Prevalence Of Antibiotic-resistant Organisms Research Articles

Epidemiology and risk factors for pyogenic liver abscess in the Calgary Health Zone revisited: a population-based study

BackgroundPyogenic liver abscess (PLA), although uncommon in North America, is associated with significant morbidity and mortality. We sought to re-examine the epidemiology, risk factors, and outcomes of PLA in a large, diverse Canadian health zone.MethodsAll Calgary Health Zone (CHZ) residents aged ≥20 with PLA between 2015 and 2017 were identified. Incidence and mortality rates were calculated using census data. Risk factors for PLA were identified using a multivariate analysis. Data was compared to 1999–2003 data, also collected in the CHZ.ResultsThere were 136 patients diagnosed with PLA between 2015 and 2017. Incidence rate during this period increased significantly relative to 1999–2003 (3.7 vs 2.3 cases/100,000 population, p < 0.01), however, mortality rates remained similar. The microbiological composition of PLA did not change over this 15-year time period but the number of antimicrobial resistant isolates did increase (8% vs 1%, p = 0.04). The greatest risk factors for PLA relative to general populations included current malignancy, liver-transplant, end-stage renal disease, and cirrhosis. Thirty-day mortality was 7.4% and independent risk factors included polymicrobial bacteremia, absence of abscess drainage, congestive-heart failure, a history of liver disease, and admission bilirubin.ConclusionsPyogenic liver abscess is a health concern with rising incidence rate. The increasing prevalence of comorbidities in our population and factors that are associated with risk of PLA suggests this will continue to be an emerging diagnosis of concern. Increasing prevalence of antibiotic resistant organisms compounding unclear optimal treatment regimens is an issue that requires urgent study.

Prevalence of antibiotic-resistant organisms among hospitalized patients at a tertiary care center in Lebanon, 2010–2018

BackgroundInfections due to antibiotic resistant organisms (ARO) among hospitalized patients are associated with increased morbidity, mortality, and healthcare costs. Longitudinal data about antimicrobial resistance are scarce in Lebanon and the region. The objective of this study is to describe the temporal trends of resistance of selected pathogens among hospitalized patients at a tertiary care center in Lebanon. MethodsWe conducted a retrospective review of surveillance data from 2010 until 2018. Six target organisms isolated from hospitalized patients were included: carbapenem-resistant Escherichia coli (CREC), carbapenem-resistant Klebsiella spp. (CRKP), multi-drug resistant Pseudomonas aeruginosa (MDRPA), carbapenem-resistant Acinetobacter baumannii (CRAB), methicillin-resistant Staphylococcus aureus (MRSA), and vancomycin-resistant Enterococcus spp. (VRE). Correlation analysis was performed to evaluate for temporal trends. ResultsA total of 15,901 isolates were examined, most of which were obtained from urinary specimens. Among Gram-negative organisms, the highest resistance was found among CRAB (81.7%), followed by CRKP (6.5%) and CREC (3.3%). MDRPA overall prevalence was 0.8%. Among Gram-positive organisms, the prevalence of MRSA and VRE was 26.2% and 2.6%, respectively. CREC, MRSA, and VRE showed statistically significant increasing temporal trends, while CRAB decreased significantly from 2013 to 2018. ConclusionThese data are helpful in characterizing the epidemiology of antimicrobial resistance in Lebanon and show that controlling emerging resistance is achievable with concerted infection control and antimicrobial stewardship efforts. Caution should be exercised to contain early on the spread of CREC and of resistant Gram-positive pathogens.

Antimicrobial Resistant Organisms in Sepsis at a Referral Hospital in Malawi

Background: There are scarce data describing the etiology and clinical sequelae of sepsis in LMICs. In particular, the prevalence of antibiotic resistant organisms is not well characterized. This study describes the prevalence of sepsis amongst critically ill patients, antibiotic stewardship, and the prevalence of antimicrobial resistant pathogens at a referral hospital in Malawi. Methods: We conducted an observational prospective cohort study of adults admitted to the ICU or HDU of a referral hospital in Malawi from January 29 to March 15, 2018. We stratified the cohort based on the prevalence of sepsis, defined by a qSOFA score ≥2 plus suspected infection. We measured clinical characteristics, blood and urine cultures, and antimicrobial sensitivities from positive cultures. Findings: During the study period, 103 patients were admitted and 76 patients were analyzed. The cohort was 47% male, and the median age 30 years (IQR, 23-40). Most participants (74%) had initiated antibiotics prior to study recruitment, commensurate with a suspicion of infection in 68% of patients. Four blood cultures (5%) were positive, two from patients with sepsis. All blood bacterial isolates were multi-drug resistant. Of seven patients with urinary tract infection, three had sepsis secondary to multi-drug resistant bacteria. Hospital mortality for patients with sepsis was 73% versus 22% for non-septic patients (p=0·001). Interpretation: Mortality associated with sepsis in the ICU and HDUs at this Malawi hospital is high. Bacteremia was infrequently detected, but isolated pathogens were multi-drug resistant. These data highlight the need for laboratory infrastructure to guide antibiotic stewardship in Malawi. Funding Statement: This study was supported in part by the NIH Fogarty International Center Postdoctoral Research Fellowship to Dr. Prin and by the Friedman Award from Columbia University College of Physicians and Surgeons to Dr. Onofrey. Declaration of Interests: The authors declare no conflicts of interest. Ethics Approval Statement: The study protocol was approved by the National Health Sciences Research Council of Malawi and the Institutional Review Boards of both American universities with which the study was affiliated, and the requirement for written informed consent was waived by all ethics oversight bodies.

