Daptomycin versus vancomycin for bloodstream infections due to methicillin-resistant Staphylococcus aureus with a high vancomycin minimum inhibitory concentration: a case-control study.

BACKGROUND: Reports have found a link between vancomycin treatment failure in methicillin-resistant Staphyloccocus aureus (MRSA) bloodstream infections (BSIs) and higher vancomycin minimum inhibitory concentrations (MICs), despite MICs being below the susceptibility breakpoint of 2 µg/mL. Consensus guidelines recommend considering use of alternative agents for infections involving a higher vancomycin MIC, despite few data to support this approach. METHODS: This retrospective case-control study evaluated the effectiveness and safety of vancomycin, compared with that of daptomycin, in the treatment of MRSA BSIs with a high vancomycin MIC (ie, >1 µg/mL). RESULTS: A total of 118 vancomycin-treated subjects were compared with 59 daptomycin-treated subjects. Clinical failure, defined compositely as mortality, microbiologic failure, and/or recurrence of infection, was numerically lower in daptomycin-treated subjects (31% vs 17%; P = .084) and was mainly driven by a lower incidence of mortality in the daptomycin group (20% vs 9%; P = .046). Factors independently associated with clinical failure included acute renal failure (odds ratio [OR], 3.91 [95% confidence interval {CI}, 1.05-14.56]) and vancomycin treatment group (OR, 3.13 [95%, CI, 1.00-9.76]). Right-sided endocarditis was independently associated with clinical success (OR, 0.07 [95% CI, .01-.83]). A comparison of 60-day mortality between vancomycin- and daptomycin-treated subjects found a higher probability of survival in the daptomycin-treated group (P = .022). CONCLUSIONS: The results demonstrated that daptomycin was associated with a better outcome compared with vancomycin for the treatment of BSIs due to MRSA with higher vancomycin MICs. These findings support the recommendations of recent guidelines, which suggest consideration of the switch to alternative agents when the isolate has a high vancomycin MIC or when patients are not improving during receipt of therapy.

Prediction of failure in vancomycin-treated methicillin-resistant Staphylococcus aureus bloodstream infection: a clinically useful risk stratification tool.

Methicillin-resistant Staphylococcus aureus (MRSA) is a common cause of bloodstream infection (BSI) and is often associated with invasive infections and high rates of mortality. Vancomycin has remained the mainstay of therapy for serious Gram-positive infections, particularly MRSA BSI; however, therapeutic failures with vancomycin have been increasingly reported. We conducted a comprehensive evaluation of the factors (patient, strain, infection, and treatment) involved in the etiology and management of MRSA BSI to create a risk stratification tool for clinicians. This study included consecutive patients with MRSA BSI treated with vancomycin over 2 years in an inner-city hospital in Detroit, MI. Classification and regression tree analysis (CART) was used to develop a risk prediction model that characterized vancomycin-treated patients at high risk of clinical failure. Of all factors, the Acute Physiology and Chronic Health Evaluation II (APACHE-II) score, with a cutoff point of 14, was found to be the strongest predictor of failure and was used to split the population into two groups. Forty-seven percent of the population had an APACHE-II score < 14, a value that was associated with low rates of clinical failure (11%) and mortality (4%). Fifty-four percent of the population had an APACHE-II score ≥ 14, which was associated with high rates of clinical failure (35%) and mortality (23%). The risk stratification model identified the interplay of three other predictors of failure, including the vancomycin MIC as determined by Vitek 2 analysis, the risk level of the source of BSI, and the USA300 strain type. This model can be a useful tool for clinicians to predict the likelihood of success or failure in vancomycin-treated patients with MRSA bloodstream infection.

Human and swine hosts share vancomycin-resistant Enterococcus faecium CC17 and CC5 and Enterococcus faecalis CC2 clonal clusters harboring Tn1546 on indistinguishable plasmids.

