Clinical and microbiological characteristics of pyogenic liver abscess in a tertiary hospital in East China

Prognostic risk factors for pyogenic liver abscess caused by Klebsiella pneumoniae

BACKGROUND

Pyogenic liver abscess (PLA) caused by Klebsiella pneumoniae can vary in severity, and several risk factors for the development of organ dysfunction in PLA have been implicated. However, few studies to date have explored the most common risk factors for clinical severity.

METHODS

We conducted a study on patients with PLA caused by Klebsiella pneumoniae between February 2013 and December 2022.Using logistic regression analysis, we sought to identify factors associated with positive blood culture, septic shock, and intensive care unit (ICU) admission.

RESULTS

After included 200 patients, we found that an elevated procalcitonin (PCT) level (p = 0.03), higher glucose level (p = 0.03), and lower total cholesterol (TC) level (p = 0.01) were associated with a higher likelihood of positive blood bacteriological culture. Additionally, an increased PCT level (p = 0.02) and lower TC level (p < 0.01) were associated with an elevated risk of septic shock. Furthermore, a higher PCT level (p < 0.01) was associated with a higher probability of ICU admission.

CONCLUSION

In patients with PLA caused by Klebsiella pneumoniae, the PCT, glucose, and TC levels were found to be associated with positive blood culture, septic shock, and ICU admission.

Endoscopic Features of Post-COVID-19 Cholangiopathy and Its Management Using ERCP

INTRODUCTION

Despite growing awareness of post-coronavirus disease 2019 (COVID-19) cholangiopathy as one of the most serious long-term gastrointestinal consequences of COVID-19, the endoscopic features of this disease are still poorly characterized. This study aimed to more precisely define its endoscopic features and to outline the role of endoscopic retrograde cholangiopancreatography (ERCP) in the management of this entity.

METHODS

In this observational study, 46 patients with confirmed post-COVID-19 cholangiopathy were included.

RESULTS

Based on the endoscopic features observed in 141 ERCP procedures, post-COVID-19 cholangiopathy can be classified as a variant of secondary sclerosing cholangitis in critically ill patients. It appeared early in the course of intensive care treatment of patients with COVID-19 (cholestasis onset 4.5 days after intubation, median). This form of cholangiopathy was more destructive than stricturing in nature and caused irreversible damage to the bile ducts. A centripetal pattern of intrahepatic bile duct destruction, the phenomenon of vanishing bile ducts, the absence of extrahepatic involvement, and the presence of intraductal biliary casts (85% of patients) were typical cholangiographic features of post-COVID-19 cholangiopathy. This cholangiopathy was often complicated by small peribiliary liver abscesses with isolation of Enterococcus faecium and Candida spp. in bile culture. The prognosis was dismal, with a 1-year liver transplantation-free survival rate of 44%. In particular, patients with peribiliary liver abscesses or destruction of the central bile ducts tended to have a poor prognosis (n.s.). As shown by multivariate analysis, bilirubin levels (on intensive care unit day 25-36) negatively correlated with liver transplantation-free survival (hazard ratio 1.08, P < 0.001). Interventional endoscopy with cast removal had a positive effect on cholestasis parameters (gamma-glutamyl transpeptidase, alkaline phosphatase, and bilirubin); approximately 60% of all individual values decreased.

DISCUSSION

Gastrointestinal endoscopy makes an important contribution to the management of post-COVID-19 cholangiopathy. ERCP is not only of great diagnostic and prognostic value but also has therapeutic value and therefore remains indispensable.

Pasteurella multocida bacteraemia with liver abscess

A previously healthy woman in her mid-70s presented with right upper quadrant abdominal pain, fever, intermittent chills and malaise for 1 week. She was clinically septic with raised inflammatory markers. Her blood culture revealed Pasteurella multocida, which was susceptible to penicillin and amoxicillin-clavulanic acid. CT of liver revealed an abscess of 8.0×7.9×8.5 cm at the left lobe of the liver. However, the abscess was not amenable for surgical or radiological drainage. She was a farmer and had close contact with her pet cats. She was occasionally scratched by her cats when caring for them. The liver abscess resolved completely without drainage after prolonged antimicrobial therapy of 109 days. She commenced on 63 days of intravenous antimicrobials and 46 days of oral amoxicillin-clavulanic acid. This case illustrated P. multocida bacteraemia with a large liver abscess in an immunocompetent adult after non-bite exposure.

