Enterococcal pyogenic liver abscesses: high risk of treatment failure and mortality.

Enterococci are the most frequent gram-positive bacteria recovered from pyogenic liver abscesses (PLA). This study aims to analyze the impact of the presence of Enterococcus spp. on PLA outcome. We retrospectively analyzed the characteristics and outcome of all PLA cases in which Enterococcus spp. was isolated between January 2010 and September 2019 in a French university hospital and compared them to PLA without Enterococcus spp. Enterococci were recovered from 68 of the 359 (19%) PLA cases. Among the 78 isolates, Enterococcus faecalis (n = 37, 47.7%) and Enterococcus faecium (n = 32, 41%) were the most frequent. Enterococcal PLA were more often of biliary origin (79.4% versus 54.6%, p < 0.001) or post-surgical (35.3% versus 18.6%, p = 0.004). Multivariate analysis showed an independent association between the isolation of Enterococcus spp. and 3-month mortality (HR 2.51, p = 0.011), primary failure (HR 2.15, p = 0.006), but not with relapses (HR 0.86, p = 0.739). In the subgroup of enterococcal PLA, portal vein thrombosis was the only factor significantly associated with 3-month mortality (univariate HR 3.45, p = 0.023) or primary treatment failure (multivariate, HR 4.02, p = 0.006). Enterococcus spp. identification in a PLA is associated with a higher mortality and primary treatment failure.

Analysis of 15 cases from a monocentric cohort of 307 liver abscesses.

BACKGROUND: Out of the context of haematological patients, Candida sp. is rarely retrieved from pyogenic liver abscesses (PLA). OBJECTIVES: Our objective was to assess the risk factors for occurrence, and clinical, microbiological characteristics, management and outcome of Candida pyogenic liver abscesses (C-PLA). PATIENTS/METHODS: We retrospectively analysed C-PLA cases and compared them to pyogenic liver abscesses exclusively due to bacteria (B-PLA) included in our monocentric database on liver abscesses. Unfavourable course was defined as the occurrence of a primary treatment failure (PTF), recurrence after an initial cure, or death within 3 months after diagnosis. RESULTS: Between 2010 and 2018, 15 C-PLA and 292 B-PLA were included. All C-PLA had a biliary origin and were polymicrobial. All patients with C-PLA had at least one comorbidity at risk for Candida infection and 7 (53.3%) presented with sepsis requiring an admission in intensive care unit. Median duration of antifungal treatment was 42 days [24-55]. In multivariate analysis, compared with B-PLA, a medical history of malignancy (OR 4.16; 95%CI 1.15-18.72) or liver abscess (OR 7.39; 95%CI 2.10-26.62), and sepsis with severity criteria (OR 3.52; 95%CI 1.07-11.90) were independently associated with the occurrence of C-PLA. In multivariate analysis, C-PLA was associated with a higher risk of recurrence (HR 3.08; 95%CI 1.38-11.22). CONCLUSION: Candida liver abscesses in non-neutropenic is a rare and severe disease. The high rate of recurrence should lead to discuss a more intensive treatment.

Large retrospective study analysing predictive factors of primary treatment failure, recurrence and death in pyogenic liver abscesses.

PURPOSE: Pyogenic liver abscess (PLA) is a severe disease, which unfavourable evolution remains frequent. Our objective was to assess predictive factors of unfavourable outcome in patients with PLA. METHODS: We conducted a retrospective study in a French tertiary care centre. All patients admitted for PLA between 2010 and 2018 were included. Unfavourable course was defined as the occurrence of a primary treatment failure (PTF), recurrence of PLA after an initial cure, or death within 3 months after diagnosis. Hazard ratios (95% CI) were calculated with multivariable Cox proportional hazard models. RESULTS: 302 patients were included among which 91 (30.1%) patients had an unfavourable outcome because of PTF, recurrence or death in 55 (18.2%), 28 (9.2%) and 32 (10.6%) patients, respectively. Hepatic metastases (HR 2.08; 95% CI 1.04-4.15), a nosocomial infection (2.25; 1.14-4.42), portal thrombosis (2.12; 1.14-3.93), and the isolation of Enterococcus spp. (2.18; 1.22- 3.90) were independently associated with PTF. Ischemic cholangitis (6.30; 2.70-14.70) and the isolation of Streptococcus spp. (3.72; 1.36-10.16) were associated with the risk of recurrence. Charlson comorbidity index (HR 1.30 per one point; 95% CI 1.15-1.46; p < 0.001), portal thrombosis (3.53; 1.65-7.56) and the presence of multi-drug-resistant organisms (3.81; 1.73-8.40) were associated with mortality within 3 months following PLA diagnosis. PLA drainage was the only factor associated with a lower mortality (0.14; 0.06-0.34). CONCLUSION: Identification of specific risk factors may help to improve the management of PLA and to elaborate targeted recommendations according to patient's and disease's characteristics.

