Antibiotics in the Intensive Care Unit: Focus on Agents for Resistant Pathogens

Analysis of the use of antibiotics profile and factors of surgical site infections study on digestive and oncology surgeries

OBJECTIVES

The incision method operation with a high risk of infection in a clean and clean-contaminated operation requires the use of prophylactic antibiotics to minimize the risk of infection. This study was designed to analyze the effectiveness of prophylactic antibiotics in patients with digestive and oncology surgeries.

METHODS

The statistical method used was chi-square to determine the risk factors for infection at surgical site infections (SSI) in patients with digestive and oncology surgeries. This study had received ethical approval from the Ethics Committee of Dr. H. Slamet Martodirdjo Hospital, Pamekasan.

RESULTS

There were 67 patients consisted of 48 digestive surgeries (71.6%) and 19 oncology surgeries (28.4%). The criteria of observation on day 30 showed that as 1 (1.5%) SSI patient experienced purulence, inflammation, and erythema around the surgical wound so an analysis of p>0.05 was carried out so that there was no association with the incidence of SSI during hospitalization, but other factors originating from the patient, such as a lack of personal hygiene at home and lack of nutritious food intake was measured in temperature, pulse, respiration, and white blood cells examination before surgery and 24 h after surgery, all within normal ranges. The qualitative analysis of prophylactic antibiotics using the Gyssen method showed that 31 (46.3%) rationales needed an improvement process.

CONCLUSIONS

The widely used prophylactic antibiotics, namely cefazolin and cefuroxime are recommended antibiotics used in incision surgery and rationale used.

Infection with multidrug-resistant gram-negative bacteria in a pediatric oncology intensive care unit: risk factors and outcomes

OBJECTIVE

This study aimed at evaluating the predictors and outcomes associated with multidrug-resistant gram-negative bacterial (MDR-GNB) infections in an oncology pediatric intensive care unit (PICU).

METHODS

Data were collected relating to all episodes of GNB infection that occurred in a PICU between January of 2009 and December of 2012. GNB infections were divided into two groups for comparison: (1) infections attributed to MDR-GNB and (2) infections attributed to non-MDR-GNB. Variables of interest included age, gender, presence of solid tumor or hematologic disease, cancer status, central venous catheter use, previous Pseudomonas aeruginosa infection, healthcare-associated infection, neutropenia in the preceding 7 days, duration of neutropenia, length of hospital stay before ICU admission, length of ICU stay, and the use of any of the following in the previous 30 days: antimicrobial agents, corticosteroids, chemotherapy, or radiation therapy. Other variables included initial appropriate antimicrobial treatment, definitive inadequate antimicrobial treatment, duration of appropriate antibiotic use, time to initiate adequate antibiotic therapy, and the 7- and 30-day mortality.

RESULTS

Multivariate logistic regression analyses showed significant relationships between MDR-GNB and hematologic diseases (odds ratio [OR] 5.262; 95% confidence interval [95% CI] 1.282-21.594; p=0.021) and healthcare-associated infection (OR 18.360; 95% CI 1.778-189.560; p=0.015). There were significant differences between MDR-GNB and non-MDR-GNB patients for the following variables: inadequate initial empirical antibiotic therapy, time to initiate adequate antibiotic treatment, and inappropriate antibiotic therapy.

CONCLUSIONS

Hematologic malignancy and healthcare-associated infection were significantly associated with MDR-GNB infection in this sample of pediatric oncology patients.

Green tea catechins quench the fluorescence of bacteria-conjugated Alexa fluor dyes

