Cryptogenic pyogenic liver abscess caused by Fusobacterium necrophorum in an immunocompetent patient.

Pyogenic liver abscesses are potentially fatal conditions that require prompt treatment with drainage and appropriate antimicrobial therapy. Fusobacterium necrophorum is a gram-negative rod that is found in the oral cavity, gastrointestinal tract and female genital tract. It is an extremely rare cause of liver abscess, particularly in the absence of risk factors or exposures. We describe an unusual case of a cryptogenic F. necrophorum hepatic abscess without a clear source despite extensive investigation in a young, immunocompetent patient without known risk factors or exposures for such an infection.

Incidence of Colorectal Cancer in Patients Diagnosed With Pyogenic Liver Abscess.

Importance: Colorectal cancer (CRC) can compromise the mucosal barrier and subsequently allow a route for bacterial invasion into the portal system or systemic circulation. Despite preliminary data suggesting that patients who experienced pyogenic liver abscess (PLA) have higher CRC incidence rates, data from outside the Southeast Asian population are sparse. Objective: To investigate whether there is an association between PLA and the subsequent incidence of diagnosed CRC using the Veterans Health Administration (VHA) cohort. Design, Setting, and Participants: A patient-level matched retrospective cohort study was conducted at 127 VHA hospitals across the US from January 1, 2003, to December 31, 2020. Patients were followed up to 10 years from PLA diagnosis. Data analysis was performed from April 14, 2002, to October 31, 2023. All patients who were admitted to VHA hospitals with a diagnosis of PLA were included. For each patient with PLA, up to 3 controls without diagnosis of PLA, matching age, sex, and health care facility, were selected. Exposure: Pyogenic liver abscess. Main Outcomes and Measures: The primary outcome was CRC diagnosis during the follow-up period. A multivariable Fine-Gray subdistribution regression model with time-dependent coefficient was used to estimate the time-varying hazard ratio (HR) of CRC incidence while accounting for mortality as a competing event. Results: A total of 8286 patients with PLA (male, 96.5%; mean [SD] age, 65.8 [11.9] years) and 23 201 patient-level matched controls (male, 96.3%; mean age, 65.3 [11.7] years) were included. A diagnosis of CRC was found in a significantly higher proportion of patients with PLA compared with controls (1.9% [159 of 8286] vs 0.8% [196 of 23 201]; P < .001). The incidence of CRC was significantly higher among patients with PLA during the first 3 years from PLA diagnosis (HR, 3.64; 95% CI, 2.70-4.91 at 0.5 years; HR, 2.51; 95% CI, 1.93-3.26 at 1 year; HR, 1.74; 95% CI, 1.33-2.28 at 2 years; and HR, 1.41; 95% CI, 1.05-1.89 at 3 years), but not significant after 3 years. This association was not observed among patients whose PLA was likely secondary to cholangitis or cholecystitis (HR, 1.78; 95% CI, 0.89-3.56 at 0.5 years). Conclusions and Relevance: In this patient-level matched retrospective cohort study, a significantly higher incidence of CRC was observed up to 3 years from PLA diagnosis. The findings suggest that offering CRC screening for patients with cryptogenic PLA may be useful, especially patients who have not been screened according to guidelines.

Pyogenic liver abscess caused by extended-spectrum ß-lactamase-producing hypervirulent Klebsiella pneumoniae diagnosed by third-generation sequencing: a case report and literature review.

We report a case of a woman with diabetes mellitus and choledocholithiasis who had a low fever with chills and severe weakness for 7 days. The patient's abdominal tenderness was positive. Computed tomography and magnetic resonance imaging showed a giant abscess in the liver. The production of extended-spectrum ß-lactamases by hypervirulent Klebsiella pneumoniae was found in the purulent fluid of the liver by nanopore-based metagenomic third-generation sequencing combined with an antibiotic susceptibility test. The patient recovered after intravenous antibiotic therapy and percutaneous drainage. Patients with a history of diabetes mellitus and choledocholithiasis should be aware of the possibility of pyogenic liver abscesses caused by hypervirulent Klebsiella pneumoniae. To rapidly control the development of this disease, nanopore-based metagenomic third-generation sequencing plays an important role not only in rapidly identifying pathogens, but also in guiding the use of antibiotics.

