demographic characteristics, underlying diseases, previous infections, source of infection PDR-CRKP, treatment modalities, measures used, and outcomes were recorded. Findings: Eleven patients (eight men and three women) were found to have PDR OXA-48-positive CRKP. Because of the simultaneous detection of PDR-CRKP in three patients and the rapid spread of the disease, it was classified as a clinical outbreak, and strict infection control measures were taken. Combination therapy with double carbapenemase (meropenem and imipenem), amikacin, colistin, and tigecycline was used for treatment. The mean duration of treatment and isolation was 15.7 and 65.4 days, respectively. No treatment-related complication was observed, only one patient died, and the mortality rate was 9%. Conclusions: This severe clinical outbreak can be successfully treated with effective treatment with combined antibiotics and strict adherence to infection control measures. ClinicalTrial.gov ID: 28/01/2022 - 1/5.

Factors associated with multidrug-resistant bacteria in healthcare-associated infections: a pediatric intensive care unit case-control study

OBJECTIVE

To investigate the prevalence of factors related to healthcare-associated infections, caused by multidrug-resistant bacteria, in a pediatric intensive care unit.

METHODS

A retrospective case-control study conducted from January 1, 2007 to December 31, 2018, in São Paulo (SP), Brazil. The study was carried out at the pediatric intensive care unit of a high-complexity, tertiary care general hospital. The study included patients aged 1 month to 19 years, admitted to the pediatric intensive care unit, diagnosed as healthcare-associated infections.

RESULTS

There was significant evidence of infection by multidrug-resistant bacteria associated with immunosuppressed patients (p<0.001), in whom the likelihood of multidrug-resistant bacteria infection was estimated to be nine-fold higher than among non-immunosuppressed patients (OR 8.97; 95%CI 2.69-29.94). In the analysis of multiple logistic regression model, we observed that immunosuppressed patients had an 8.5-fold higher chance of multidrug-resistant bacteria infection when compared to non-immunosuppressed patients (OR 8.48; 95%CI 2.54-28.35; p=0.001). There is evidence of association between the Case Group and presence of Gram-positive (p=0.007), coagulase-negative Staphylococcus (p<0.001), and Gram-negative (p=0.041) microorganisms.

CONCLUSION

The immunocompromised-state variable is a factor related to healthcare-associated infections caused by multidrug-resistant bacteria, and the Case Group presented higher proportions of Gram-positive microorganisms and coagulase-negative Staphylococcus.

The impact of monitoring software on antimicrobial management in a pediatric intensive care unit

INTRODUCTION

Antimicrobial stewardship programs are necessary practices to combat resistance in hospital infections. However, studies frequently cite the scarcity of technological resources as an obstacle to the comprehensive development of ASPs.

OBJECTIVES

The aim of the study was to assess the impact of monitoring software on reducing antibiotic consumption and reducing resistance in a pediatric intensive care unit.

METHODS

We conducted an analytical longitudinal study during the period January 1, 2007, to December 31, 2018, in the pediatric intensive care unit of a high-complexity tertiary general hospital in Brazil.

RESULTS

In the period after the implementation of software, we observed decreases in total antimicrobial consumption (P = .037). Regarding Enterobacterales, we observed a decrease in the proportion of antimicrobial resistance of first and second-generation cephalosporin classes (P = .041) and third and fourth-generation cephalosporins (P = .028). There was a decrease in the proportion of resistance of nonfermenting gram-negative bacilli to aminoglycoside scans (P = .016). We also observed evidence of a decrease in the proportion of resistance of Staphylococcus aureus agents to oxacillin (P < .001).

CONCLUSIONS

The monitoring software reduced the total consumption of antimicrobials and decreased the proportion of resistance, therefore demonstrating its importance in controlling the development of multidrug-resistant bacteria.

Incidence of emerging multidrug-resistant organisms and its impact on the outcome in the pediatric intensive care

Background

Healthcare-associated infections (HCAI) are a worldwide threat in intensive care units particularly in the pediatric intensive care units with a major cause of morbidity and mortality among this age group. The aim of the study is to determine the prevalence and risk factors predisposing to multidrug-resistant organisms (MDROs) infections among pediatric intensive care unit (PICU) patients at Ain Shams Pediatric University Hospitals as well as determining mortality and morbidity rates along with the length of stay at PICU.