Prevalence of antibiotic-resistant organisms in Canadian Hospitals. Comparison of point-prevalence survey results from 2010, 2012, and 2016.

Point-prevalence surveys for infection or colonization with methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus (VRE), extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae, carbapenem-resistant Enterobacteriaceae (CREs), and for Clostridium difficile infection (CDI) were conducted in Canadian hospitals in 2010 and 2012 to better understanding changes in the epidemiology of antimicrobial-resistant organisms (AROs), which is crucial for public health and care management. A third survey of the same AROs in adult inpatients in Canadian hospitals with ≥50 beds was performed in February 2016. Data on participating hospitals and patient cases were obtained using standard criteria and case definitions. Associations between ARO prevalence and institutional characteristics were assessed using logistic regression models. In total, 160 hospitals from 9 of the 10 provinces with 35,018 adult inpatients participated in the survey. Median prevalence per 100 inpatients was 4.1 for MRSA, 0.8 for VRE, 1.1 for CDI, 0.8 for ESBLs, and 0 for CREs. No significant change occurred compared to 2012. CREs were reported from 24 hospitals (15%) in 2016 compared to 10 hospitals (7%) in 2012. Routine universal or targeted admission screening for VRE decreased from 94% in 2010 to 74% in 2016. Targeted screening for MRSA on admission was associated with a lower prevalence of MRSA infection. Large hospitals (&gt;500 beds) had higher prevalences of CDI. This survey provides national prevalence rates for AROs in Canadian hospitals. Changes in infection control and prevention policies might lead to changes in the epidemiology of AROs and our capacity to detect them.

What Is the Benefit of Instillation Therapy?

Over the past decade, the concept of proper wound bed preparation as a means to improve wound healing has gained increasing attention. The principles of wound bed preparation include proper wound debridement, managing wound exudates, and managing bioburden. Proper wound bed preparation creates an optimal wound healing environment. The presence of necrotic tissue or eschar is known to impede healing. Likewise, the presence of abnormally high levels of bacteria may also impede healing. These impediments to wound healing may in part be removed by practices such as wound irrigation. Cleansing the wound by using an irrigant to remove loosely attached bacteria and cellular or other debris may decrease wound complications, thereby allowing the wound to heal in a timely fashion. Typically, wound irrigation is conducted at pressures less than 103.4 kPa using an irrigant that does not cause trauma to the surrounding tissue. Typical devices used to deliver irrigants to wounds include spray bottles, syringes, squeeze bottles, and pulsatile lavage devices. We consider all these types of approaches to fall under the category of instillation therapy. The clinical application of instillation therapy for treating wounds was first described by Fleischmann et al in 1998. Since then, several clinical articles have described various applications of instillation therapy, most of which address the treatment of wound infections. For example, Gabriel et al reported the use of instillation therapy for treating soft tissue infection. They showed that instilling silver nitrate was effective at reducing bioburden, time to wound closure, and time to hospital discharge. Others have followed with similar clinical results. Schintler et al and Timmers et al showed that instilling polyhexanide solution was effective at treating soft tissue necrotizing fasciitis and osteomyelitis. Even though the utility of wound irrigation for infected wounds is an accepted practice, cross-contamination from the splatter, which may be caused during the instillation process, is a safety concern to both the patient and the clinician. In a recent study, Angobaldo et al showed that bacteria from pulsatile lavage–treated wounds could be captured 3 feet away from the wound. The spread of organisms and especially resistant organisms in the hospital environment is a growing concern. Studies have demonstrated that methicillinresistant Staphylococcus aureus or vancomycin-resistant enterococci can be detected on the protective gowns and gloves of up to 67% of health care workers tested. With the increasing prevalence of antibiotic-resistant organisms and nosocomial infections, it is important that techniques be used to prevent the spread and possible cross-contamination of infection. This is especially true with any type of instillation therapy where outbreaks of infection have been traced back to facility contamination caused by the therapy itself. It is likely that such outbreaks could be prevented by better containment of splatter during the instillation procedure. In addition to the treatment of infection, there are a number of other potential uses for instillation therapy. The medical and scientific community recognizes additional clinical benefits for instillation therapy. Nagai et al reported that instilling the protein sericin has a potent effect on wound healing and corneal epithelialization in a rodent model. Jerome suggested using instillation therapy to provide pain management during and after dressing changes. The addition and removal of a liquid solution from a wound bed may have other clinical benefits. Instilling a wound with lactated Ringer’s solution or saline may dilute the bioburden and prevent potential clinical infections. At the same time, instillation therapy with saline may help remove necrotic tissues and reduce the level of proinflammatory mediators, leading to a shift toward the proliferative phase of healing. Reducing the amount of early inflammation may also lead to better tissue remodeling and tissue quality. Recently, Acosta et al postulated that chronic and hyperinflammation is detrimental to the repair of diabetic foot wounds. They highlighted the need for smart prophylactic interventions to reduce chronic inflammation. We believe that instillation therapy may address this clinical need for a therapeutic intervention. In summary, there are many benefits to applying instillation therapy in the treatment of wounds including lower extremity wounds. Depending on what solution is being instilled, instillation therapy can help resolve clinical infections, manage pain, reduce bioburden, and may even potentially aid in epithelialization. All these clinical benefits will help