Development and validation of a nomogram for predicting sepsis in patients with pyogenic liver abscess.

Pyogenic liver abscess (PLA) is a severe condition that significantly increases the risk of sepsis. However, there is a notable dearth of research regarding the prediction of sepsis in PLA patients. The objective of this study was to develop and validate a prognostic nomogram for predicting sepsis in PLA patients. A total of 206 PLA patients were enrolled in our study, out of which 60 individuals (29.1%) met the Sepsis-3 criteria. Independent risk factors for sepsis were identified through univariate and multivariate logistic regression analyses. Subsequently, a nomogram was developed based on age, positive blood culture, procalcitonin, alanine aminotransferase, blood urea nitrogen, and D-dimer. The nomogram demonstrated excellent calibration and discrimination, as evidenced by the area under the receiver operating characteristic curve (AUC) values of 0.946 (95% confidence interval [CI], 0.912-0.979) and 0.980 (95%CI 0.951-1.000) in the derivation and validation cohorts, respectively. Furthermore, decision-curve analysis confirmed the clinical utility of the nomogram. This study provides valuable insights for the prevention of sepsis in PLA patients and underscores the potential application of the prognostic nomogram in clinical practice.

Pyogenic liver abscess complicated with endogenous endophthalmitis caused by Klebsiella pneumoniae: A case report and Literature Review.

OBJECTIVE: Pyogenic liver abscess (PLA) is a common surgical infectious disease caused by various pathogens. Klebsiella pneumoniae is a relatively recent cause, often affecting patients with low immunity. Endogenous endophthalmitis (EE), a rare and serious complication of PLA, may appear with eye symptoms before PLA. By reviewing a case of Klebsiella pneumoniae-induced PLA complicated with EE, we want to summarize the information about the characteristics, causes, and complications of PLA based on the literature review. METHODS: This case report describes a 37-year-old male who had fever high to 39°C for 10 days experienced blurred vision followed by nonlight perception vision. He reported a history of diabetes irregularly taking oral medications and insulin therapy. Imaging examination found a large low-density area in the right lobe of the liver with an unclear border and vague surrounding fat gap. The blood culture was not positive. The culture of the drainage fluid from the liver puncture showed Klebsiella pneumonia. Blood and liver puncture drainage fluid were sent for microbial high-throughput gene detection with next-generation sequencing technology (NGS), which confirmed the diagnosis of Klebsiella pneumoniae-induced PLA complicated with EE. RESULTS: The patient's surgical incision had healed well at discharge, and he could feel light at his left eye. But the patient was lost to follow-up since the third month after discharge. CONCLUSION: By reviewing this case and summarize the information about the characteristics, causes, and complications of PLA based on the literature review, we concluded that it is necessary to promptly perform liver puncture drainage and empirically use antibiotics for patients with PLA, especially those with poor glycemic control, to avoid serious complications such as EE.

Clinical manifestations, diagnosis, treatment, and outcome of pyogenic liver abscess: a retrospective study.

OBJECTIVE: The incidence of pyogenic liver abscess (PLA) continues to rise, yet atypical clinical symptoms result in considerable incidence of misdiagnosis. This study was conducted to identify potential warning indicators and summarize efficacious diagnostic and therapeutic approaches for potential clinical guidelines. METHODS: Hospitalized patients aged ≥18 years and diagnosed with PLA were included in this retrospective study. Data were collected from participant's clinical records. Patients were grouped according to type 2 diabetes mellitus status and ultrasound-guided percutaneous drainage (USPD). Between-group differences were analysed with Student's t-test. RESULTS: A total of 104 hospitalized patients were included, 33 of whom (31.73%) had type 2 diabetes. Procalcitonin levels were raised in all patients, suggesting potential effectiveness and sensitivity as a warning marker for PLA. Contrast-enhanced computed tomography was the most frequently used method (63.46% of cases) for diagnosing PLA. Klebsiella pneumoniae was the main pathogen found in patients with PLA in southeast China (isolated in 92.86% [26/28] of positive blood cultures and 90.70% [39/43] of positive abscess fluid cultures). Duration of hospital stay was shorter in patients who received USPD versus those who did not (17.91 ± 6.84 days versus 21.47 ± 9.82 days). CONCLUSION: Types of PLA-susceptible patients, infection markers, highly sensitive imaging techniques and clinical treatment options were identified. These results may help with early accurate diagnosis of patients with PLA, avoiding treatment delay.