Results

Culture results revealed that of the 282 patients evaluated, only 26 (9.2%) were MDROs (half of the affected patients had Acinetobacter species (50%) and the rest of them were free, 256 (90.8%). Our study revealed that the majority of MDROs were isolated from sputum in more than half of the patients 19/32 (59.3%) followed by whole blood in 10/32 (31.2%) and urine in 3/32 (9.4%). Pulmonary system was the most common affected site and was mainly colonized by MDR Acinetobacter (71.4%) followed by MDR Klebsiella (41.6%). Regarding MDR risk factors in our PICU, multivariate logistic regression analyses showed significant relationship between MDROs and age under 1 year (odds ratio [OR] 2.4554; 95% confidence interval [95% CI] (1.072–5.625); p = 0.043) and underlying pulmonary disease (OR 2.417; 95% CI (1.014–5.761); p = 0.592). A statistically significant higher mortality was detected in patients colonized with MDROs 9/26 (34.6%) versus MDROs non-colonized patients 32/256 (12.5%) [P=0.002]. Moreover, MDROs infection has negative significant risk with discharged patients ([OR] 0.269; [95% CI] (0.111–0.656); p = 0.002). Additionally, patients infected with MDROs did have significantly greater PICU stay than those non-infected [median (IQR), 16.5 (10.7–22), 5 (4–8), P=0.00] and have longer ventilation [median (IQR), 15.5 (10–18), 3 (2–10), P=0.00].

Conclusion

Prevalence of MDROs (9.2%) was low among PICU cases at Ain Shams University Hospitals. Most common MDROs were Acinetobacter and Klebsiella followed by pseudomonas species. The frequency of gram-negative organisms is much more common than gram-positive organisms. An increasing rate of antimicrobial resistance with increasing mortality and morbidity among PICU patients is observed worldwide; even for new categories, so, strict infection control programs should be implemented.

What we can do? The risk factors for multi-drug resistant infection in pediatric intensive care unit (PICU): a case-control study

Background

The risk factors for multi-drug resistant infection (MDRI) in the pediatric intensive care unit (PICU) remain unclear. It’s necessary to evaluate the epidemiological characteristics and risk factors for MDRI in PICU, to provide insights into the prophylaxis of MDRI clinically.

Methods

Clinical data of 79 PICU children with MDRI were identified, and 80 children in PICU without MDRI in the same period were selected as control group. The related children’s characteristics, clinical care, microbiologic data, treatments provided, and outcomes of the patients with were reviewed and collected. Univariate and multivariate logistic regression analyses were performed to identify the potential risks of MDRI in PICU.

Results

Of the diagnosed 79 cases of MDRI, there were28 cases of CR-AB, 24 cases of MRSA, 22 cases of PDR-PA,3 cases of VRE and 2 cases of CRE respectively. Univariate analyses indicated that the length of PICU stay, the duration of mechanical ventilation > 5 days, parenteral nutrition, coma, urinary catheter indwelling, invasive operation, 2 or more antibiotics use were associated with MDRIs (all p < 0.05); The logistic multiple regression analyses indicated that coma, parenteral nutrition, 2 or more antibiotics use and the duration of mechanical ventilation > 5 days were independent risk factors associated with MDRI (all p < 0.05).

Conclusions

This present study has identified several potentially modifiable risk factors for MDRI in PICU, it’s conducive to take appropriate measures targeting risk factors of MDRI for health care providers to reduce MDRI.

Pediatric Sepsis Update: How Are Children Different?

BACKGROUND

Although there are some commonalities between pediatric and adult sepsis, there are important differences in pathophysiology, clinical presentation, and therapeutic approaches. The recognition and diagnosis of sepsis is a significant challenge in pediatric patients as vital sign aberrations and examination findings are often subtle as compared to those observed in adults. Gaps in knowledge that have been studied in depth in adult sepsis are still being investigated in pediatric patients such as best practices in ventilation, invasive monitoring, and resuscitation.

DISCUSSION

In this review, we address key differences in the etiology, presentation, resuscitation, and outcomes of sepsis in children compared with adults.

Pathogen Distribution and Antimicrobial Resistance Among Pediatric Healthcare-Associated Infections Reported to the National Healthcare Safety Network, 2011-2014

