Health-care-associated infection: morbidity, mortality and costs

ADMET profiling and molecular docking of potential antimicrobial peptides previously isolated from African catfish, Clarias gariepinus

Amidst rising cases of antimicrobial resistance, antimicrobial peptides (AMPs) are regarded as a promising alternative to traditional antibiotics. Even so, poor pharmacokinetic profiles of certain AMPs impede their utility necessitating, a careful assessment of potential AMPs' absorption, distribution, metabolism, excretion, and toxicity (ADMET) properties during novel lead exploration. Accordingly, the present study utilized ADMET scores to profile seven previously isolated African catfish antimicrobial peptides (ACAPs). After profiling, the peptides were docked against approved bacterial protein targets to gain insight into their possible mode of action. Promising ACAPs were then chemically synthesized, and their antibacterial activity was validated in vitro utilizing the broth dilution method. All seven examined antimicrobial peptides passed the ADMET screening, with two (ACAP-IV and ACAP-V) exhibiting the best ADMET profile scores. The ACAP-V had a higher average binding energy (-8.47 kcal/mol) and average global energy (-70.78 kcal/mol) compared to ACAP-IV (-7.60 kcal/mol and -57.53 kcal/mol), with the potential to penetrate and disrupt bacterial cell membrane (PDB Id: 2w6d). Conversely, ACAP-IV peptide had higher antibacterial activity against E. coli and S. aureus (Minimum Inhibitory Concentration, 520.7 ± 104.3 μg/ml and 1666.7 ± 416.7 μg/ml, respectively) compared to ACAP-V. Collectively, the two antimicrobial peptides (ACAP-IV and ACAP-V) are potential novel leads for the food, cosmetic and pharmaceutical industries. Future research is recommended to optimize the expression of such peptides in biological systems for extended evaluation.

Endoscopic dacryocystorhinostomy in acute dacryocystitis: a multicenter case series

OBJECTIVE

To present our experience of early endonasal DCR (endoDCR) in the treatment of acute dacryocystitis (AD). Methods. International multicenter non-comparative retrospective study.

RESULTS

Eighteen patients were identified. All were treated with antibiotics prior to surgery with a median of time from referral to endoDCR surgeon to surgery of 3 days (range 1-7). Surgery was performed using mechanical powered endoDCR (MENDCR) in 15/18 (83.3%) cases; mitomycin C was used in 5/18 (27.8%) and all cases underwent bicanalicular intubation. An increase in perioperative bleeding was noted in 5/18 (27.8%), causing interference in surgical technique in one (5.6%). Resolution of AD was seen in all cases, with no recurrences. 17/18 (94.4%) cases were free of epiphora at median follow-up of 12 months (range 2-36), with nasal endoscopy revealing free flow of fluorescein through the ostium in 17/18 (94.4%) of cases. The median total length of stay was 1 night (range 0-3).

CONCLUSIONS

EndoDCR surgery performed early in AD led to rapid resolution of the condition in all cases and was associated with subsequent anatomical and functional success in 94.4% of cases. Early endoDCR surgery in the context of AD and the potential associated health economic benefits are worth further consideration and study.

Point-of-use water filtration reduces endemic Pseudomonas aeruginosa infections on a surgical intensive care unit

BACKGROUND

Endemic infections because of Pseudomonas aeruginosa were observed on a surgical intensive care unit (ICU) for a period of >24 months. Tap water probing revealed persistent colonization of all ICU water taps with a single P aeruginosa clonotype.

METHODS

Water outlets of the ICU were equipped with disposable point-of-use water filters, changed in weekly and, later, 2-week intervals. To delineate the effect of the filters, 4 study approaches were followed: (1) a descriptive analysis of the incidence of P aeruginosa colonizations and infections, (2) microbiologic examinations of tap water before and after installation of the filters, (3) a comparative cohort analysis of representative patient samples from the prefilter and postfilter time periods, and (4) an analysis of general ward variables for the 2 periods.

RESULTS

(1) The mean monthly rate (+/-SD) of P aeruginosa infection/colonization episodes was 3.9 +/- 2.4 in the prefilter and 0.8 +/- 0.8 in the postfilter period. P aeruginosa colonizations were reduced by 85% (P < .0001) and invasive infections by 56% (P < .0003) in the postfilter period. (2) Microbiologic examinations of tap water revealed growth of P aeruginosa in 113 of 117 (97%) samples collected during the prefilter period, compared with 0 of 52 samples taken from filter-equipped taps. (3) In the comparative cohort analysis, a number of patient-related variables were significantly associated with P aeruginosa colonization/infection. Considering these variables in a multivariate analysis, belonging to the postfilter cohort was the factor most strongly associated with a reduced risk of P aeruginosa positivity (relative risk, 0.04; P = .0002). (4) General ward variables such as bed occupancy, personnel-to-patient ratio, or microbiologic culturing density did not differ significantly between the 2 periods.