Cryptogenic Hypervirulent Klebsiella pneumoniae Pyogenic Liver Abscess: A Case Report.

BACKGROUND Klebsiella pneumoniae is a gram-negative organism known to cause pyogenic liver abscesses. It is most often caused by one of the hypervirulent strains, which are capable of causing metastatic infection. This occurs most commonly in Asia in patients without hepatobiliary disease; however, it is becoming increasingly recognized in North America. CASE REPORT We report a previously healthy man in his 50s who presented to hospital with 3 weeks of fever, chills, and mild abdominal pain following a minor motor vehicle collision. Ultrasound and computed tomography of his abdomen revealed a large multi-loculated liver abscess. This was drained percutaneously and grew a hypervirulent strain of Klebsiella pneumoniae known to cause metastatic infection. His blood cultures were negative. In addition to percutaneous drainage, he was treated with 8 weeks of antimicrobial therapy. Fortunately, he did not develop evidence of metastatic infection despite the hypervirulent strain. Etiology of the abscess was not clearly identified; however, it was speculated that the motor vehicle collision could have led to its development through gut translocation. CONCLUSIONS Presentation of Klebsiella pneumoniae liver abscesses is often nonspecific, and clinicians must have a high index of suspicion in order to ensure rapid diagnosis and treatment. Delay in diagnosis is associated with increased morbidity and mortality, and thus it is an important entity for clinicians to be aware of, especially as it becomes more prevalent in North American populations. Additionally, it is important that physicians are aware of the hypervirulent strains and screen patients clinically for evidence of metastatic infection.

Management of Pyogenic Liver Abscesses: Contemporary Strategies and Challenges.

Pyogenic liver abscesses (PLAs) are a suppurative infection of the hepatic parenchyma responsible for significant morbidity and mortality. PLAs are categorized into a variety of mechanisms: (1) via the portal vein, (2) through the biliary tract, (3) via the hepatic artery, (4) from trauma, (5) contiguously via direct extension, and (6) cryptogenically. The pathogenesis of PLA, which informs treatment, can often be discerned based on host factors, clinical presentation, and causative microorganisms. The Streptococcus anginosus group, hypervirulent Klebsiella pneumoniae , and multidrug-resistant gram-negative pathogens have emerged as microbiologically challenging organisms to treat. The identification of hypervirulent K. pneumoniae should prompt for assessment for metastatic spread and consideration of prolonged antimicrobial treatment. Abdominal imaging is indispensable in characterizing PLAs and facilitating source control interventions. Source control remains the most critical aspect of PLA management, followed by antimicrobial therapy. Empiric antibiotics for PLAs are informed by the suspected etiology of PLA formation. Duration of antimicrobial therapy is individualized and dependent on multiple components, including the success of achieving source control, host factors, mechanism of PLA development, and the illness course of the individual-factoring in clinical, biochemical, and radiographic parameters.

Giant Klebsiella pneumoniae pyogenic liver abscess in the left liver lobe presenting with dyspepsia and vaginal discharge.

