Prior to 1992,<unk>  were relatively uncommon in the U.S. According to data from the National Nosocomial Infection Service, between 1986 and 1990, only 2.3% of 1825<unk>  isolates sampled were found to be resistant. According to the U.S. Centers for Disease Control,<unk>  producing what was the most common type of<unk> -destroying enzyme in 2001 were first detected in a North Carolina hospital in 1996. Since then, they have been identified in health care facilities in 41 other states. In 2012, 3% of patients in Chicago-area ICUs carried<unk> . The same data indicated a 30% colonization rate in long-term care facilities (e.g. nursing homes), where patients are not symptomatic. During just the first half of 2012, almost 200 hospitals and long-term acute care facilities treated at least one patient infected with these bacteria.<unk>  have become increasingly common in the US. The Meropenem Yearly Susceptibility Test Information Collection Program noted that resistance within K. pneumoniae alone increased from 0.6% in 2004 to 5.6% in 2008. The first outbreak involving colistin-resistant,<unk> -resistant K. pneumoniae (CRKP) in the U.S. was discovered in Detroit, Michigan in 2009, involving three different healthcare institutions. In an active surveillance study in seven U.S. states over two years, the crude overall incidence of<unk>  was 2.93 per 100,000 population. Georgia and Maryland had a significantly higher than predicted incidence adjusted for age and race. Increases in<unk>  have not been limited to the US. By 2011,<unk>  was reported in at least 22 countries. Between 2009 and 2012, 10 cases of<unk>  infections were documented in ICU patients in a Melbourne, Australia, hospital. Some cases of<unk>  are associated with receipt of medical care in the US. Strains found in Israel had genetic similarity to strains from the US. Hospital handwashing stations were found to be environmental reservoirs for<unk>  after screening all wet-area locations, including sinks, water fountains, and ice machines. The main reservoirs for<unk>  were the ICU sinks, and inappropriate cleaning methods accounted for transmission from sink to sink. The<unk>  strains in the sinks and the strains infecting the ICU patients were identical per genetic analysis. At-risk patients were being infected in the hospital setting. Mortality<unk>  resistance depends upon a number of factors such as the health of the patient, whether the patient has recently undergone a transplant, risk of co-infection, and use of multiple antibiotics.<unk>  minimal inhibitory concentrations (MICs) results may be more predictive of clinical patient outcomes than the current categorical classification of the MICs being listed as susceptible, intermediate, or resistant. The study aimed to define an all-cause hospital mortality breakpoint for<unk>  MICs that were adjusted for risk factors. Another objective was to determine if a similar breakpoint existed for indirect outcomes, such as the time to death and length of stay after infection for survivors. Seventy-one patients were included, of which 52 patients survived and 19 patients died. Classification and regression tree analysis determined a split of organism MIC between 2 and 4 mg/liter and predicted differences in mortality (16.1% for 2 mg/liter versus 76.9% for 4 mg/liter). In logistic regression controlling for confounders, each imipenem MIC doubling dilution doubled the probability of death. This classification scheme correctly predicted 82.6% of cases. Patients were accordingly stratified to MICs of ≤2 mg/liter (58 patients) and ≥4 mg/liter (13 patients). Patients in the group with a MIC of ≥4 mg/liter tended to be more ill. Secondary outcomes were also similar between groups. Patients with organisms that had an MIC of ≥4 mg/liter had worse outcomes than those with isolates of an MIC of ≤2 mg/liter. At New York Presbyterian Hospital, part of Columbia University Medical Center in New York, NY, a study was conducted on the significant rise in<unk>  resistance in K. pneumoniae from 1999 to 2007. Following a positive blood culture from a patient, overall mortality was 23% in 7 days, 42% in 30 days, and 60% by the end of hospitalization. The overall in-hospital mortality rate was 48%. At Soroka Medical Center, an Israeli university teaching hospital, a study was done between October 2005 and October 2008 to determine the direct mortality rate associated with<unk> -resistant K. pneumoniae bloodstream infections. The crude mortality rate for those with the resistant bacteremia was 71.9%, and the attributable mortality rate was determined to be 50% with a 95% confidence interval. The crude mortality rate for control subjects was 21.9%. As a result of the study, Soroka Medical Center started an intensive program designed to prevent the spread of<unk> -resistant K. pneumoniae. A 2013 retrospective study at the Shaare Zedek Medical Center of patients with urinary tract infections (bacteriuria) caused by<unk> -resistant Klebsiella pneumoniae (CRKp) showed no statistically significant difference in mortality rates from patients with bacteriuria caused by<unk> -susceptible K. pneumoniae (CSKp). A 29% mortality rate was seen in patients with CRKp infection compared to a 25% mortality rate in patients with CSKp infections that produced extended-spectrum beta-lactamase (ESBL). Both mortality rates were considerably higher than that of patients with drug-susceptible urosepsis. Most patients in the study suffered from other illnesses, including dementia, immune compromise, kidney failure, or diabetes mellitus. The main risk factor for death found by the study was being bedridden, which significantly increased the chance of death. This suggests that the deaths were due to reasons other than bacteriuria. Total length of hospitalization was somewhat longer in patients with CRKp infections (28 ± 33 days compared to 22 ± 28 days for patients with CSKp infection). In a case-control study of 99 patients compared with 99 controls at Mount Sinai Hospital (Manhattan), a 1,171 bed tertiary care teaching hospital, 38% of patients in long-term care that were afflicted with<unk>  died from K. pneumoniae infection. Patients had risk factors including diabetes, HIV infection, heart disease, liver disease, chronic kidney disease, one was a transplant recipient. 72% of patients who were released from the hospital with<unk>  were readmitted within 90 days. A 2008 study at Mount Sinai identified outcomes associated with<unk> -resistant Klebsiella pneumoniae infections, in which patients in need of organ or stem cell transplants, mechanical ventilation, prolonged hospitalization, or prior treatment with<unk> s, had an increased probability of infection with<unk> -resistant K. pneumoniae. A combination of antibiotics worked to treat infection and survival rates of infected patients increased when the focus of infection was removed.<unk>  infections can set in about 12 days after liver transplantation, and 18% of those patients died a year after transplantation in a 2012 study.
Carbapenem-resistant enterobacteriaceae
Vancomycin-resistant Enterococcus
Shigatoxigenic and verotoxigenic Escherichia coli
Vancomycin-resistant Staphylococcus aureus
Methicillin-resistant Staphylococcus aureus
Rapid growing mycobacterium
Isolated levocardia
Enteroinvasive Escherichia coli