Accumulating evidence suggests that Green tea polyphenolic catechins, especially the (-)-epigallocatechin gallate (EGCG), can be cross-linked to many proteins, and confer a wide range of anti-bacterial activities possibly by damaging microbial cytoplasmic lipids and proteins. At the doses that conferred protection against lethal polymicrobial infection (induced by cecal ligation and puncture), EGCG significantly reduced bacterial loads particularly in the liver and lung. To elucidate its bactericidal mechanisms, we determined whether EGCG affected the fluorescence intensities of bacteria-conjugated Alexa Fluor 488 or 594 dyes. When mixed with unconjugated Alexa Fluor 488 or 594 dyes, EGCG or analogs did not affect the fluorescence intensity of these dyes. In a sharp contrast, EGCG and some analogs (e.g., Catechin Gallate, CG), markedly reduced the fluorescence intensity of Gram-positive Staphylococcus aureus-conjugated Alexa 594 and Gram-negative Escherichia coli-conjugated Alexa 488. Interestingly, co-treatment with ethanol impaired the EGCG-mediated fluorescence quenching of the G(+) S. aureus, but not of the G(-) E. coli-conjugated Alexa Flour dyes. In light of the notion that Alexa Fluor dyes can be quenched by aromatic amino acids, it is plausible that EGCG exerts antimicrobial activities possibly by altering microbial protein conformations and functions. This possibility can now be explored by screening other fluorescence-quenching agents for possible antimicrobial activities.

[Evolution of susceptibility to antibiotics of Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Acinetobacter baumanii, in a University Hospital Center of Beirut between 2005 and 2009]

INTRODUCTION

Until recently, multiresistant bacteria were only limited to hospitals. However, they are now responsible for community acquired infections, affecting people who have had no contact with the hospital environment. Several mechanisms are associated with these resistances. The production of betalactamases is however the predominant mechanism and especially the production of extended spectrum beta-lactamases or ESBL by strains of Escherichia coli and Klebsiella pneumoniae, which mediate resistance to third generation cephalosporins and aztreonam (AZT). The association of multiple mechanisms of resistance (efflux pumps, impermeability and enzymatic inactivation) generates multi resistant bacteria such as Pseudomonas aeruginosa MDR and Klebsiella pneumoniae MDR.

AIM OF THE STUDY

The aim of the study was to analyze retrospectively the susceptibility to antibiotics of strains of E. coli, K. pneumoniae, P. aeruginosa and A. baumanii isolated from hospitalized and outpatients in a university hospital center of Beirut over a period of five years from 2005 to 2009.

MATERIALS AND METHODS

Bacterial strains were classified according to their origin (inpatients versus outpatients), their ability to produce or not ESBLs for E. coli and K. pneumonia and if they were MDR for P. aeruginosa and A. baumanii. Antibiotics susceptibilities were retrieved from the informatics database of the hospital. Comparison of susceptibility percentages was done using a unilateral z-test on a computer program.

RESULTS

In 2009, 2541 strains of E. coli were isolated, 773 of which or 30.4 % were ESBL producers while 2031 strains were isolated in 2005, of which 361 or 17.8 % were ESBL producers (p<0.001). We noticed a decrease in hospital strains susceptibility to ceftazidime (CAZ) and AZT, between 2005 and 2009 (p<0.001), and a decrease in community strains susceptibility to triméthoprime/sulfaméthoxazole (SXT) between 2005 and 2009 (p=0.03). We noted however a significant decrease of ESBL producing strains between 2007 and 2009: 33.4 % versus 30.4 % (p=0.03). Among 560 strains of K. pneumoniae isolated in 2009, 178 strains or 31.8 % were ESBL producers in comparison to 23.7 % of the strains isolated in 2005 (p=0.03). We also noticed a decrease in hospital strains susceptibility to piperacilline-tazobactam (TZP), cefotaxime (CTX) and AZT (p<0.001 p=0.03 and p=0.03 respectively) between 2006 and 2009, and a significant increase in ESBL producing strains between 2008 et 2009 (p=0.0001). 26.5 % of P. aeruginosa strains isolated in 2009 were MDR bacteria with no significant change as compared to 26.6 % in 2005 (p=0.5). However, the percentage of MDR strains slightly decreased between 2008 and 2009 (p=0.047). The susceptibility of MDR strains to CAZ and imipenem (IMP) decreased between 2005 and 2009 (p<0.001 and P=0.003 respectively). As for A. baumanii, 77.7 % of strains were MDR in 2009 in comparison to 73.4 % in 2005 (p=0.24) with a dramatic decrease of MDR strains susceptibility to IMP from 92.3 % in 2006 to 30 % in 2009 (p<0.001).