The challenges of multi-drug-resistance in hepatology.

Antimicrobial resistance has become a major global public health security problem that needs coordinated approaches at regional, national and international levels. Antibiotic overuse and the failure of control measures to prevent the spread of resistant bacteria in the healthcare environment have led to an alarming increase in the number of infections caused by resistant bacteria, organisms that resist many (multi-drug and extensively drug-resistant strains), if not all (pan-drug-resistant bacteria) currently available antibiotics. While Gram-positive cocci resistance (methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci) shows a heterogeneous geographical distribution, extended-spectrum ß-lactamase-producing Enterobacteriaceae and carbapenem-resistant Enterobacteriaceae have become pandemic worldwide and endemic in some parts of the world, respectively. Moreover, currently available therapeutic options for resistant bacteria are very limited, with very few new agents in development. Antimicrobial resistance is especially relevant in decompensated cirrhosis. Firstly, cirrhotic patients are highly susceptible to develop infections caused by resistant bacteria as risk factors of multiresistance concentrate in this population (mainly repeated hospitalizations and antibiotic exposure). Secondly, inappropriate empirical antibiotic schedules easily translate into increased morbidity (acute kidney injury, acute-on-chronic liver failure, septic shock) and hospital mortality in advanced cirrhosis. Therefore, hepatologists must face nowadays a complex clinical scenario that requires new empirical antibiotic strategies that may further spread resistance. Global, regional and local preventive measures should therefore be implemented to combat antimicrobial resistance in cirrhosis including the restriction of antibiotic prophylaxis to high-risk populations, investigation on non-antibiotic prophylaxis, stewardship programs on adequate antibiotic prescription and on increasing awareness of the problem among health professionals, and well-defined early de-escalation policies based on rapid microbiological diagnostic tests. Other infection control practices such as hand hygiene and barrier precautions are also important. Clinical impact and cost-effectiveness of epidemiological surveillance programs (periodic rectal and nasal swabs) should also be explored.

A new mechanism to render clinical isolates of Escherichia coli non-susceptible to imipenem: substitutions in the PBP2 penicillin-binding domain.

OBJECTIVES: So far, two types of mechanism are known to be involved in carbapenem non-susceptibility of Escherichia coli clinical isolates: reduced outer membrane permeability associated with production of ESBLs and/or overproduction of class C ß-lactamases; and production of carbapenemases. Non-susceptibility to only imipenem observed in two clinical isolates suggested a new mechanism, described in the present study. METHODS: The ST was determined for the two isolates of E. coli (strains LSNy and VSBj), and their chromosomal region encoding the penicillin-binding domain of PBP2 was amplified, sequenced and then used for recombination experiments in E. coli K12 C600. Antibiotic MICs were determined using the Etest method. RESULTS: Strains LSNy and VSBj, which displayed ST23 and ST345, respectively, showed amino acid substitutions in their PBP2 penicillin-binding domain. Substitution Ala388Ser located in motif 2 (SXD) was common to the two strains. Two additional substitutions (Ala488Thr and Leu573Val) located outside the two other motifs were identified in strain LSNy, whereas another one (Thr331Pro) located in motif 1 was identified in strain VSBj. Recombination experiments to reproduce non-susceptibility to imipenem in E. coli K12 C600 were not successful when only the common substitution was transferred, whereas recombination with DNA fragments including either the three substitutions (strain LSNy) or the two substitutions (strain VSBj) were successful. CONCLUSIONS: Substitution of amino acids in the penicillin-binding domain of PBP2 is a new mechanism by which E. coli clinical isolates specifically resist imipenem.