Bacteriophages and Their Host Range in Multidrug-Resistant Bacterial Disease Treatment

The rapid emergence of multidrug-resistant (MDR) bacteria in recent times has prompted the search for new and more potent antibiotics. Bacteriophages (commonly known as phages) are viruses that target and infect their bacterial hosts. As such, they are also a potential alternative to antibiotics. These phages can be broadly categorized into monovalent (with a narrow host range spectrum and specific to a single bacterial genus) and polyvalent (with a broad host range and specific to more than two genera). However, there is still much ambiguity in the use of these terms, with researchers often describing their phages differently. There is considerable research on the use of both narrow- and broad-host range phages in the treatment of infections and diseases caused by MDR bacteria, including tuberculosis, cystic fibrosis, and carbapenem-resistant Enterobacterales (CRE) infectious diseases. From this, it is clear that the host range of these phages plays a vital role in determining the effectiveness of any phage therapy, and this factor is usually analyzed based on the advantages and limitations of different host ranges. There have also been efforts to expand phage host ranges via phage cocktail development, phage engineering and combination therapies, in line with current technological advancements. This literature review aims to provide a more in-depth understanding of the role of phage host ranges in the effectiveness of treating MDR-bacterial diseases, by exploring the following: phage biology, the importance of phages in MDR bacteria diseases treatment, the importance of phage host range and its advantages and limitations, current findings and recent developments, and finally, possible future directions for wide host range phages.

The New Changes of Epidemiology, Etiology, and Clinical Characteristics of Pyogenic Liver Abscesses: A Retrospective Study in a Hospital in Northern China

Purpose

To investigate the epidemiology, etiology, and clinical characteristics of patients with pyogenic liver abscesses (PLA) and provide guidance for clinical treatments.

Patients and Methods

A retrospective study was performed on a cohort of 402 hospitalized patients diagnosed with PLAs at the Affiliated Hospital of Chengde Medical College between January 2016 and December 2021. Patient demographics, drug sensitivity profiles, and microbiological culture results of drainage and blood samples were thoroughly analyzed to identify significant patterns or trends. Furthermore, clinical characteristics and treatments for patients with PLA were comprehensively assessed.

Results

Patients aged 50-69 years had the highest incidence of PLA, accounting for 59.9% of all cases, and 91.5% of them had a fever. Bacterial culture analysis of the 200 patients revealed that Klebsiella pneumoniae (K. pneumoniae) was the most predominant pathogen, detected in 70.5% of cases, exhibiting an upward trend. Escherichia coli (E. coli) was the second most frequently detected pathogen, identified in 14.5% of cases, showing a downward trend. Coexisting diabetes mellitus (DM) was found to be the most common comorbidity for PLA, occurring in most patients with the condition. Patients with a history of abdominal surgery and malignancy had an increased risk for PLA, while those with gallstones had a decreased risk. Drainage combined with antibiotic therapy was identified as the primary treatment of PLA. In addition, multivariate analysis demonstrated that coexisting DM and the presence of gas in the abscess cavity were independent risk factors for septic shock in patients with PLA.

Conclusion

This study reveals a shift in the proportions of pathogens and risk factors in patients with PLA, underscoring the necessity for improved diagnostic and therapeutic strategies.

Study on Virulence Genes, Drug Resistance and Molecular Epidemiology of Klebsiella pneumoniae with High Virulence in Inner Mongolia, China

Objective

The purpose of this study was to analyse the clinical, microbiological and molecular epidemiological characteristics of patients with pyogenic liver abscess (PLA) caused by Klebsiella pneumoniae (KPN) in Inner Mongolia, China.