OBJECTIVE To describe pathogen distribution and antimicrobial resistance patterns for healthcare-associated infections (HAIs) reported to the National Healthcare Safety Network (NHSN) from pediatric locations during 2011-2014. METHODS Device-associated infection data were analyzed for central line-associated bloodstream infection (CLABSI), catheter-associated urinary tract infections (CAUTI), ventilator-associated pneumonia (VAP), and surgical site infection (SSI). Pooled mean percentage resistance was calculated for a variety of pathogen-antimicrobial resistance pattern combinations and was stratified by location for device-associated infections (neonatal intensive care units [NICUs], pediatric intensive care units [PICUs], pediatric oncology and pediatric wards) and by surgery type for SSIs. RESULTS From 2011 to 2014, 1,003 hospitals reported 20,390 pediatric HAIs and 22,323 associated pathogens to the NHSN. Among all HAIs, the following pathogens accounted for more than 60% of those reported: Staphylococcus aureus (17%), coagulase-negative staphylococci (17%), Escherichia coli (11%), Klebsiella pneumoniae and/or oxytoca (9%), and Enterococcus faecalis (8%). Among device-associated infections, resistance was generally lower in NICUs than in other locations. For several pathogens, resistance was greater in pediatric wards than in PICUs. The proportion of organisms resistant to carbapenems was low overall but reached approximately 20% for Pseudomonas aeruginosa from CLABSIs and CAUTIs in some locations. Among SSIs, antimicrobial resistance patterns were similar across surgical procedure types for most pathogens. CONCLUSION This report is the first pediatric-specific description of antimicrobial resistance data reported to the NHSN. Reporting of pediatric-specific HAIs and antimicrobial resistance data will help identify priority targets for infection control and antimicrobial stewardship activities in facilities that provide care for children. Infect Control Hosp Epidemiol 2018;39:1-11.

Is there a role for clowns in paediatric intensive care units?

Hospital clowning is a programme in healthcare facilities involving visits from specially trained actors. In the paediatric intensive care unit (PICU), clowning may appear inappropriate and less intuitive. The patient could appear too ill and/or sedated, the environment too crowded or chaotic and the parents too stressed. Relying on our experience with professionally trained clowns both in France and Canada, the purpose of this article is to offer a model for hospital clowning and to suggest standards of practice for the implementation of clowning in PICUs. In this work, we provide a framework for the implementation of clown care in the PICU, to overcome the challenges related to the complex technical environment, the patient's critical illness and the high parental stress levels. Regardless of the specifics of the PICU, our experience suggests that professional clown activity is feasible, safe and can offer multiple benefits to the child, his/her parents and to hospital personnel. Due to the specific challenges in the PICU, clowns must be educated and prepared to work in this highly specialised environment. We stress that prior to clowning in a PICU, professional performers must be highly trained, experienced, abide by a code of ethics and be fully accepted by the treating healthcare team.

First Report of Group CTX-M-9 Extended Spectrum Beta-Lactamases in Escherichia coli Isolates from Pediatric Patients in Mexico

The aim of this study was to identify the presence of group CTX-M-9 extended spectrum beta-lactamases (ESBL) in clinical Escherichia coli isolates from pediatric patients. A total of 404 non-repeated positive ESBL E. coli isolates were collected from documented clinical infections in pediatric patients over a 2-year period. The identification and susceptibility profiles were determined using an automated system. Isolates that suggested ESBL production based on their resistance profiles to third and fourth generation cephalosporin and monobactam were selected. ESBL production was phenotypically confirmed using a diffusion method with cefotaxime and ceftazidime discs alone and in combination with clavulanic acid. blaESBL gene identification was performed through PCR amplification and sequencing. Pulsed Field Gel Electrophoresis (PFGE) and Multilocus Sequence Typing (MLST) were performed to establish the clonal relationships of the E. coli isolates. CTX-M-9-type ESBLs were detected in 2.5% of the isolates. The subtypes corresponded to blaCTX-M-14 (n = 4) and blaCTX-M-27 (n = 6). Additionally, coexistence with other beta-lactamases was observed. A clonal relationship was established in three isolates; the rest were classified as non-related. We found seven different sequence type (ST) in CTX-M-9- producing E. coli isolates. ST38 was the most frequent. This study is the first report in Mexico to document the presence of group CTX-M-9 ESBLs in E. coli isolates from pediatric patients.

In Vitro Inhibition of Klebsiella pneumoniae by Lactobacillus delbrueckii Subsp. delbrueckii LDD01 (DSM 22106): An Innovative Strategy to Possibly Counteract Such Infections in Humans?

GOALS

To determine the in vitro antimicrobial activity of selected Lactobacillus strains isolated from the feces of healthy humans against Klebsiella pneumoniae.

BACKGROUND

Klebsiella is ubiquitous in nature and may colonize the skin, the pharynx, or the gastrointestinal tract of humans. Despite the widespread use of antibiotic molecules with a broad spectrum in hospitalized patients, an increased overall load of klebsiellae as well as the subsequent development of multidrug-resistant strains able to synthesize extended-spectrum beta-lactamase have been registered. These strains are particularly virulent, express capsular-type K55, and have a considerable ability to propagate.