VRE isolates from pigs (n = 29) and healthy persons (n = 12) recovered during wide surveillance studies performed in Portugal, Denmark, Spain, Switzerland, and the United States (1995 to 2008) were compared with outbreak/prevalent VRE clinical strains (n = 190; 23 countries; 1986 to 2009). Thirty clonally related Enterococcus faecium clonal complex 5 (CC5) isolates (17 sequence type 6 [ST6], 6 ST5, 5 ST185, 1 ST147, and 1 ST493) were obtained from feces of swine and healthy humans. This collection included isolates widespread among pigs of European Union (EU) countries since the mid-1990s. Each ST comprised isolates showing similar pulsed-field gel electrophoresis (PFGE) patterns (≤6 bands difference; >82% similarity). Some CC5 PFGE subtype strains from swine were indistinguishable from hospital vancomycin-resistant enterococci (VRE) causing infections. A truncated variant of Tn1546 (encoding resistance to vancomycin) and tcrB (coding for resistance to copper) were consistently located on 150- to 190-kb plasmids (rep(pLG1)). E. faecium CC17 (ST132) isolates from pig manure and two clinical samples showed identical PFGE profiles and contained a 60-kb mosaic plasmid (rep(Inc18) plus rep(pRUM)) carrying diverse Tn1546-IS1216 variants. The only Enterococcus faecalis isolate obtained from pigs (CC2-ST6) corresponded to a multidrug-resistant clone widely disseminated in hospitals in Italy, Portugal, and Spain, and both animal and human isolates harbored an indistinguishable 100-kb mosaic plasmid (rep(pRE25) plus rep(pCF10)) containing the whole Tn1546 backbone. The results indicate a current intra- and international spread of E. faecium and E. faecalis clones and their plasmids among swine and humans.

Evaluation of risk factors for coinfection or cocolonization with vancomycin-resistant enterococcus and methicillin-resistant Staphylococcus aureus.

We retrospectively evaluated 410 patients with coinfection or cocolonization due to vancomycin-resistant (VR) enterococcus (VRE) and methicillin-resistant Staphylococcus aureus (MRSA). The prevalence rate was 19.8%. Risk factors included isolation of VR Enterococcus faecalis and use of linezolid or clindamycin. Inc18-like vanA plasmids were found in 7% of VR E. faecalis isolates and none of the VR E. faecium isolates.

Characterization of vancomycin-resistant Enterococcus faecium isolated from swine in three Michigan counties.

Vancomycin-resistant enterococci are a major cause of nosocomial infections but are rarely found in humans in the community and have not been identified in food animals in the United States. We evaluated a total of 360 fecal specimens from humans and their animals being raised for exhibit at three county fairs in Michigan. Fecal samples from 158 humans, 55 swine, 50 cattle, 25 horses, 57 sheep, 14 goats, and 1 llama were obtained and plated onto Enterococcosel agar containing 16 µg/ml of vancomycin. Vancomycin-resistant Enterococcus faecium (VREF) was isolated from six pigs but not from humans or any animal other than pigs. All six VREF isolates had a MIC to vancomycin of ≥256 µg/ml and contained the vanA gene. Pulsed-field gel electrophoresis (PFGE) patterns of the six VREF isolates were ≥80% similar. Multilocus sequence typing (MLST) revealed sequence type 5 (ST5) (n = 2), ST6 (n = 3), and ST185 (n = 1), which are E. faecium sequence types belonging to clonal complex 5 (CC5). These findings show the dissemination of VREF strains among pigs in three Michigan counties. This is the first report of VRE found in food animals in the United States.

Clinical and economic outcomes for patients with health care-associated Staphylococcus aureus pneumonia.

While the increasing importance of methicillin-resistant Staphylococcus aureus (MRSA) as a pathogen in health care-associated S. aureus pneumonia has been documented widely, information on the clinical and economic consequences of such infections is limited. We retrospectively identified all patients admitted to a large U.S. urban teaching hospital between January 2005 and May 2008 with pneumonia and positive blood or respiratory cultures for S. aureus within 48 h of admission. Among these patients, those with suspected health care-associated pneumonia (HCAP) were identified using established criteria (e.g., recent hospitalization, admission from nursing home, or hemodialysis). Subjects were designated as having methicillin-resistant (MRSA) or methicillin-susceptible (MSSA) HCAP, based on initial S. aureus isolates. Initial therapy was designated "appropriate" versus "inappropriate" based on the expected susceptibility of the organism to the regimen received. We identified 142 patients with evidence of S. aureus HCAP. Their mean (standard deviation [SD]) age was 64.5 (17) years. Eighty-seven patients (61%) had initial cultures that were positive for MRSA. Most ( approximately 90%) patients received appropriate initial antibiotic therapy (86% for MRSA versus 91% for MSSA; P = 0.783). There were no significant differences between MRSA and MSSA HCAP patients in mortality (29% versus 20%, respectively), surgery for pneumonia (22% versus 20%), receipt of mechanical ventilation (60% versus 58%), or admission to the intensive care unit (79% versus 76%). Mean (SD) total charges per admission were universally high ($98,170 [$94,707] for MRSA versus $104,121 [$91,314]) for MSSA [P = 0.712]). Almost two-thirds of patients admitted to hospital with S. aureus HCAP have evidence of MRSA infection. S. aureus HCAP, irrespective of MRSA versus MSSA status, is associated with significant mortality and high health care costs, despite appropriate initial antibiotic therapy.