Methods

The KPN isolates from 78 KPN-PLA cases admitted to a tertiary teaching hospital in Baotou, Inner Mongolia, from 2016 to 2019 were studied systematically and described comprehensively. The virulence factors, drug resistance and sequence types of KPN in different samples were identified by a wire-drawing test, polymerase chain reaction, a drug susceptibility test and multi-site sequence typing.

Results

There were more male than female KPN-PLA patients (P<0.05). The mortality rate was 2.5%, and KPN-PLA was significantly associated with diabetes mellitus (P<0.05). Most of the KPN isolates in the puncture fluid of patients with KPN-PLA were hypervirulent KPN (HvKP). The positive rate of the KPN-PLA specimens was higher than that of the blood and urine specimens. The KPN isolates of the urine specimens had higher drug resistance than the other two (P<0.05). The hypermucoviscous KPN, aerobic actin (aero) (+), K1 and K2 serotypes accounted for 80.8%, 89.7%, 56.4% and 26.9%, respectively. In addition to ironB (3.8%), the detection rates of virulence factors rmpA, irp2, entB, iucD, aero, wcaG, iutA, kfu, ybtA, iron, fimH and mrkD were higher (69.2%-100.0%). The positive rate of KPN isolates of the KPN-PLA puncture fluid was higher than that of the blood and urine samples (P<0.05). In addition, ST23 was found to be the dominant ST (32.1%) of KPN-PLA in the Baotou region.

Conclusion

In the KPN-PLA specimens, the KPN isolates were more virulent than those in the blood and urine specimens, and a carbapenem-resistant HvKP strain emerged. This research will help improve the understanding of HvKP and provide useful suggestions for KPN-PLA treatments.

Demographics and Clinical Outcomes of Culture-Positive versus Culture-Negative Pyogenic Liver Abscess in an Asian Population

Objective

Despite its high case-fatality risk, pyogenic liver abscess (PLA) lacks clear management guidelines in patients with negative microbial cultures. Our aim was to evaluate differences in clinical characteristics between patients with culture-negative liver abscess (CNLA) and those with culture-positive liver abscess (CPLA), and identify differences in the main causative pathogen.

Methods

In this study, we retrospectively collected medical records of PLA patients admitted to a teaching hospital from January 2010 to December 2019.

Results

In total, 324 PLA patients were enrolled in this study. Of these, 202 (62.3%) cases were confirmed cultural positive, including 109 patients (54%) and 20 (9.9%) patients infected with Klebsiella pneumoniae (K. pneumoniae) and Escherichia coli (E.coli), respectively. Patients in the CPLA group were older (p=0.029) and had higher prevalence of abscesses larger than 5 cm in diameter (p = 0.003), gas-forming rate (p = 0.016), and percutaneous drainage (p < 0.001) compared with CNLA group. Patients with CPLA had significantly longer hospitalizations than those with CNLA (p = 0.010). Nevertheless, there was no significant difference in in-hospital mortality between the two groups (p = 0.415). Compared with patients with E. coli, those with K. pneumoniae had higher incidence of diabetes mellitus (p = 0.041), solitary abscess (p < 0.001), localization in the right hepatic lobe (p = 0.033), abscess size larger than 5 cm (p < 0.001) and percutaneous drainage (p = 0.002), but mortality was not significantly different (p = 1.000).

Conclusion

No significant difference in in-hospital mortality was found between patients with CNLA and those with CPLA group. However, clinical characteristics and management were different between the main causative pathogens, including K. pneumoniae and E. coli.