Epidemiology, treatment and outcomes of infected pancreatic necrosis in France: a bicenter study.

INTRODUCTION: Acute necrotizing pancreatitis (ANP) mortality increases when pancreatic necrosis is infected (IPN). Current treatment of IPN relies on prolonged antibiotic therapies associated with a step-up strategy of drainage. The objective of this study was to analyze IPN treatment outcomes in two referral centers in France. METHODS: Data of consecutive patients with documented IPN hospitalized in two expert centers in France between 2014 and 2019 were retrospectively reviewed. The composite primary outcome was the proportion of unsuccessful management outcome, defined as new emergency drainage to treat sepsis with organ failure, an unplanned new antibiotic course, an unplanned prolongation of antibiotic course and/or death by septic shock, within three months following the diagnosis of ANP. RESULTS: All in all, 187 patients (138 males; 74.0%), with documented IPN were included. The most frequently identified microorganism was Escherichia coli (26.2%). Ninety-eight patients (52.4%) were admitted to an intensive care unit or resuscitation ward within the first two days of ANP care. Overall, 126 patients (67.4%) endured an unsuccessful outcome: new emergency drainage to treat acute sepsis (62.0%), unplanned new antibiotic course (47.1%), unplanned prolongation of antibiotic course (44.9%) and/or death by septic shock complicating IPN (8.0%). CONCLUSION: The unfavorable evolution in two thirds of patients shows that determination of optimal drainage timing and choice of antibiotic therapy remain major challenges in 2024.

Community-acquired Klebsiella pneumoniae pneumonia in ICU: a multicenter retrospective study.

BACKGROUND: Alongside the recent worldwide expansion of hypervirulent Klebsiella pneumoniae (KP) infections, the available literature regarding cases of community acquired pneumonias (KP-CAP) remains scarce but reports a strikingly high and early mortality. We performed a retrospective multicenter study (7 ICU in France) between 2015 and 2019, comparing prognosis and severity of KP-CAP versus Streptococcus pneumoniae - CAP (SP-CAP). METHODS: For each KP-CAP, three SP-CAP admitted in ICUs within the same center and within the same 6-month window were selected. When available, KP strains were studied, and bacterial virulence was genetically assessed for virulence factors. The primary outcome was in-hospital mortality. Associations between clinical outcomes and type of infection were tested using univariate and multivariate logistic regressions, adjusted for pairing variables. RESULTS: Twenty-seven KP-CAP and 81 SP-CAP were included. Respective in-hospital mortality rates were 59% (n = 16) and 17% (n = 14, p < 0.001), despite adequate antibiotic therapy. KP-CAP median time from admission to death was 26.9 h [IQR 5.75-44 h] and were significantly associated with higher rates of multiple organ failures (93% vs. 42%, p < 0.001), disseminated intravascular coagulation (12% vs. 1.3%, p = 0.046), septic shock (median lactate on ICU admission 4.60 vs. 2.90 mmol/L, p = 0.030) and kidney failure (KDIGO-3: 87% vs. 44%, p < 0.001). Interestingly, alcoholism was the only identified predisposing factor of KP-CAP. Severity on ICU admission (2-fold higher for KP-CAP) was the only factor associated with mortality in a multivariate analysis. CONCLUSION: We described a strong association between KP-CAP infection and higher and earlier mortality when compared to SP-CAP. Moreover, alcoholism was the sole predisposing factor associated with KP-CAP infection. These findings should raise awareness of clinicians involved in the management of severe CAP about this microbiological etiology. Future prospective studies are needed to confirm these results and to design strategies to improve the prognosis of such infections.

Diagnosis and treatment of bacterial peritonitis in patients with gastrointestinal cancer: an observational multicenter study.