Epidemiology of Staphylococcus aureus colonization in nursing home residents.

BACKGROUND: We sought to characterize the clinical and molecular epidemiologic characteristics of Staphylococcus aureus colonization (especially extranasal colonization) and to determine the extent to which community-associated methicillin-resistant S. aureus (MRSA) has emerged in community nursing homes. METHODS: The study enrolled a total of 213 residents, with or without an indwelling device, from 14 nursing homes in southeastern Michigan. Samples were obtained from the nares, oropharynx, groin, perianal area, wounds, and enteral feeding tube site. Standard microbiologic methods were used to identify methicillin-susceptible S. aureus and MRSA. Molecular epidemiologic methods included pulsed-field gel electrophoresis, PCR detection of Panton-Valentine leukocidin, and SCCmec and agr typing. RESULTS: One hundred thirty-one residents (62%) were colonized with S. aureus (MRSA colonization in 86). S. aureus colonization occurred in 80 (76%) of 105 residents with indwelling devices and in 51 (47%) of 108 residents without indwelling devices (P<.001). Of the 86 residents who were colonized with MRSA, nares culture results were positive for only 56 (65%). Residents with devices in place were more likely to be colonized at multiple sites. Eleven different strains of MRSA were identified by pulsed-field gel electrophoresis. Seventy-three residents (85%) were colonized with hospital-associated SCCmec II strains, and 8 (9%) were colonized with community-associated SCCmec IV strains, 2 of which carried Panton-Valentine leukocidin. CONCLUSIONS: Extranasal colonization with MRSA is common among nursing home residents-particularly among residents with an indwelling device. We documented the emergence of community-associated SCCmec IV MRSA strains in the community nursing home setting in southeastern Michigan.

Molecular epidemiology of methicillin-resistant Staphylococcus aureus bloodstream isolates in urban Detroit.

To gain a better understanding of epidemiology of resistance in Staphylococcus aureus, we describe the molecular epidemiology of methicillin-resistant Staphylococcus aureus bloodstream isolates in urban Detroit. Bloodstream isolates from July 2005 to February 2007 were characterized. Two hundred ten bloodstream isolates from 201 patients were evaluated. Patient characteristics were as follows: median age, 54 years; 56% male; and 71% African-American. Seventy-six percent of infections were health care associated, with 55% being community-onset infections and 21% hospital acquired, and 24% were community associated. The most common sources were skin/wound (25%), central venous catheters (24%), unknown source (20%), and endocarditis (9%). Ninety percent and 5% of isolates had a MIC of vancomycin of or=1.5 mg/liter. Results of pulsed-field gel electrophoresis showed 17 strain types. The predominant strains were USA100 (104 isolates) and USA300 (74 isolates). Forty-nine percent of the isolates had staphylococcal cassette chromosome mec II, and 56% had agr II. All USA300 isolates were positive for the Panton-Valentine leukocidin toxin genes and agr I. Forty-seven percent of USA300 bloodstream infections were health care associated (35% community onset and 12% hospital onset). USA300 strains were more common in injection drug users with skin/wound as the predominant source of infection. Thirty percent of the USA100 strains were closely related to vancomycin-resistant Staphylococcus aureus isolates. The results of this study show that vancomycin MICs using automated dilution testing with Vitek-2 and E-test were highly discordant. Most methicillin-resistant S. aureus strains causing bacteremia are health care associated, commonly have MICs of vancomycin that are high within the susceptible range are not detected by routine automated dilution testing, and have significant diversity of molecular characteristics. USA100 strains that are closely related to vancomycin-resistant S. aureus (VRSA) isolates and USA300 strains are common as causes of both hospital and community-onset infection. Infection control measures should focus not only on prevention of the spread of community strains in the hospital but also prevention of the spread of hospital strains associated with VRSA into the community.