Vaccines and Immunotherapy for Staphylococcal Infections

Nosocomial or hospital-acquired infections are associated with prolonged hospitalizations and increased healthcare costs. Infections associated with surgical implants are becoming more difficult and more costly to manage, as they require repeated surgical procedures and a longer period of time to treat patients. Continued advances in the use of medical devices, an increase in the number of immunocompromised patients, and a steady rise in the prevalence of antibiotic-resistant organisms has renewed interest in the development of novel therapies that can be used to prevent and treat nosocomial infections. This review provides an overview of bacterial adhesins and focuses on novel immunological therapies developed to treat staphylococcal infections.

Composition and antibiotic resistance profile of microcosm dental plaques before and after exposure to tetracycline

The aim of this study was to investigate the effects of tetracycline administration on the viability and antibiotic resistance profiles of microcosm dental plaques. A constant depth film fermenter was used to generate multi-species biofilms, which were grown for 216 h before tetracycline was added. The composition of the microcosm plaques was determined by viable counting on selective and non-selective media. The prevalence of antibiotic-resistant organisms was determined on antibiotic-containing media. Before administration of tetracycline, the biofilms had a total viable anaerobic count of 7 x 10(7) cfu per biofilm. They contained 7% lactobacilli, 19% streptococci and 2% Actinomyces spp. Immediately after pulsing with tetracycline, the composition of the biofilms changed and they consisted of 30% lactobacilli, 1.5% streptococci and 3% Actinomyces spp., with a total anaerobic count of 1 x 10(7) cfu per biofilm. The pre-valence and composition of the antibiotic-resistant microflora changed dramatically after the addition of tetracycline, with the proportion of the microflora displaying resistance to tetracycline increasing from 6% to 45%. Corresponding changes in the proportions of the microflora displaying resistance to other antibiotics were as follows: 5-28% for erythromycin, 1-5% for vancomycin and 0.4-3% for ampicillin. The results of this study have shown that the addition of tetracycline to microcosm dental plaques alters their composition and enriches for bacteria resistant to tetracycline and other unrelated agents.

Two-Stage Exchange Hip Arthroplasty for Deep Infection

Although the risk of infection after total hip arthroplasty has decreased over the last three decades with the use of prophylactic antibiotics, laminar airflow operating rooms and whole-body exhaust suites, deep infection after total hip arthroplasty remains a serious complication. Significant morbidity to the patient and the cost to the health care system remain. During this period of time, diagnostic techniques also have improved including the use of polymerase chain reaction amplification. Treatment options now include: suppressive antibiotics, irrigation and debridement with retention of components, one-stage reimplantation, two-stage reimplantation, and salvage procedures. Based on the medical literature, the successful eradication of a total joint replacement infection with a two-stage reimplantation protocol is over 90% while the success rate with a one-stage protocol is approximately 80%. These success rates may decline however as the prevalence of antibiotic resistant organisms increases. Current controversies regarding two-stage reimplantation protocols include: duration of intravenous antibiotic therapy, timing of the reimplantation, the use of allograft bone in the reconstruction, the choice of fixation (cement versus cementless), and the use of antibiotic-loaded cement spacers.