Background: Bacterial peritonitis (BP) in patients with gastrointestinal (GI) cancer has been poorly described, and its prevalence is unknown. Objectives: This study aimed to evaluate in patients with both GI cancer and ascites the prevalence of BP, associated features, mechanisms, prognosis, and the diagnostic performance of neutrophil count in ascites. Design: A retrospective, multicenter, observational study. Methods: All patients with GI cancer and ascites who underwent at least one paracentesis sample analyzed for bacteriology over a 1-year period were included. BP was defined by a positive ascites culture combined with clinical and/or biological signs compatible with infection. Secondary BP was defined as BP related to a direct intra-abdominal infectious source. Results: Five hundred fifty-seven ascites from 208 patients included were analyzed. Twenty-eight patients had at least one episode of BP and the annual prevalence rate of BP was 14%. Among the 28 patients with BP, 19 (65%) patients had proven secondary BP and 17 (59%) patients had multi-microbial BP, mainly due to Enterobacterales. A neutrophil count greater than 110/mm3 in ascites had negative and positive predictive values of 96% and 39%, respectively, for the diagnosis of BP. The median survival of patients with BP was 10 days (interquartile range 6-40) after the diagnosis. Conclusion: BP is not rare in patients with GI cancer and is associated with a poor short-term prognosis. When a patient with GI cancer is diagnosed with BP, a secondary cause should be sought. Further studies are needed to better define the best management of these patients.

10-Fold increase (2006-11) in the rate of healthy subjects with extended-spectrum ß-lactamase-producing Escherichia coli faecal carriage in a Parisian check-up centre.

OBJECTIVES: In 2006, 0.6% of healthy subjects living in the Paris area had extended-spectrum ß-lactamase (ESBL)-producing Escherichia coli in their gut. To assess the evolution of this rate, a study identical to that of 2006 was conducted in 2011. PARTICIPANTS AND METHODS: Healthy adults who visited the IPC check-up centre in February-March 2011 and agreed to participate, provided stools and answered a questionnaire on the visit day. Stools were analysed to detect ESBL producers and to isolate the dominant E. coli population. ESBLs were molecularly characterized. For the subjects harbouring ESBL-producing E. coli, the phylogenetic group and sequence type (ST) were determined for both ESBL-producing and dominant E. coli isolates. PFGE profiles were also determined when two types of isolates had the same ST. RESULTS: Among the 345 subjects included, 21 (6%) had ESBL-producing E. coli faecal carriage. None of the previously published risk factors was identified. CTX-M accounted for 86% and SHV-12 for 14%. Dominant and ESBL-producing E. coli were similarly distributed into phylogenetic groups (A, 52%-48%; B1, 5%; B2, 24%-14%; and D, 19%-33%). Dominant and ESBL-producing E. coli displayed a polyclonal structure (18 STs each). However, ST10 and ST131 were identified in dominant and ESBL-producing E. coli isolates from different subjects. Most (20/21) ESBL producers were subdominant and belonged (16/21) to STs different from that of the corresponding dominant E. coli. CONCLUSIONS: The 10-fold increase in the rate of healthy subjects with ESBL-producing E. coli faecal carriage over a 5 year period suggests wide dissemination of these isolates in the Parisian community.

First case of bloodstream infection due to Caulobacter spp. associated with a postoperative meningitis.

Caulobacter species are aerobic Gram-negative bacilli initially isolated from aquatic environments and are an uncommon cause of human infection. We report a case of bloodstream infection and postoperative meningitis caused by Caulobacter spp. that occurred in a 53-year old woman two weeks after surgery for a breast carcinoma cerebral metastasis. Polymerase chain reaction (PCR) amplification and sequencing of the 16 S ribosomal DNA identified Caulobacter spp. in three blood cultures and two cerebrospinal fluid (CSF) cultures. Based on our susceptibility results, the patient was successfully treated by a 2-week course of iv imipenem followed by a 4-week course of oral trimethoprim-sulfamethoxazole.

[Clinical and radiological differences between amoebic and pyogenic liver abscess: A case-control study]. / Analyse des différences cliniques et radiologiques entre abcès hépatiques amibiens et à pyogènes à partir d'une étude cas-témoin.