CONCLUSION

Despite restrictions on antibiotics prescriptions and isolation of patients harboring MDR bacteria or bacteria producing ESBL, there has not been satisfactory reduction of multi resistant bacteria and efforts should be made to reduce these bugs from the hospital flora.

Clinical characteristics of nosocomial infections in neonatal intensive care unit in eastern China

A retrospective cohort study on nosocomial infections (NI) in the neonatal intensive care unit (NICU) was performed in the Children's Hospital of Zhejiang University, Hangzhou district, China. The most common infection site was pneumonia and bloodstream infection. Low admission age, long NICU stay, and mechanical ventilation were significant risk factors for NI. Klebsiella pneumoniae was the most common pathogen, followed by Acinetobacter baumannii, Staphylococcus epidermidi, Pseudomonas aeruginosa, Enterobacter cloacae, and Stenotrophomonas maltophilia. Antibiotic resistance of the isolated bacterium was high. In conclusion, this study described the clinical characteristics of NI in a Chinese NICU, which might contribute to implementation of more effective therapeutic and preventive strategies.

Antimicrobial Stewardship in the Intensive Care Unit: A Focus on Potential Pitfalls

Patients in the intensive care unit (ICU) have many risk factors for resistant pathogens such as prolonged length of stay, frequent and broad-spectrum antimicrobial therapy, presence of foreign materials, and proximity with other patients. However, of the risk factors associated with acquisition of resistant pathogens, inappropriate use of antimicrobial agents has been the most implicated. Thus, many health care institutions have adopted antimicrobial stewardship programs (ASPs) as a mechanism to ensure more appropriate antimicrobial use. ASPs can have a significant impact in the ICU, leading to improved antimicrobial use and resistance patterns and decreased infection rates and costs, due to the inherent nature of infections encountered and high and often inappropriate antibiotic utilization in this setting. However, certain challenges exist for ASPs in the ICU including issues with infrastructure and personnel, information technology, the core ASP strategy, patient-specific factors, conversion of intravenous to oral therapy, and dose optimization. The combination of comprehensive infection control (IC) and effective antimicrobial stewardship can prevent the emergence of resistance among microorganisms and may decrease the negative consequences associated with antimicrobial misuse.

Doripenem in hospital infections: a focus on nosocomial pneumonia, complicated intra-abdominal infections, and complicated urinary tract infections

Doripenem is the latest carbapenem on the market to date. Although not an antibiotic in a new class, it offers a glimmer of hope in combating serious infections secondary to multidrug-resistant Gram-negative bacteria when we have not seen a new class of antibacterial, particularly for Gram-negative bacteria, for more than 10 years. In vitro, doripenem exhibits a broad spectrum of activity against Gram-positive and Gram-negative bacteria, including extended-spectrum β-lactamase (ESBL) and Amp-C β-lactamase producing Enterobacteriaceae and anaerobes. Doripenem also exhibits better in vitro activity against Pseudomonas aeruginosa compared to other anti-pseudomonal carbapenems. It combines the desirable activities of both imipenem and meropenem. It has similar activity to imipenem against Gram-positive pathogens and has the antimicrobial spectrum of meropenem against Gram-negative organisms. Several randomized clinical trials have demonstrated that doripenem is non-inferior to meropenem, imipenem, piperacillin/tazobactam, or levofloxacin in its efficacy and safety profile in treating a wide range of serious bacterial infections including intra-abdominal infection, complicated urinary tract infection, and nosocomial pneumonia. Due to its wide spectrum of activity and good safety profile it is susceptible to misuse leading to increasing rates of resistance. Judicious use should be considered when using doripenem as a first-line agent or drug of choice for serious infections. Doripenem is a well-tolerated drug with common adverse effects including headache, nausea and diarrhea. Caution should be used in patients with hypersensitivity to carbapenems and adverse reactions to β-lactam agents. Dosage adjustment is needed for patients with renal impairment. Doripenem has demonstrated economic and clinical benefits. It has been shown to reduce hospital length of stay and duration of mechanical ventilation for intensive care unit (ICU) patients. Therefore, doripenem is a welcome addition to our limited armamentarium of antibiotics available to treat serious bacterial infections in hospitalized patients.