Heterogeneity of vat(E)-carrying plasmids in Enterococcus faecium recovered from human and animal sources.

In this study, quinupristin/dalfopristin (Q/D)-resistant Enterococcus faecium isolates (33 from poultry farms and 1 from a human outpatient) with Q/D minimal inhibitory concentrations ranging from 4 microg/mL to 32 microg/mL were analysed. Polymerase chain reaction detected the presence of vat(E) in all isolates. Using pulsed-field gel electrophoresis (PFGE), 14 distinct PFGE patterns were identified. The human E. faecium isolate was distinguishable from the 33 farm isolates by PFGE. Southern hybridisation localised the vat(E) gene to an 11 kb plasmid and resulted in five plasmid hybridisation types. The vat(E)-carrying plasmid from the human isolate showed a nearly identical hybridisation pattern to a plasmid from a farm isolate. This study showed that the vat(E) gene, conferring resistance to Q/D, was carried on different plasmids in a heterogeneous group of E. faecium, some of which may be acquired by E. faecium capable of infecting humans.

Quinupristin-dalfopristin resistance in gram-positive bacteria: mechanism of resistance and epidemiology.

Antimicrobial resistance in gram-positive bacteria is a continuing problem resulting in significant morbidity, mortality, and cost. Because of this resistance, new antimicrobial agents have been needed. Quinupristin-dalfopristin is a recently approved agent for treatment of these infections. Shortly after its introduction into clinical medicine, resistance was reported. Resistance can occur by one or more of several mechanisms, including enzymatic modification, active transport of efflux mediated by an adenosine triphosphate-binding protein, and alteration of the target site. Resistance is rare in isolates of staphylococci and Enterococcus faecium from humans. Resistance is common in isolates recovered from food animals and is related to the use of virginiamicin as a feed additive. Considering the effect antimicrobial resistance has on human health, as well as its economic impact, measures to preserve the usefulness of these agents and delay the development of resistance are urgently needed.

Antimicrobial resistance in swine and chickens fed virginiamycin for growth promotion.

In a prospective controlled study, we evaluated pigs (5-month period) and chickens (11-week period) fed subtherapeutic levels of virginiamycin. A total of 13 Enterococcus faecium were isolated from 10 pigs and 17 from 8 chickens. There were 8 pulsed-field gel electrophoresis (PFGE) patterns in E. faecium isolates from pigs and 17 from chickens. Resistance to quinupristin/dalfopristin resistance occurred in 2 of 13 E. faecium from pigs and 2 of 17 E. faecium from chickens. There were no strains exhibiting high-level gentamicin (MIC> or =2000 microg/ml) or vancomycin resistance. There was no relative weight gain in animals that received virginiamycin. The mean weight increase for the pigs in the group fed virginiamycin was 107.6 lb vs. 126.4 lb in the group that did not receive virginiamycin (P=n.s.). Chickens fed virginiamycin had a mean weight increase of 1672 g vs. 1886 g in the group that did not receive virginiamycin (P=n.s.). There was no correlation between receipt of virginiamycin or weight gain and presence of quinupristin/dalfopristin-resistant strains.

Evaluation of in vitro susceptibility trends to vancomycin and daptomycin by strain type of Staphylococcus aureus causing bloodstream infections.

In total, 718 consecutive clinical meticillin-resistant Staphylococcus aureus (MRSA) isolates from 2006 to 2010 and 417 clinical meticillin-susceptible S. aureus (MSSA) isolates from mid-2007 to 2010 were evaluated. Isolates were from blood cultures obtained from separate patients in Detroit, MI, and were tested for in vitro susceptibility trends to vancomycin and daptomycin by molecular strain type. The MRSA pulsed-field gel electrophoresis (PFGE) results showed that 290 (40.4%) were USA100, 296 (41.2%) were USA300 and the remaining isolates were non-USA100/300. Vancomycin minimum inhibitory concentrations (MICs) by Etest [mean±standard deviation (S.D.) 1.55±0.26mg/L] in MRSA isolates showed no significant change over the 5-year period within all strain types, whilst daptomycin MICs by Etest (mean±S.D. 0.51±0.25mg/L) showed a significant downward trend across time (r=-0.243; P<0.001), with this trend occurring among all PFGE groups. For MSSA, a significant decrease in MICs to vancomycin was found by Etest (r=-0.160; P=0.001) and conversely a significant increase in daptomycin MICs by Etest was found (r=0.146; P=0.028). The results of this study showed that changes in MIC were not specific to strain molecular type. For vancomycin, there was no change in MRSA MICs and a decrease in MSSA MICs for blood isolates. For daptomycin, MICs decreased in MRSA and increased in MSSA blood isolates over the study period.