INTRODUCTION: Amoebic liver abscess (ALA) is the fourth cause of mortality by parasitic infection. This study aimed to assess clinical, radiological and therapeutic characteristics of patients admitted for amoebic liver abscess compared to pyogenic abscess in a French digestive tertiary care-centre. MATERIAL AND METHOD: The charts of patients hospitalized for a liver abscess between 2010 and 2020 were retrospectively assessed then separated in two groups: amoebic liver abscess and pyogenic liver abscess from portal underlying cause. Clinical and radiological data were collected for univariate comparison. RESULTS: Twenty-one patients were hospitalized during the time of the study for ALA, and 21 patients for pyogenic liver abscess with a portal mechanism. All patients hospitalized for ALA lived in and/or had travelled recently in an endemic area. In comparison with patients hospitalized for pyogenic abscess, patients admitted for ALA were younger (44years old vs. 63years old, P<0.001), had less comorbidities (5% vs. 43% of patients with at least one comorbidity, P<0.01), a longer median duration of symptoms (10days vs. 3days, P=0.015), abdominal pain (86% vs. 52%, P=0.019), and a slighter leucocytosis (9600G/L vs. 15,500G/L, P=0.041) were more frequent. On the abdominal tomodensitometry, density of ALA was higher (34 vs. 25 UH, P<0.01), associated with a focal intra-hepatic biliary dilatation and less often multiloculated. CONCLUSION: While rare in western countries, amoebic liver abscess care should not be underestimated. The presence of a solitary liver abscess of intermediate density on computed tomography, occurring on a patient returning from an endemic zone should lead the physician to a possible diagnosis of ALA.

Evaluation of the contribution of shotgun metagenomics in the microbiological diagnosis of liver abscesses.

BACKGROUND: Shotgun metagenomics (SMg) sequencing has gained a considerable interest, as it enables the detection of any microorganisms through a single analysis. Due to the limitations of standard microbiological approaches, the microbial documentation of liver abscesses (LA), which is crucial for their medical management, can be difficult. Here we aimed to compare the performance of SMg with standard approaches for the microbiological documentation of LA. METHODS: In this retrospective study conducted at two centers, we compared the results of standard microbiology with metagenomics analysis of consecutive LA samples. For samples tested positive for Klebsiella pneumoniae, we compared the analysis of virulence and resistance genes using metagenomics data to whole-genome sequencing of corresponding isolates obtained in culture. RESULTS: Out of the 62 samples included, standard approaches and SMg yielded documentation in 80.6% and 96.8%, respectively. In 37.1% (23/62) of cases, both methods showed identical results, whereas in 43.5% (27/62) of cases, the samples were positive by both methods, but SMg found additional species in 88.9% (24/27), mostly anaerobes. When the standard approaches were negative, the SMg was able to detect microorganisms in 80.0% of cases (8/10). Overall, SMg identified significantly more microorganisms than culture (414 vs.105; p<0.05). K. pneumoniae genome analysis was able to detect resistance and virulence genes with a level of sensitivity depending on the depth of sequencing. DISCUSSION: Overall, we showed that SMg had better performance in detecting and identifying microorganisms from LA samples and could help characterizing strain's resistome and virulome. Although still costly and requiring specific skills and expensive equipment, MGs methods are set to expand in the future.

Pretransplant fecal carriage of extended-spectrum ß-lactamase-producing Enterobacteriaceae and infection after liver transplant, France.

Extended-spectrum ß-lactamase-producing Enterobacteriaceae isolates (ESBLE) are emerging pathogens that confer resistance to antimicrobial drugs. We conducted a 10-year study in France (January 2001-April 2010) to investigate the incidence of and risk factors for ESBLE infections after liver transplant. Of 710 transplant patients screened preoperatively for ESBLE fecal carriage, 5.5% had ESBLE infection develop within 4 months after surgery; patients with pretransplant ESBLE fecal carriage were more likely to have infection develop than were noncarriers. Typing showed extensive genetic diversity, with a large predominance of CTX-M enzymes. Independent predictors of ESBLE infection were pretransplant fecal carriage, Model for End Stage Liver Disease score >25, and return to surgery. Our results indicate that the influx of preoperatively acquired ESBLE isolates into the hospital outweighs cross-transmission in the epidemiology of ESBLE infections after liver transplant. Transplant candidates should be systematically screened for carriage, and posttransplant infection in carriers should be treated with carbapenems.