STUDY

The 4 strains Lactobacillus paracasei LPC01 (CNCM I-1390), Lactobacillus rhamnosus LR04 (DSM 16605), Bifidobacterium longum B2274 (DSM 24707), and Lactobacillus delbrueckii subsp. delbrueckii LDD01 (DSM 22106) were tested. The analysis was performed using both a disc-diffusion assay and the broth-dilution procedure, also including an evaluation of the supernatants obtained from a fresh broth culture of each bacterium.

RESULTS

L. delbrueckii subsp. delbrueckii LDD01 demonstrated the best inhibitory results among all the tested strains. The antibacterial activity of the supernatant was retained even after treatment with α-amylase and neutralization with NaOH 1N, thus suggesting the protein structure of the inhibitory molecule. In contrast, it was completely lost after treatment with proteinase K.

CONCLUSIONS

Overall results suggest that the inhibitory effect of L. delbrueckii subsp. delbrueckii LDD01 should be attributed to the production of a bacteriocin. This strain may be prospectively useful for strengthening probiotic formulations and possibly counteract infections by K. pneumoniae in humans.

Healthcare-Associated Infections in Pediatric and Neonatal Intensive Care Units: Impact of Underlying Risk Factors and Antimicrobial Resistance on 30-Day Case-Fatality in Italy and Brazil

OBJECTIVES To describe trends in the epidemiology of healthcare-associated Infections (HAIs) in pediatric/neonatal intensive care units (ICUs) and to evaluate risk factors and impact of multidrug resistance in children admitted to ICUs. DESIGN Multicenter, retrospective, cohort study with a nested case-control study conducted from January 1, 2010, through December 31, 2014. SETTING Three tertiary care pediatric hospitals in Italy and Brazil with a total of 103 ICU beds. PATIENTS Inclusion criteria were admission to ICU during the study period, age at onset less than 18 years, and microbiologically confirmed HAI. RESULTS A total of 538 HAIs in 454 children were included; 93.3% of patients had comorbidities. Bloodstream infections were the leading pattern (45.4%). The cumulative incidence of HAI was 3.6/100 ICU admissions and the crude 30-day fatality rate was 5.7/1,000 admissions. The most frequently isolated pathogens were Enterobacteriaceae, followed by Pseudomonas aeruginosa and Staphylococcus aureus. Forty-four percent of isolates were multidrug-resistant (MDR). Two multivariate logistic regressions were performed. Factors independently associated with an MDR-HAI were country, previous antibiotics, transplantation, major surgery, and colonization by an MDR strain. Factors independently associated with 30-day case fatality were country, previous transplantation, fungal infection, bloodstream infection, lower respiratory tract infection, and infection caused by MDR strains. CONCLUSIONS Infection control and prevention can limit the spread of MDR strains and improve outcomes. Targeted surveillance programs collecting neonatal and pediatric HAI/bloodstream infection data and outcomes would allow global benchmarking. The next step is to identify methods to monitor key HAIs and integrate these into affordable intervention programs. Infect Control Hosp Epidemiol 2016;1-8.

Acinetobacter baumannii infections in a South African paediatric intensive care unit

OBJECTIVES

To describe and compare characteristics and outcomes of patients colonized or infected with Acinetobacter baumannii (cases) to a control group.

METHODS

A retrospective case-controlled study of patients admitted to a South African paediatric intensive care unit (PICU) between January and December 2010.

RESULTS

Acinetobacter baumannii was isolated in 194 patients. Mortality was similar between cases (9.3%) and controls (9.8%). Median duration of PICU stay and mechanical ventilation in cases vs. controls was 10 vs. 2 (p < 0.0001) and 9 vs. 1 days (p < 0.0001), respectively. Admission diagnosis of traumatic brain injury [adjusted odds ratio (OR): 5.6, 95% CI: 1.2-27.0; p = 0.03] and duration of mechanical ventilation (adjusted OR: 1.4, 95% CI: 1.3-1.5; p < 0.0001) were independently associated with A. baumannii aquisition.

CONCLUSION

Acinetobacter baumannii acquisition was common and associated with increased morbidity, but not increased mortality.

Fever after maxillofacial surgery: a critical review

PURPOSE

The aim of this paper is to review the pathophysiology of thermoregulation mechanism, various causes of fever after maxillofacial surgery and the different treatment protocols advised in the literature.

DISCUSSION

Fever is one of the most common complaints after major surgery and is also considered to be an important clinical sign which indicates developing pathology that may go unnoticed by the clinician during post operative period. Several factors are responsible for fever after the maxillofacial surgery, inflammation and infection being the commonest. However, other rare causes such as drug allergy, dehydration, malignancy and endocrinological disorders, etc. should be ruled out prior to any definite diagnosis and initiate the treatment. Proper history and clinical examination is an essential tool to predict the causative factors for fever. Common cooling methods like tepid sponging are usually effective alone or in conjunction with analgesics to reduce the temperature.