Genetic and Phenotypic Characterization of Multidrug-Resistant Klebsiella pneumoniae from Liver Abscess

Cooccurrence of multidrug resistant (MDR) and hypervirulence phenotypes in liver abscess-causing Klebsiella pneumoniae (LAKp) would pose a major threat to public health. However, relatively little information is available on the genomic and phenotypic characteristics of this pathogen. This study aimed to investigate the virulence and resistance phenotype and genotype of MDR LAKp strains from 2016 to 2020. We collected 18 MDR LAKp strains from 395 liver abscess samples and characterized these strains using antimicrobial susceptibility test, string test, mucoviscosity assay, biofilm formation assay, Galleria mellonella killing assay, and whole-genome sequencing. Besides, phylogenetic and comparative genomic analyses were performed on these MDR LAKp, along with 94 LAKp genomes from global sources. Most of these MDR LAKp strains exhibited resistance to cephalosporins, quinolones, and chloramphenicol. Virulence assays revealed that only half of MDR LAKp strains exhibited higher virulence than classical MDR strain K. pneumoniae MGH78578. Importantly, we identified three ST11 KL64 hypervirulence carbapenem-resistant strains carrying blaKPC-2 and one colistin-resistant strain carrying mcr-1. Phylogenetic analysis revealed that 112 LAKp genomes were divided into two clades, and most of MDR LAKp strains in this study belonged to clade 1 (83.33%, 15/18). We also detected the loss of mucoviscosity mediated by mutations and ISKpn14 insertion in rmpA, and the latter representing a novel mechanism by which bacteria regulate RmpA system. This study provides novel insights into MDR LAKp and highlights the necessity for measures to prevent further spread of such organisms in hospital settings and the community. IMPORTANCE Pyogenic liver abscess is a potentially life-threatening suppurative infection of hepatic parenchyma. K. pneumoniae has emerged as a predominant pathogen of pyogenic liver abscess. Liver abscess-causing K. pneumoniae is generally considered hypervirulent K. pneumoniae and is susceptible to most antibiotics. Recently, convergence of multidrug resistant and hypervirulence phenotypes in liver abscess-causing K. pneumoniae was emerging and poses a major threat to public health. However, relatively little information is available on liver abscess-causing multidrug-resistant hypervirulent K. pneumoniae. In this study, we characterized phenotype and genotype of virulence and resistance of 18 multidrug-resistant hypervirulent liver abscess-causing K. pneumoniae strains collected from 395 pyogenic liver abscess cases in a tertiary teaching hospital over a 5-year period to enable in-depth understanding of this pathogen.

Pyogenic liver abscess in non-liver cancer patients and liver cancer patients treated with TACE: Etiological characteristics, treatment, and outcome analysis

Clinical, laboratory, and microbiological features, clinical outcomes, and pyogenic liver abscess (PLA) prognosis evaluation in non-liver cancer (Non-LC) and liver cancer patients treated with transarterial chemoembolization (TACE, LC-TACE). Clinical data of 48 consecutive PLA patients from January 2016 to December 2020 were retrospectively analyzed. Mortality between two PLA patient groups were compared, and mortality risk factors were evaluated. A total of 48 PLA patients (31 males and 17 females) from January 2016 to December 2020 met the study's inclusion criteria. There were 32 and 16 patients in the Non-LC and LC-TACE groups, respectively. Positive pus culture rate in the Non-LC group was 87.5% and positive pus culture rate in LC-TACE group was 81.3%. In the Non-LC group, 28 patients improved after treatment, 1 patient did not improve, and 3 patients died during hospitalization, with a 9.4% mortality rate. In the LC-TACE group, nine patients improved after treatment, three patients did not improve, and four patients died during hospitalization, with a 25% mortality rate. The Non-LC group cure time was 37.4 ± 23.1 days, while the LC-TACE group was 91.5 ± 49.7 days. PLA of the Non-LC group and the LC-TACE group were different in terms of pathogenic bacteria and cure time, and so on. A more comprehensive treatment should be considered for PLA after TACE.