Spontaneous and postsurgical/traumatic Klebsiella pneumoniae meningitis: two distinct clinico-microbiological entities.

OBJECTIVES: To analyze and compare the characteristics and outcomes of spontaneous meningitis (SM) versus postsurgical/traumatic meningitis (PSTM) due to Klebsiella pneumoniae. METHODS: A retrospective multicentric cohort study of all K. pneumoniae meningitis cases managed between January 2007 and May 2018 was carried out in seven university hospitals in the Paris area. The microbiological characteristics of 16 available K. pneumoniae isolates were further analyzed, and the genomes of seven of those isolated from SM were sequenced. RESULTS: Among 35 cases, 10 were SM and 25 were PSTM. SM cases more severe than PSTM cases, with higher septic shock (p = 0.004) and in-hospital mortality rates (p = 0.004). In contrast, relapse occurred in five patients from the PSTM group versus no patients from the SM group. All K. pneumoniae strains recovered from SM but none of those recovered from PSTM displayed hypervirulent phenotypic (positive string test) and genotypic (genes corresponding to capsular serotypes K1 or K2; virulence genes rmpA and iutA) characteristics (p < 0.0001). PSTM tended to be more frequently polymicrobial (p = 0.08) and caused by an extended-spectrum ß-lactamase producing strain (p = 0.08) than SM. CONCLUSIONS: SM and PSTM are two entities differing both from a clinical and a microbiological standpoint. SM appears to be a more serious infection, induced by hypervirulent K. pneumoniae strains.

In vitro selection of ramR and soxR mutants overexpressing efflux systems by fluoroquinolones as well as cefoxitin in Klebsiella pneumoniae.

The relationship between efflux system overexpression and cross-resistance to cefoxitin, quinolones, and chloramphenicol has recently been reported in Klebsiella pneumoniae. In 3 previously published clinical isolates and 17 in vitro mutants selected with cefoxitin or fluoroquinolones, mutations in the potential regulator genes of the AcrAB efflux pump (acrR, ramR, ramA, marR, marA, soxR, soxS, and rob) were searched, and their impacts on efflux-related antibiotic cross-resistance were assessed. All mutants but 1, and 2 clinical isolates, overexpressed acrB. No mutation was detected in the regulator genes studied among the clinical isolates and 8 of the mutants. For the 9 remaining mutants, a mutation was found in the ramR gene in 8 of them and in the soxR gene in the last one, resulting in overexpression of ramA and soxS, respectively. Transformation of the ramR mutants and the soxR mutant with the wild-type ramR and soxR genes, respectively, abolished overexpression of acrB and ramA in the ramR mutants and of soxS in the soxR mutant, as well as antibiotic cross-resistance. Resistance due to efflux system overexpression was demonstrated for 4 new antibiotics: cefuroxime, cefotaxime, ceftazidime, and ertapenem. This study shows that the ramR and soxR genes control the expression of efflux systems in K. pneumoniae and suggests the existence of efflux pumps other than AcrAB and of other loci involved in the regulation of AcrAB expression.

Detection of bacterial DNA in serum and ascitic fluid of asymptomatic outpatients with cirrhosis and non-neutrocytic ascites.