CONCLUSION

Fever is a common postoperative complaint and should not be underestimated as it may indicate a more serious underlying pathology. A specific guideline towards the management of such patients is necessary in every hospital setting to ensure optimal care towards the patients during post operative period.

Endoscopic retrograde cholangiopancreatography-associated AmpC Escherichia coli outbreak

BACKGROUND

We identified an outbreak of AmpC-producing Escherichia coli infections resistant to third-generation cephalosporins and carbapenems (CR) among 7 patients who had undergone endoscopic retrograde cholangiopancreatography at hospital A during November 2012-August 2013. Gene sequencing revealed a shared novel mutation in a bla CMY gene and a distinctive fumC/ fimH typing profile.

OBJECTIVE

To determine the extent and epidemiologic characteristics of the outbreak, identify potential sources of transmission, design and implement infection control measures, and determine the association between the CR E. coli and AmpC E. coli circulating at hospital A.

METHODS

We reviewed laboratory, medical, and endoscopy reports, and endoscope reprocessing procedures. We obtained cultures from endoscopes after reprocessing as well as environmental samples and conducted pulsed-field gel electrophoresis and gene sequencing on phenotypic AmpC isolates from patients and endoscopes. Cases were those infected with phenotypic AmpC isolates (both carbapenem-susceptible and CR) and identical bla CMY-2, fumC, and fimH alleles or related pulsed-field gel electrophoresis patterns.

RESULTS

Thirty-five of 49 AmpC E. coli tested met the case definition, including all CR isolates. All cases had complicated biliary disease and had undergone at least 1 endoscopic retrograde cholangiopancreatography at hospital A. Mortality at 30 days was 16% for all patients and 56% for CR patients. Two of 8 reprocessed endoscopic retrograde cholangiopancreatography scopes harbored AmpC that matched case isolates by pulsed-field gel electrophoresis. Environmental cultures were negative. No breaches in infection control were identified. Endoscopic reprocessing exceeded manufacturer's recommended cleaning guidelines.

CONCLUSION

Recommended reprocessing guidelines are not sufficient.

Bacteremia and pneumonia in a tertiary PICU: an 11-year study

OBJECTIVES

To describe trends in aetiology and resistance patterns and patient outcomes of bacteraemia and pneumonia in a PICU over an 11-year period. We also describe interventions aimed at reducing multi-resistant infections and other serious bacterial infections in the PICU.

DESIGN AND SETTING

This cohort study involved data collected between January 2002 and December 2012 in the PICU of the Royal Children's Hospital in Melbourne, Australia. We documented all bacterial and fungal pathogens isolated from culture of blood or bronchial alveolar lavage fluid. Trends in aetiology and antibiotic resistance patterns were evaluated, as well as the case fatality rates of population-subgroups.

PATIENTS, MEASUREMENT AND MAIN RESULTS

Overall, 881 patients (8.9%) had 1,480 serious bacterial or fungal infections and 1.2% of the PICU population suffered a multidrug-resistant infection. Twenty-six percent of 597 total deaths in the PICU during that time period were associated with a serious bacterial infection of the blood or lungs. Children in PICU with a serious infection in blood or lungs had a case fatality rate of 17.5% (95% CI, 15.0-20.2), compared with children overall in the PICU with a case fatality rate of 6.0% (95% CI, 5.5-6.5). The case fatality rate among children with multidrug-resistant sepsis was 25.6% (95% CI, 18.1-34.4) and among children with a persistent or recurrent infection in blood or lungs was 43.1% (95% CI, 30.8-56.0). Cases of multidrug-resistant bacteremia and bronchial alveolar lavage-proven pneumonia increased from 2002 to 2010 and significantly decreased from 2011, coinciding with improvements in antibiotic stewardship and infection control.

CONCLUSIONS

Multiresistant bacterial sepsis and persistent or recurrent sepsis are major threats in pediatric intensive care and are associated with disproportionally high death rates. Our study describes a model for monitoring these serious infections and the effects of infection control interventions in the PICU.