Epidemiology, Clinical Features, and Outcome of Liver Abscess: A Single-Center Experience

Introduction Liver abscesses are rare, but whenever they occur, it is predominantly among males over 60 years of age. The paradigm in the treatment has changed, and percutaneous drainage is now the initial treatment for drainage of the abscesses. Open surgery is reserved for patients with septated abscesses and those greater than 5 cm. Objective  To study the etiological, clinical, pathological, and demographic characteristics of individuals with liver abscesses and to evaluate the outcome associated with different treatment strategies. Methods This clinico-epidemiological study was carried out at a tertiary care hospital in Jodhpur. One hundred patients with liver abscesses were studied. Patients were assigned to three groups: Group 1 - medical management alone (in non-aspirable uncomplicated abscess), Group 2 - USG-guided needle aspiration or pigtail percutaneous catheter drainage plus medical management (in unruptured aspirable abscess), Group 3 - open surgical drainage plus medical management (In ruptured abscesses). Of the total patients, 36% were treated with medical therapy alone, 45% with USG-guided needle aspiration, 10% with USG-guided percutaneous catheter drainage, and 9% with open surgical drainage. Results In our study, fever and hepatomegaly were the commonest presentations, observed in 91% and 62% of cases, respectively. Escherichia coli (E.coli) was the predominant organism cultured in 28 (43.75%) patients followed by Klebsiella growing in 24 (37.50%) patients. The right lobe was affected more (83%) than the left lobe and in the majority (83%), a solitary abscess was present. The mean age of liver abscess presentation was 40.72 years, with a 5.67:1 male-to-female ratio. Alcohol consumption was reported by 33% of patients, the majority of whom were men. Serum bilirubin was elevated in 56% of liver abscess patients, while it was normal in 44%. The mean serum bilirubin was 2.08 mg/dl. The mean value in group 1, group 2, and group 3 was 1.44 mg/dl, 2.23 mg/dl, and 2.57 mg/dl, respectively. Liver abscesses were identified in 76% of patients with right lobes; 83% had solitary liver abscesses and 17% had numerous abscesses. Abscess culture showed E. coli in 21 (32.81%) and Klebsiella in 17 (26.56%) patients. Conclusion Right-sided solitary pyogenic liver abscess caused by E.coli is the most common liver abscess, with fever and hepatomegaly as the most common presentation. Non-aspirable liver abscesses, regardless of aetiology, can be successfully treated by medical therapy alone. Needle aspiration or catheter drainage is standard for liver abscesses. Thus, needle aspiration has replaced the surgical exploration of liver abscesses.

Demographics, Radiological Findings, and Clinical Outcomes of Klebsiella pneumonia vs. Non-Klebsiella pneumoniae Pyogenic Liver Abscess: A Systematic Review and Meta-Analysis with Trial Sequential Analysis

Pyogenic liver abscess (PLA) is a common cause of hepatobiliary sepsis. Klebsiella pneumoniae (KP) is the most common organism causing PLA. Evidence is scarce on the demographics, radiological findings, and outcomes of KPPLA versus non-KPPLA (N-KPPLA). PubMed, Embase, The Cochrane Library, and Scopus were systematically searched until 14 May 2022 for studies comparing KPPLA and N-KPPLA. Exclusion criteria were single-arm studies. Primary outcomes were mortality (30-day/in-hospital) and metastatic complications. There were 16 studies, including 5127 patients (KPPLA n = 3305, N-KPPLA n = 1822). Patients with KPPLA were younger (mean difference: −2.04 years, p = 0.02). History of hepatobiliary disease (Odds ratio (OR) 0.30, 95% CI: 0.20, 0.46) and malignancy (OR 0.26, 95% CI: 0.16, 0.42) were less common in KPPLA. KPPLA was associated with lower incidence of multiple abscesses (OR 0.52, 95% CI: 0.35, 0.76, p < 0.001) and bilobar abscesses (OR 0.60, 95% CI: 0.49, 0.74, p < 0.001). KPPLA has higher overall metastatic complications (KPPLA 9.7% vs. N-KPPLA 4.8%, OR 3.16, 95% CI: 2.00, 4.99, p < 0.001), but lower mortality (KPPLA 3.9% vs. N-KPPLA 7.6%, OR 0.51, 95% CI: 0.34, 0.78, p < 0.001). Trial sequential analysis showed conclusive evidence that KPPLA has lower mortality than N-KPPLA. In conclusion, KPPLA has lower mortality than N-KPPLA.