Pyogenic liver abscess (PLA) commonly occurs in the right liver lobe, causing the typical symptoms of fever and right upper quadrant pain. Less than one-third of cases occur in the left lobe. We describe an unusual presentation of a giant left-sided PLA that was compressing the stomach and surrounding venous vasculature, causing the respective symptoms of gastro-oesophageal reflux and vaginal discharge from secondary pelvic congestion syndrome. CT revealed a solitary 14 cm×10 cm×10 cm multiloculated lesion, replacing most of the left liver lobe. It was successfully treated with intravenous antibiotics and percutaneous drainage, resulting in complete resolution at 1-year follow-up. This case explores the predisposing risk factor of diabetes in PLA and its association with Klebsiella pneumoniae, which was the offending pathogen in our patient. We also discuss the phenomenon of secondary pelvic venous congestion syndrome and compare similar cases of left-sided PLA, highlighting the different modes of presentation and treatment options.

[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.

Endogenous Endophthalmitis From a Klebsiella pneumoniae Liver Abscess: The Incidence, Risk Factors, and Utility of Imaging.

PURPOSE: We investigated the rate of ophthalmologic examinations to detect endogenous endophthalmitis in patients with pyogenic liver abscesses (PLAs) and the incidence and risk factors of endophthalmitis from a PLA caused by Klebsiella pneumoniae (PLA-K). DESIGN: Retrospective case series. METHODS: A total of 536 patients admitted to a university hospital in Korea to treat PLAs during 2012-2022 were included. The proportion of patients who were referred for ophthalmologic examinations was investigated and the incidence of endophthalmitis in 248 patients with PLA-K was calculated. Univariate and multivariate logistic regression analyses were performed to define risk factors including demographic characteristics, underlying diseases, radiologic findings, and systemic conditions. RESULTS: A comprehensive ophthalmologic examination was performed in 73.7% of all patients with PLAs, and the incidence of endophthalmitis from a PLA-K was 7.3%. A liver abscess >5 cm increased the incidence of endogenous endophthalmitis 4-fold compared with smaller abscesses (odds ratio [OR] = 4.01 [95% confidence interval {CI}, 1.02-15.78], P = .047) and portal or hepatic vein thrombophlebitis increased the incidence approximately 4-fold (OR = 4.04 [95% CI, 1.10-14.83], P = .036). Acute cholangitis was approximately 8-fold (OR = 8.33 [95% CI, 1.25-55.71], P = .029), and disseminated intravascular coagulation was approximately 6-fold (OR = 5.76 [95% CI, 1.22-27.21], P = .027) more related to prevalence of endophthalmitis. Other extrahepatic infections increased the incidence approximately 43-fold (OR = 43.06 [95% CI, 10.14-182.90], P < .001). CONCLUSIONS: Clinicians should consider the risk of endogenous endophthalmitis when PLA-K patients have large liver abscesses (>5 cm), acute cholangitis, portal or hepatic vein thrombophlebitis, disseminated intravascular coagulation, or other extrahepatic infections.

Increasing incidence of pyogenic liver abscess in Southern Sweden: a population-based study from 2011 to 2020.

BACKGROUND: Pyogenic liver abscess (PLA) is a rare but potentially life-threatening disease, and estimates suggest a gradual increase in the incidence during the last decades. The primary aim of this study was to report the incidence, trend and aetiology of PLA during a decade in Southern Sweden. METHODS: This was a population-based observational cohort study between 2011 and 2020 in Skåne, Southern Sweden. Data were retrieved from the Swedish National Board of Health and Welfare for all individuals diagnosed with liver abscess (K750) according to ICD-10 (International Statistical Classification of Diseases, 10th revision). RESULTS: A total of 456 episodes of PLA occurred in 364 patients during the study period. The median age of the first PLA episode was 71 years (range 3-97) and 57% (n = 206) were men. The mean incidence of all patients was 3.4/100,000 person-years (range 1.8-5.2). The incidence increased almost three times, from 1.8/100,000 person-years in 2011 to 5.2/100,000 person-years in 2020. Streptococcus species, Escherichia coli and Klebsiella species accounted for the vast majority of both mono- and polymicrobial findings in both blood and local abscess cultures. 16s rDNA added information about aetiology in 37% of episodes. CONCLUSION: The incidence of PLA increased during the study period, and Streptococcus spp., Klebsiella spp. and E. coli dominated both blood and local cultures. Despite antimicrobial therapy, pathogens could be found in local abscess cultures several weeks into treatment. Increased use of 16s rDNA in the management of PLA could be beneficial.