Impact of Conversion from an Open Ward Design Paediatric Intensive Care Unit Environment to All Isolated Rooms Environment on Incidence of Bloodstream Infections and Antibiotic Resistance in Southern Israel (2000 to 2008)

We studied the epidemiology, microbiology, clinical aspects and outcome of bloodstream infections (BSI) in a tertiary paediatric intensive care unit. All BSI episodes were prospectively identified and analysed. The paediatric intensive care unit moved in 2006 from an open-plan unit to a new (all single room) unit. Three hundred and fifty-three BSI episodes occurred in 299 of 4162 patients. Overall, BSI incidence was 85 per 1000 hospitalised children. Fewer BSI episodes occurred during the last two years of the study (2007 to 2008), compared with 2000 to 2006 (70 of 1061 admissions, 6.5% versus 283 of 3101 admissions, 9.1%, respectively, P=0.01). There were 127 of 340 (37.4%) community-acquired and 213 of 340 (62.6%) nosocomial BSI episodes (31 of 1000 and 51 of 1000, respectively). Nosocomial BSI episodes decreased during 2007 to 2008 versus 2000 to 2006 (37.7% versus 55.8%, P=0.03). In 448 instances, pathogens were isolated, 231 (52%) Gram-positive and 188 (42%) Gram-negative. Coagulase-negative Staphylococci, S. pneumoniae and S. aureus (41.1%, 19.9% and 11.7%, respectively) were the most common Gram-positive and Enterobacteriaceae spp. the most frequent Gram-negative organisms (45.2%, of them Klebsiella spp. and E. coli 40% and 29.4%, respectively). A significant decrease was recorded during 2007 to 2008 in Enterobacteriaceae resistance to piperacillin, gentamicin and ciprofloxacin. Thirty of 299 (10%, 9 with S. pneumoniae-BSI) patients died. A significant decrease in BSI and nosocomial incidence and Enterobacteriaceae spp. antibiotic resistance was recorded following the conversion of the paediatric intensive care unit from an open ward to an all isolated rooms environment.

Adjunctive vancomycin powder in pediatric spine surgery is safe

STUDY DESIGN

Therapeutic level II cohort study.

OBJECTIVE

To evaluate the safety of adjunctive local application of vancomycin powder (VP) for infection prophylaxis in posterior instrumented thoracic and lumbar spine wounds in pediatric patients weighing more than 25 kg.

SUMMARY OF BACKGROUND DATA

Spine surgeons have largely turned to vancomycin prophylaxis in an attempt to decrease the incidence of late surgical site infection and acute surgical site infection from methicillin-resistant Staphylococcus aureus. In adult patients, the adjunctive local application of VP with an intravenous cephalosporin has been shown to decrease postsurgical wound infection rates significantly; however, the safety of VP as an adjunct in pediatric spine surgery has not been reported.

METHODS

We reviewed data collected under a systematic protocol specifically designed to monitor the safety profile of VP. We measured changes in creatinine and systemic vancomycin levels after intrawound application of 500 mg of unreconstituted VP during spine deformity correction surgery in patients weighing more than 25 kg (patients also received routine intravenous cephalosporin prophylaxis). Laboratory values were measured preoperatively and on postoperative days 1 and 4. Any adverse reactions and infections through available follow-up (2-8 mo) were recorded.

RESULTS

Eighty-seven consecutive pediatric patients with spinal deformity weighing more than 25 kg who received intraoperative VP during a 9-month period were identified. Sixty-three percent of the patients in this series had adolescent idiopathic scoliosis, 15% congenital scoliosis, 15% neuromuscular scoliosis, and 5% spondylolisthesis. The average change in creatinine levels between the preoperative and postoperative day 1 draw was -0.03 and between the preoperative and postoperative day 4 draw was -0.075. The postoperative systemic vancomycin levels remained undetectable. None of the patients experienced nephrotoxicity or red man syndrome. Three of the 87 patients developed a surgical site infection.

CONCLUSION

In this cohort there were no clinically significant changes in creatinine level or systemic vancomycin level caused by use of intraoperative VP.

LEVEL OF EVIDENCE

2.

Trends in antibiotic susceptibility and incidence of late-onset Klebsiella pneumoniae neonatal sepsis over a six-year period in a neonatal intensive care unit in Karachi, Pakistan

INTRODUCTION

The incidence, change in antibiotic susceptibility, and risk factors associated with mortality of late-onset Klebsiella pneumoniae sepsis during 2006-2011, in a neonatal intensive care unit (NICU) of a developing country, were analyzed.

METHODS

The medical records of neonates with a discharge diagnosis of sepsis due to late-onset K. pneumoniae were retrieved. Demographic features, gestational age, date and year of admission, antibiotic susceptibility of isolates, and discharge status were recorded. The late-onset K. pneumoniae incidence per 1000 NICU admissions and risk factors for mortality due to late-onset K. pneumoniae sepsis are reported.