CONCLUSION

Taking into account various patient-related and general ward variables, point-of-use water filtration was associated with a significant reduction of chronically endemic P aeruginosa colonizations/infections on a surgical ICU.

Prospective evaluation of hospital isolation room capacity

Risk assessment is used to determine the need for isolation in single rooms. Limited availability of isolation rooms and/or operational needs may compromise this process. This article reports the results of a 12-month prospective observational study of every infection control request for isolation in a 1100-bed teaching hospital. In addition, four point-prevalence surveys of the usage of single rooms were carried out. Data were collected on the incidence of new clinical meticillin-resistant Staphylococcus aureus (MRSA) isolates per ward and these were correlated with rates of isolation failures for MRSA cases. There were 845 requirements for patient isolation, of which 185 (22%) could not be met (isolation failures). Three-quarters of the requirements for isolation were due to MRSA or Clostridium difficile. The proportion of isolation failures was consistent for most organisms and conditions but varied markedly between clinical specialities (0-57%). Reasons for failure to isolate included no single rooms available, all single/isolation rooms occupied (for both isolation and non-infection-control reasons), limitations on the use of single rooms in mixed-sex wards and patient-specific reasons. Only a minority of the available single rooms were occupied for infection control reasons (12-19%). There was a statistically significant correlation between isolation failures and MRSA incidence (Spearman's rho 0.596, P<0.001). In only one case where a ward had >or=30% of its beds provided in single rooms was there an instance of failure to isolate. In conclusion, insufficient capacity to isolate patients with potentially transmissible pathogens is common and may compromise infection control requirements. Either isolation capacity must be increased or evidence-based risk assessment must be applied to situations where demand for isolation exceeds availability. Further information is needed on the consequences of isolation failure.

Influence of antibiotic therapy on mortality of critical surgical illness caused or complicated by infection

BACKGROUND

Conceptually, appropriateness of antibiotic therapy includes choice of agent relative to susceptibility of pathogens as well as dosing, timing of onset, and duration of therapy, but is most commonly considered in terms of choice of antibiotic. It has been suggested that inappropriate antibiotic selection can result in increased mortality. This study was performed to elucidate the role of scheduled, rotating antibiotic therapy in defining mortality among febrile, infected surgical ICU patients.

METHODS

Prospective inception-cohort study of 356 patients during their initial episode of fever (temperature > 38.2 degrees C), caused by infection diagnosed by positive cultures or direct inspection (some cases of peritonitis). Collected data included age, gender, admission APACHE III score, peak temperature, microbial isolates and susceptibility, source of infection, multiple organ dysfunction score, mortality, and several time intervals (time that cultures were collected, time from collection to antibiotic prescription, time from collection to antibiotic administration, duration of therapy).

RESULTS

The mean age was 63 +/- 1 years, the mean APACHE III score was 74 +/- 2 points, the mean multiple organ dysfunction score was 8 +/- 1 points, and overall mortality was 31%. Neither the source of infection nor the specific isolate influenced mortality. Antibiotic therapy was appropriate (covered the isolates) in 94% of cases, and did not influence mortality. Duration of therapy was identical between groups (5.1 +/- 0.3 vs. 5.4 +/- 0.3 days, p = 0.61). By logistic regression (dependent variable = mortality), APACHE III score OR 1.025, 95% C.I. 1.021-1.04) and delayed antibiotic administration (30-min intervals, OR 1.021, 95% C.I. 1.003-1.038) were independent predictors of mortality.

CONCLUSIONS

The use of scheduled monthly antibiotic cycling in the surgical ICU is associated with a high rate of "appropriate" antibiotic therapy, and appears to maintain or improve resistance patterns. Because antibiotic therapy was mostly appropriate for isolates, initial inappropriate therapy could not be identified as a risk factor for mortality. However, in the setting of appropriate antibiotic choice, the prompt initial administration of antibiotics appears to be crucial for survival, but neither site of infection nor specific pathogen are influential.

Hospital water point-of-use filtration: a complementary strategy to reduce the risk of nosocomial infection

Cholera, hepatitis and typhoid are well-recognized water-borne illnesses that take the lives of many every year in areas of uncontrollable flood, but far less attention is afforded to the allegedly safe potable water in affluent nations and the presumed healthful quality of water in communities and hospitals. Recent literature, however, points to increasing awareness of serious clinical sequelae particularly experienced by immunocompromised patients at high risk for disease and death from exposure to water-borne microbes in hospitals. This review reflects the literature indicting hospital water as an important source for nosocomial infections, examines patient populations at greatest risk, uncovers examples of failures in remedial water treatment methods and the reasons for them, and introduces point-of-use water filtration as a practical alternative or complementary component of an infection control strategy that may reduce the risk of nosocomial infections.