Staphylococcus aureus meningitis: case series and literature review.

Staphylococcus aureus meningitis is a challenging disease and little is known about its epidemiology. There are no established management guidelines. We retrospectively reviewed the clinical information, bacteriologic data, and outcomes of all 33 patients with cerebrospinal fluid (CSF) cultures positive for S aureus seen at a single urban teaching hospital from 1999 to 2008. Pulsed-field gel electrophoresis (PFGE) and polymerase chain reaction for staphylococcal cassette chromosome mec (SCCmec), accessory gene regulator (agr) typing, and Panton-Valentine leukocidin (PVL) loci were done on methicillin-resistant S aureus (MRSA) CSF isolates starting in 2005. S aureus caused 12 (36%) cases of postoperative and 21 (64%) cases of hematogenous meningitis. MRSA isolates were found in 6 (50%) cases of postoperative and 10 (48%) cases of hematogenous meningitis. Twelve (75%) of the 16 MRSA infections occurred in the last 5 years of the study. Hematogenous meningitis was associated with older age (p = 0.04), injection drug use (p < 0.01), community-acquired infection (p < 0.01), underlying disease (p = 0.01), staphylococcal infection outside the central nervous system (p = 0.01), altered mental status (p = 0.02), fever (p = 0.01), septic shock (p = 0.03), and bacteremia (p < 0.01). The analysis of the 9 MRSA isolates showed 3 PFGE types: 3 USA100 (33%), 5 USA300 (56%), and 1 USAnot100-1100 (11%). For SCCmec typing, there were 2 (22%) type II and 7 (78%) type IV. All USA300 strains were SCCmec IVa. For agr typing, there were 5 (56%) type I and 4 (44%) type II. Three isolates (33%) were positive for the PVL gene and were USA300 strains. Most patients received nafcillin or vancomycin with or without rifampin or trimethoprim/sulfamethoxazole for a mean period of 17 days (range, 1-42 d). Overall mortality was 36%, and it was associated with community-acquired infection (p = 0.02). Postoperative and hematogenous S aureus meningitis are distinct clinical syndromes. S aureus hematogenous meningitis has devastating clinical consequences and elevated mortality rates, especially if it is acquired in the community. The incidence of MRSA meningitis increased over the last 5 years of the study. Treatment of choice is nafcillin for methicillin-sensitive strains and vancomycin for MRSA strains. The addition of trimethoprim/sulfamethoxazole or rifampin to vancomycin is recommended in severe cases and community-acquired MRSA infections. Linezolid is also a good option due to its good CSF penetration and favorable case reports. The mortality rate is higher in infections acquired in the community.

Comparative evaluation of epidemiology and outcomes of methicillin-resistant Staphylococcus aureus (MRSA) USA300 infections causing community- and healthcare-associated infections.

Methicillin-resistant Staphylococcus aureus (MRSA) USA300 clone is commonly found in the community and is being increasingly reported in the healthcare setting. A retrospective analysis was conducted to compare the epidemiology and outcomes between community-associated (CA) and healthcare-associated (HA) USA300 MRSA infections. The study enrolled 160 subjects with USA300 MRSA infections (47.5% CA-MRSA and 52.5% HA-MRSA). Failure in the HA group was higher (38.1%) compared with the CA group (23.7%) (P=0.05). Predictors of failure included male gender, age, presence of any co-morbidity, coronary artery disease, chronic kidney disease, history of MRSA, previous admission, fluoroquinolone exposure, HA infection and osteomyelitis (P

Epidemiology of antimicrobial resistance in enterococci of animal origin.