RESULTS

During the period 2006-2011, 104 of 2768 neonates developed late-onset K. pneumoniae sepsis. The overall incidence of late-onset K. pneumoniae sepsis was 3.7% (37/1000 NICU admissions), with the highest annual incidence being 53/1000 in 2010. Most cases were males (n = 64; 62%) and most were premature and very low birth weight (n = 68; 65%). More than 80% of isolates were resistant to ampicillin + clavulanic acid, gentamicin, aztreonam, and cephalosporins. An increasing trend of resistance to amikacin, fluoroquinolones, piperacillin/tazobactam, and imipenem was observed. In 2011, three-quarters (72%; n=13) of late-onset K. pneumoniae were CR K. pneumoniae. Seventeen (16%) neonates died. Being male (p = 0.06, adjusted odds ratio (AOR) 9.2, 95% confidence interval (CI) 1.3-66.9), having an extremely low birth weight (p = 0.01, AOR 6.1, 95% CI 0.8-44.4), having severe thrombocytopenia (p = 0.07, AOR 3.9, 95% CI 1.2-13.0), and failure to achieve microbiological clearance (p < 0.001, AOR 19.6, 95% CI 4.0-98.0) were significantly associated with mortality due to late-onset K. pneumoniae sepsis.

CONCLUSION

There has been a rise in carbapenem-resistant strains of late-onset K. pneumoniae, associated with an increased mortality and limited antibacterial choices. Antimicrobial stewardship and rigorous infection control measures seem to be the only way to limit the spread of these strains.

Biofilm formation by clinical isolates and the implications in chronic infections

Background

Biofilm formation is a major virulence factor contributing to the chronicity of infections. To date few studies have evaluated biofilm formation in infecting isolates of patients including both Gram-positive and Gram-negative multidrug-resistant (MDR) species in the context of numerous types of infectious syndromes. Herein, we investigated the biofilm forming capacity in a large collection of single patient infecting isolates and compared the relationship between biofilm formation to various strain characteristics.

Methods

The biofilm-forming capacity of 205 randomly sampled clinical isolates from patients, collected from various anatomical sites, admitted for treatment at Brooke Army Medical Center (BAMC) from 2004–2011, including methicillin-resistant/methicillin susceptible Staphylococcus aureus (MRSA/MSSA) (n=23), Acinetobacter baumannii (n=53), Pseudomonas aeruginosa (n=36), Klebsiella pneumoniae (n=54), and Escherichia coli (n=39), were evaluated for biofilm formation using the high-throughput microtiter plate assay and scanning electron microscopy (SEM). Relationships between biofilm formation to clonal type, site of isolate collection, and MDR phenotype were evaluated. Furthermore, in patients with relapsing infections, serial strains were assessed for their ability to form biofilms in vitro.

Results

Of the 205 clinical isolates tested, 126 strains (61.4%) were observed to form biofilms in vitro at levels greater than or equal to the Staphylococcus epidermidis, positive biofilm producing strain, with P. aeruginosa and S. aureus having the greatest number of biofilm producing strains. Biofilm formation was significantly associated with specific clonal types, the site of isolate collection, and strains positive for biofilm formation were more frequently observed to be MDR. In patients with relapsing infections, the majority of serial isolates recovered from these individuals were observed to be strong biofilm producers in vitro.

Conclusions

This study is the first to evaluate biofilm formation in a large collection of infecting clinical isolates representing diverse types of infections. Our results demonstrate: (1) biofilm formation is a heterogeneous property amongst clinical strains which is associated with certain clonal types, (2) biofilm forming strains are more frequently isolated from non-fluid tissues, in particular bone and soft tissues, (3) MDR pathogens are more often biofilm formers, and (4) strains from patients with persistent infections are positive for biofilm formation.

Investigation and control of an outbreak of imipenem-resistant Acinetobacter baumannii Infection in a Pediatric Intensive Care Unit

BACKGROUND

This study investigated the clinical details and epidemiology of the imipenem-resistant Acinetobacter baumannii (IRAB) outbreak that occurred at a pediatric intensive care unit (PICU), and describes successful outcome of the implemented infection control measures.

METHODS

With the recognition of 3 clustered cases with IRAB bacteremia at the PICU of Seoul National University Children's Hospital, Korea, from August to September 2010, the following outbreak control strategies were implemented: reinforcement of hand hygiene and contact precautions, investigation of environmental contamination, disinfection of the contaminated environment and medical equipment, active surveillance culture upon PICU admission and isolation of IRAB-positive patients. The clinical and microbiological data were reviewed for A. baumannii positive cases in the PICU from April 2001 to June 2011. Multilocus sequence typing was also performed.