BACKGROUND AND AIMS: Bacterial DNA (bactDNA) has been found in serum and ascitic fluid (AF) of 30-40% of hospitalized patients with cirrhosis and non-neutrocytic ascites, but its prevalence in outpatients is unknown. The aim of this prospective study was to investigate the presence of bactDNA in AF and serum among cirrhotic outpatients with non-neutrocytic ascites. METHODS: Thirty-one consecutive patients with cirrhosis and non-neutrocytic ascites, who underwent therapeutic paracentesis in our outpatient clinic, were enrolled over a 13-week period. Of these patients, 13 had a single paracentesis and 18 patients had several consecutive paracenteses (2-10) over the study period. Overall, 98 serum and non-neutrocytic AF specimens were obtained and tested for the presence of bactDNA by polymerase chain reaction amplification of the 16S ribosomal RNA gene. RESULTS: The main causes of cirrhosis were alcohol (53.5%) and hepatitis C (30%). The median MELD score was 16 and there were 54.8% Child-Pugh C patients. BactDNA was negative in all samples from 28 of the 31 patients, including 15 patients with several paracentesis. One patient had a single AF sample culture positive and bactDNA positive for Streptococcus mitis, whereas the simultaneous blood sample was negative. For each of the last two patients, DNA from Lactococcus lactis was detected in a single blood sample but not in the simultaneous AF sample. CONCLUSIONS: In contrast to that reported previously in hospitalized patients, bactDNA is rarely detected in serum and AF of outpatients with cirrhosis and non-neutrocytic ascites.

Risk Factors and Impact of Perioperative Prophylaxis on the Risk of Extended-spectrum ß-Lactamase-producing Enterobacteriaceae-related Infection Among Carriers Following Liver Transplantation.

BACKGROUND: Extended-spectrum ß-lactamase-producing Enterobacteriaceae (ESBL-E) carriage is frequent among liver transplant (LT) recipients, thereby fostering a large empirical carbapenem prescription. However, ESBL-E infections occur in only 10%-25% of critically ill patients with rectal colonization. Our aim was to identify risk factors for post-LT ESBL-E infection in colonized patients. The effect of perioperative antimicrobial prophylaxis (AP) was also analyzed in patients with prophylaxis lasting <48 hours and without proven intraoperative infection. METHODS: Retrospective study from a prospective database including patients with a positive ESBL-E rectal screening transplanted between 2010 and 2016. RESULTS: Among the 749 patients transplanted, 100 (13.3%) were colonized with an ESBL-E strain. Thirty-nine (39%) patients developed an infection related to the same ESBL-E (10 pulmonary, 11 surgical site, 13 urinary, 5 bloodstream) within 11 postoperative days in median. Klebsiella pneumoniae carriage, model for end-stage liver disease ≥25, preoperative spontaneous bacterial peritonitis prophylaxis, and antimicrobial exposure during the previous month were independent predictors of ESBL-E infection. We propose a colonization to infection risk score built on these variables. The prevalence of infection for colonization to infection score of 0, 1, 2, and ≥3 were 7.4%, 26.3%, 61.9%, and 91.3%, respectively. Of note, the incidence of post-LT ESBL-E infection was lower in case of perioperative AP targeting colonizing ESBL-E (P = 0.04). CONCLUSIONS: Thirty-nine percentage of ESBL-E carriers develop a related infection after LT. We identified predictors for ESBL-E infection in carriers that may help in rationalizing carbapenem prescription. Perioperative AP targeting colonizing ESBL-E may be associated with a reduced risk of post-LT ESBL-E infections.

Genetic diversity and virulence profiles of Escherichia coli isolates causing spontaneous bacterial peritonitis and bacteremia in patients with cirrhosis.

Among patients with cirrhosis, infections caused by Escherichia coli organisms that translocate from the gut are a frequent and severe complication. One hundred ten E. coli isolates from 110 cirrhotic patients with spontaneous bacterial peritonitis and/or spontaneous bacteremia were characterized for their phylogenetic group and virulence genotype (34 extraintestinal virulence factor genes). Genetic relatedness was investigated by enterobacterial repetitive intergenic consensus sequence type 2 (ERIC-2) PCR typing and multilocus sequence typing. Phylogenetic groups A, B1, B2, and D accounted for 24%, 4%, 48%, and 24% of the population, respectively. Overall, 68 distinct ERIC-2 profiles were encountered. Eleven clonal groups, represented by multiple isolates (2 to 11) from the same sequence type (ST) or sequence type complex, were identified. These clonal groups accounted for 54 (49%) isolates overall. Membership in one of these clonal groups was more frequent among B2 isolates than non-B2 isolates (67% versus 32%, P < 0.001). The most frequent sequence types were ST95 (n = 13) and ST73 (n = 8), followed by the ST14 and ST10 complexes (n = 7). ST131 and ST69 were represented by three isolates each. Clonal group-associated isolates exhibited a greater prevalence of 11 virulence genes, including pap elements, than the other isolates. However, no association between clonal groups and host factors, type of infection, or mortality was observed. In conclusion, E. coli isolates causing spontaneous bacterial peritonitis and bacteremia in cirrhotic patients are genetically diverse. However, approximately half of the isolates belong to familiar clonal groups and exhibit extensive virulence profiles that may be associated with greater invasive potential.