Risk factors indicating the need for surgical therapy in patients with pyogenic liver abscesses.

BACKGROUND: Percutaneous drainage (PD) and antibiotics are the therapy of choice (non-surgical therapy [non-ST]) for pyogenic liver abscesses (PLA), reserving surgical therapy (ST) for PD failure. The aim of this retrospective study was to identify risk factors that indicate the need for ST. METHODS: We reviewed the medical charts of all of our institution's adult patients with a diagnosis of PLA between January 2000 and November 2020. A series of 296 patients with PLA was divided into two groups according to the therapy used: ST (n = 41 patients) and non-ST (n = 255). A comparison between groups was performed. RESULTS: The overall median age was 68 years. Demographics, clinical history, underlying pathology, and laboratory variables were similar in both groups, except for the duration of PLA symptoms < 10 days and leukocyte count which were significantly higher in the ST group. The in-hospital mortality rate in the ST group was 12.2% vs. 10.2% in the non-ST group (p = 0.783), with biliary sepsis and tumor-related abscesses as the most frequent causes of death. Hospital stay and PLA recurrence were statistically insignificant between groups. One-year actuarial patient survival was 80.2% in the ST group vs. 84.6% in the non-ST (p = 0.625) group. The presence of underlying biliary disease, intra-abdominal tumor, and duration of symptoms for less than 10 days on presentation comprised the risk factors that indicated the need to perform ST. CONCLUSIONS: There is little evidence regarding the decision to perform ST, but according to this study, the presence of underlying biliary disease or an intra-abdominal tumor and the duration of PLA symptoms < 10 days upon presentation are risk factors that should sway the surgeons to perform ST instead of PD.

Pyogenic liver abscess after open hemorrhoidectomy.

BACKGROUND: Surgical excision of hemorrhoids remains the gold standard for patients who have grade III or IV hemorrhoids. The complication rate is low and success rate is high. In this case, we describe a 44-year-old male with septic shock and small liver abscesses as a rare complication after Milligan-Morgan hemorrhoidectomy. METHODS: In this case report, we describe the case of a patient with septic shock and small liver abscesses as a rare complication after Milligan-Morgan hemorrhoidectomy. A search in the PubMed database showed only three publications describing patients with liver abscesses after hemorrhoidectomy and some more cases after rubber band ligation. RESULTS: The patient was admitted at the intensive care unit and received intravenous antibiotics. He could leave the hospital in good condition after 17 days. He received antibiotics for six weeks in total. CONCLUSION: Pyogenic liver abscess after open hemorrhoidectomy is a rare complication after Milligan-Morgan hemorrhoidectomy and rubber band ligation. Pyogenic liver abscesses can be treated with antibiotics, sometimes associated with percutaneous drainage or surgeryIn patients with predisposing factors prophylactic use of antibiotics could be considered on a case-by-case basis.

Predictive and prognostic factors associated with unliquefied pyogenic liver abscesses.

INTRODUCTION: Poor liquefaction of pyogenic liver abscesses, which makes drainage impossible at the time of diagnosis, is not infrequent. The impact of poor liquefaction and subsequent drainage failure on clinical outcomes is unknown. METHODS: We conducted a retrospective study with all patients diagnosed with liver abscesses from July 2017 through June 2020. Late drainage (LD) was defined as drainage performed ≥48 h after diagnosis due to poor liquefaction. Logistic regression was performed to identify the factors associated with late or non-drainage (LD/ND). The Cox proportional hazard model was used to identify the variables related to abscess recurrence by 90 days after diagnosis. RESULTS: A total of 153 patients were included. Thirty (19.6%) patients underwent LD and 54 (35.3%) did not undergo drainage. Other than non-cystic appearance, LD/ND was associated with smaller size (adjusted odds ratio [aOR] 0.85, 95% confidence interval [CI] 0.73-0.98, p = 0.031) and culture-negativity (aOR 2.69, 95% CI 1.14-6.67, p = 0.027). Current hepatopancreaticobiliary malignancy was the only significant predictor of 90-day recurrence. Neither LD/ND (OR, 0.56; 95% CI, 0.13-2.41; p = 0.426) nor LD (OR, 1.26; 95% CI, 0.23-5.55; p = 0.719) was associated with recurrence by 90 days. The incidence of late complications was reduced by drainage, without a reduction in the duration of hospitalization. CONCLUSION: Several clinical features were associated with undrainable liver abscesses. Neither LD/ND nor ND had an adverse impact on clinical outcomes.