RESULTS

Twenty IRAB-positive cases (bacteremia in 10, pneumonia in 3 and colonizers in 7) were detected from January 2010 to February 2011. Thirteen IRAB-infected patients were all placed on a mechanical ventilator, had central venous catheters, received broad-spectrum antimicrobial treatment and had underlying diseases. Eleven (85%) IRAB-infected patients died probably due to IRAB infection. IRAB grew in 4 samples obtained from sinks and water taps from 38 environmental samples. Multilocus sequence typing analysis revealed 2 sequence types: ST138 (n=16) and its single-locus variant ST92 (n=4). Eleven weeks after the initiation of active surveillance, no further IRAB isolates were identified.

CONCLUSIONS

This study identifies the environmental source of an IRAB outbreak in a PICU and describes successful control of the outbreak with a multicomponent intervention program.

Cathelicidin-related antimicrobial peptide is required for effective lung mucosal immunity in Gram-negative bacterial pneumonia

Cathelicidins are a family of endogenous antimicrobial peptides that exert diverse immune functions, including both direct bacterial killing and immunomodulatory effects. In this study, we examined the contribution of the murine cathelicidin, cathelicidin-related antimicrobial peptide (CRAMP), to innate mucosal immunity in a mouse model of Gram-negative pneumonia. CRAMP expression is induced in the lung in response to infection with Klebsiella pneumoniae. Mice deficient in the gene encoding CRAMP (Cnlp(-/-)) demonstrate impaired lung bacterial clearance, increased bacterial dissemination, and reduced survival in response to intratracheal K. pneumoniae administration. Neutrophil influx into the alveolar space during K. pneumoniae infection was delayed early but increased by 48 h in CRAMP-deficient mice, which was associated with enhanced expression of inflammatory cytokines and increased lung injury. Bone marrow chimera experiments indicated that CRAMP derived from bone marrow cells rather than structural cells was responsible for antimicrobial effects in the lung. Additionally, CRAMP exerted bactericidal activity against K. pneumoniae in vitro. Similar defects in lung bacterial clearance and delayed early neutrophil influx were observed in CRAMP-deficient mice infected with Pseudomonas aeruginosa, although this did not result in increased bacterial dissemination, increased lung injury, or changes in lethality. Taken together, our findings demonstrate that CRAMP is an important contributor to effective host mucosal immunity in the lung in response to Gram-negative bacterial pneumonia.

Decreased aztreonam susceptibility among Pseudomonas aeruginosa isolates from hospital effluent treatment system and clinical samples

The aim of this study was to evaluate the antimicrobial resistance patterns of Pseudomonas aeruginosa isolates from hospital wastewater treatment system (HWTS) and clinical specimens in a hospital of Rio de Janeiro city, Brazil. Forty-three isolates obtained from four of the five steps of the HWTS (n = 27) and clinical samples (n = 16) from patients were analyzed regarding their susceptibility profiles to 12 antibiotics. Clinical isolates exhibited higher resistance profiles to antibiotics than wastewater isolates. However, out of 27 isolates from sewage, 62.9% showed decreased susceptibility to aztreonam while 50% of clinical isolates were resistant to this antibiotic. Isolates were not detected at the chlorination stage but they were obtained from the following stage of the treatment revealing the capacity of regrowth after chlorinated sewage effluent. To our knowledge, this is the first study reporting decreased aztreonam susceptibility among P. aeruginosa isolates from a hospital wastewater treatment system. Further investigations are being conducted by our laboratory including a larger sampling program in order to obtain more data.

Vancomycin-resistant enterococcus outbreak in a pediatric intensive care unit: report of successful interventions for control and prevention

The objective of this study is to retrospectively report the results of interventions for controlling a vancomycin-resistant enterococcus (VRE) outbreak in a tertiary-care pediatric intensive care unit (PICU) of a University Hospital. After identification of the outbreak, interventions were made at the following levels: patient care, microbiological surveillance, and medical and nursing staff training. Data were collected from computer-based databases and from the electronic prescription system. Vancomycin use progressively increased after March 2008, peaking in August 2009. Five cases of VRE infection were identified, with 3 deaths. After the interventions, we noted a significant reduction in vancomycin prescription and use (75% reduction), and the last case of VRE infection was identified 4 months later. The survivors remained colonized until hospital discharge. After interventions there was a transient increase in PICU length-of-stay and mortality. Since then, the use of vancomycin has remained relatively constant and strict, no other cases of VRE infection or colonization have been identified and length-of-stay and mortality returned to baseline. In conclusion, we showed that a bundle intervention aiming at a strict control of vancomycin use and full compliance with the Hospital Infection Control Practices Advisory Committee guidelines, along with contact precautions and hand-hygiene promotion, can be effective in reducing vancomycin use and the emergence and spread of vancomycin-resistant bacteria in a tertiary-care PICU.