Early-onset pneumonia after liver transplantation: microbiological findings and therapeutic consequences.

Early-onset hospital-acquired pneumonia (E-HAP) is one of the leading causes of sepsis and mortality after liver transplantation (LT). The appropriate antimicrobial therapy is crucially important for surviving sepsis in this context. The aim of this study was to analyze microbiological findings, associated factors, and optimal antibiotic regimens for E-HAP after LT. Patients demonstrating E-HAP in a single-center cohort of 148 LT recipients were prospectively detected. The diagnosis of pneumonia relied on a combination of supportive clinical findings and a positive culture of a lower respiratory tract sample. E-HAP was considered present if pneumonia occurred within 6 days of intensive care unit (ICU) admission after LT. Twenty-three patients (15.5%) developed E-HAP, which were caused by 36 pathogens (61.1% were gram-negative bacilli, and 33.3% were classified as hospital-acquired). For patients who developed E-HAP, the duration of mechanical ventilation and the ICU stay were significantly longer. Despite a trend toward higher mortality at any time in the E-HAP group, there was no significant difference in mortality between patients with E-HAP and patients without E-HAP. Lactatemia, vasopressor requirements, Simplified Acute Physiology Score II (SAPS II) score on ICU admission, and mechanical ventilation lasting more than 48 hours after LT were associated with E-HAP. Combinations of broad-spectrum ß-lactams and aminoglycosides were active against more than 91% of the encountered pathogens. However, antibiotic de-escalation was possible in more than one-third of cases after identification of the pathogens. In conclusion, E-HAP after LT is a severe condition that appears to be influenced by physiological derangements induced by the surgery, such as lactatemia, vasopressor requirements, and mechanical ventilation requirements, as well as the postoperative SAPS II score. At the time of treatment initiation, an antimicrobial regimen usually proposed for late-onset pneumonia should be followed.

Microbial epidemiology and outcome of bloodstream infections in liver transplant recipients: an analysis of 259 episodes.

Bloodstream infections (BSIs) are a major cause of mortality in liver transplant recipients. The incidence, microbiology, and outcome of BSIs in the first year after liver transplantation were analyzed in 704 patients who underwent transplantation at a single center between 1997 and 2007. BSIs occurred in 205 (29.1%) of the 704 patients. Overall, 259 episodes were documented, and they resulted in an incidence rate of 36.8%. Of these episodes, 39.4%, 27.8%, 17%, and 15.8% occurred in the very early period (< or = 10 days after liver transplantation), the early period (days 11-30), the intermediate period (days 31-90), and the late period (days 91-365), respectively. The most frequent pathogens were Enterobacteriaceae members (41%), Staphylococcus aureus (19.8%), enterococci (13.1%), Pseudomonas aeruginosa (8.8%), and yeasts (7.1%). The median time of onset ranged from 7 days for methicillin-resistant S. aureus to 25 days for Enterobacteriaceae. Mortality at 15 days after BSIs was 16.2%. Kaplan-Meier survival curves showed that patients with BSIs had a significantly higher 1-year mortality rate than those without BSIs (28.3% versus 16.6%, P < 0.001 with the log-rank test). When the time of BSI onset was considered, 1-year mortality was significantly associated with very early and early episodes (P < 0.001) but not with intermediate and late episodes (P = 0.47). In conclusion, BSIs are frequent and early complications after liver transplantation and are mostly caused by gram-negative bacilli. A BSI in the first posttransplant month is a significant predictor of 1-year survival.