Raptured gas forming pyogenic liver abscess with a biliary fistula in Botswana: a case report.

We report a case of gas-forming pyogenic liver abscess (GFPLA) with a ruptured abscess and biliary fistula presenting with peritonitis. The patient had poorly controlled diabetes mellitus and was extremely ill at presentation. The diagnosis was delayed until the abscess ruptured, owing to nonspecific abdominal symptoms at the initial presentation and delayed follow-up radiological investigations. The patient had a high-output biliary fistula post-operatively, which was managed with endoscopic retrograde cholangiopancreatography (ERCP) and stenting with fistula drainage reduction within four weeks. This case highlights the need for follow-up radiological investigations and prompt intervention in patients with diabetes mellitus presenting with fever and vague abdominal pain.

Pyogenic Liver Abscess: Contemporary Trends in a Tertiary Institute.

Background: Pyogenic liver abscess (PLA) is an uncommon but potentially life-threatening condition. In recent years, advances in diagnostics and management have led to early diagnosis and treatment and decreased mortality. We present recent data from a large series of patients with PLA and examine the trends in the management of PLA over a period of 50 years. Methods: The medical records of all patients admitted to the Shaare Zedek Medical Center, Israel, between January 2011 and December 2021 with a primary or secondary diagnosis of PLA were reviewed retrospectively. Results: : Ninety-five patients with PLA were identified. Thirty-eight (40%) were female. The median patient age was 66 years (range 18-93). The diagnosis of PLA in all patients was confirmed with abdominal computed tomography (CT). In twenty patients (21.1%), PLA was not diagnosed by the initial abdominal US. Most abscesses were right-sided. Biliary tract origin was the most common underlying cause of PLA (n = 57, 60%), followed by cryptogenic etiology (n = 28, 30%). Escherichia coli, Klebsiella pneumoniae, and Streptococcus species were most commonly identified. The most common primary treatment modality was percutaneous drainage (PD), which was performed in 81 patients (85.3%). Fourteen patients (14.7%) were treated medically without intervention, and two patients (2.1%) were treated surgically following a failure of PD. Four patients died as a direct result of PLA. Conclusions: Patients diagnosed with PLA are older, the male predominance is less pronounced, and the offending pathogens are likely to originate from the biliary tract. This study questions the utility of abdominal US as the initial diagnostic imaging in patients with suspected PLA (versus CT) and demonstrates improved outcomes for patients with PLA over the years.

Klebsiella pneumoniae K2 producer of pyogenic liver abscess associated with biliary communication.

INTRODUCTION: Hypervirulent strains of Klebsiella pneumoniae have gained clinical and epidemiological interest because of their capacity to cause severe and life-threatening infections. METHODOLOGY: We report a case involving infection with a hypervirulent K. pneumoniae K2 strain that caused liver abscess in a young woman with type 1 diabetes in Mexico. RESULTS: The infection was found to be associated with biliary tract communication. The virulence factors and capsular serotypes were identified by polymerase chain reaction analysis. After guided drainage and directed antibiotic treatment, the infection resolved and the patient recovered. Colonization of the gastrointestinal tract by hypervirulent K. pneumoniae strains, together with the presence of comorbidity, such as diabetes are important factors that contribute to the development of liver abscess. CONCLUSIONS: The identification of virulent clones is important to understand the pathogenicity and improve control of infections in the patients.