OBJECTIVE: We evaluated the epidemiology of antimicrobial resistance in enterococci from animal farms and the potential relation of resistance to antimicrobial use. METHODS: Enterococci from faecal samples from 18 beef cattle, 18 dairy cattle, 18 swine, 13 chicken, and eight turkey farms were prospectively evaluated over a 6 year period from 1998 to 2003. RESULTS: We evaluated 1256 isolates of Enterococcus faecium and 656 isolates of Enterococcus faecalis. None was vancomycin resistant. Quinupristin/dalfopristin, gentamicin and ciprofloxacin resistance rates in E. faecium were 2%, 0% and 55% in beef cattle, 8%, 7% and 47% in dairy cattle, 21%, 1% and 47% in swine, 85%, 12% and 23% in chicken, and 52%, 13% and 24% in turkey isolates, respectively. For E. faecalis, gentamicin resistance rates were 0% in beef cattle, 24% in dairy cattle, 37% in swine, 32% in chicken, and 29% in turkey isolates, whereas 12%, 9%, 21%, 64% and none of isolates from beef, dairy, swine, chicken, and turkey farms, respectively, were resistant to ciprofloxacin. Quinupristin/dalfopristin resistance in E. faecium was more common on chicken and turkey farms using virginiamycin (P<0.0001 for both) compared with farms not using a streptogramin, gentamicin resistance was more common on dairy farms using gentamicin (P<0.0001) compared with farms not using this antibiotic, and ciprofloxacin resistance was more common on turkey and dairy farms using enrofloxacin compared with those with no enrofloxacin use (P=0.02 and P=0.04, respectively). For E. faecalis, gentamicin resistance was more frequently detected on dairy and swine farms using gentamicin (P<0.0001 and P=0.0052, respectively) and ciprofloxacin resistance was more common on beef farms using enrofloxacin (P<0.0001) compared with farms not using these antimicrobials. PFGE showed multiple strain types with some clones common between animals of the same animal species. CONCLUSIONS: This study shows the presence of a significant reservoir of antibiotic-resistant enterococci among farm animals. Resistance was more common on farms using antimicrobial agents.

Multiplex PCR for detection of aminoglycoside resistance genes in enterococci.

A multiplex PCR procedure for detecting the aminoglycoside resistance genes aac(6')-Ie-aph(2")-Ia, aph(2")-Ib, aph(2")-Ic, aph(2")-Id, aph(3')-IIIa, and ant(4')-Ia was evaluated and found to determine accurately the presence of these genes in enterococci.

Comparison of microscan broth microdilution, synergy quad plate agar dilution, and disk diffusion screening methods for detection of high-level aminoglycoside resistance in enterococcus species.

We compared the dried MicroScan microdilution panel, Synergy Quad plate agar dilution, and high-potency disk diffusion screening methods for the detection of high-level aminoglycoside resistance in 815 enterococcal bloodstream isolates. Agreement between the three methods was 99% when testing for high-level gentamicin resistance and 96% when testing for high-level streptomycin resistance.

Molecular and clinical epidemiology of vancomycin-resistant Enterococcus faecalis.

OBJECTIVES: With the recent emergence of vancomycin-resistant (VR) Staphylococcus aureus, subsequent to the suggested transfer of the vanA resistance gene from Enterococcus faecalis, we sought to determine risk factors for acquisition of VR E. faecalis and to evaluate the molecular epidemiology of this less-prevalent and less-studied species of VR enterococcus. METHODS: We compared clinical isolates of VR E. faecalis from 71 patients, collected over 12 years in a large community teaching hospital, with isolates from 126 patients with vancomycin-susceptible E. faecalis. RESULTS: Risk factors for VR E. faecalis acquisition by multivariate analysis were nursing home residence (P = 0.0005), haemodialysis (P = 0.009), decubitus ulcers (P = 0.03) and receipt of parenteral vancomycin (P = 0.0002). Twenty-one percent of VR E. faecalis demonstrated vanA and 79% vanB resistance. The number of VanA isolates increased over time. Molecular analysis showed vanA or vanB in multiple PFGE groups. CONCLUSIONS: The results of this study suggest gene dissemination among some isolates and intra-hospital spread of other isolates. The risk factors identified clearly suggest that VR E. faecalis is a nosocomial pathogen and should be considered in infection control practices. Further surveillance of VR E. faecalis is warranted, due to the potential spread of vancomycin resistance among enterococci and staphylococci.