Pyogenic liver abscess-caused Klebsiella pneumoniae in a tertiary hospital in China in 2017: implication of hypervirulent carbapenem-resistant strains

Background

To investigate the epidemiology of Klebsiella pneumoniae (K. pneumoniae) inducing pyogenic liver abscess (PLA) in east China and the role of hypervirulent carbapenem-resistant K. pneumoniae (Hv-CRKP).

Methods

Forty-three K. pneumoniae strains were collected from 43 patients with PLA at Hangzhou, China in 2017. Antimicrobial susceptibility tests, string test, multilocus sequence typing, pulsed-field gel electrophoresis, mobile genetic elements typing, regular PCR and sequencing, and Galleria mellonella (G. mellonella) lethality test were used to elucidate the epidemiology. Clinical data were collected.

Results

K. pneumoniae strains with serotypes K1 and K2 accounted for 69.8%, which shared 46.5% and 23.3% respectively. K. pneumoniae strains with clonal group 23 were predominant with a rate of 34.9%. Such antimicrobials showed susceptible rates over 80.0%: cefuroxime, cefotaxime, gentamycin, ticarcillin/clavulanate, ceftazidime, cefoperazone/tazobactam, cefepime, aztreonam, imipenem, meropenem, amikacin, tobramycin, ciprofloxacin, levofloxacin, doxycycline, minocycline, tigecycline, chloramphenicol, and trimethoprim-sulfamethoxazole. PFGE dendrogram showed 29 clusters for the 43 K. pneumoniae strains. Three Hv-CRKP strains were confirmed by G. mellonella lethality test, showing a constituent ratio of 7.0% (3/43). Totally three deaths were found, presenting a rate of 7.0% (3/43). The three died patients were all infected with Hv-CRKP.

Conclusions

K1 and K2 are the leading serotypes of K. pneumoniae causing PLA, which show highly divergent genetic backgrounds. Aminoglycosides, Generation 2^nd to 4^th cephalosporins, β-lactamase/β-lactamase inhibitors, carbapenems, fluoroquinolones are empirical choices. Hv-CRKP may confer an urgent challenge in the future.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07648-0.

Clinical and Molecular Analysis of ST11-K47 Carbapenem-Resistant Hypervirulent Klebsiella pneumoniae: A Strain Causing Liver Abscess

Klebsiella pneumoniae has been the predominant pathogen of liver abscess, but ST11-K47 carbapenem-resistant hypervirulent Klebsiella pneumoniae (CR-hvKP) has rarely been studied as the causative organism. We identified an ST11-K47 CR-hvKP (HvKp-su1) from the drainage fluid of a liver abscess in a Chinese man who was diagnosed with liver abscess combined with diabetes, pneumonia, pleural infection, abdominal abscess, and splenic abscess. HvKp-su1 was non-hypermucoviscous and lacked the magA and rmpA genes and pLVPK plasmid but exhibited high virulence, with a high mortality rate (90%) to wax moth larvae (G. mellonella), similar to the hypervirulent Klebsiella pneumoniae ATCC43816 (91.67%). Whole-genome sequencing and bioinformatics analysis indicated that HvKp-su1 possesses a plasmid similar to a type of pLVPK-like plasmid (JX-CR-hvKP-2-P2), which is an uncommon plasmid in CR-hvKP. HvKp-su1 carried multiple resistance genes, including bla_KPC-2. bla_TEM-1, bla_SHV-55, and bla_CTX-M-65; hypervirulence genes such as aerobactin (iutA), salmochelin (iroEN), and yersiniabactin (ybtAEPQSTUX); and the type 3 fimbriae-encoding system (mrkACDF). Moreover, v_5377 and v_5429 (cofT, CFA/III (CS8)) located on plasmid 1 were simultaneously predicted to be virulence genes. After the long-term combination use of antibiotics, the patient successfully recovered. In summary, our study clarified the clinical and molecular characteristics of a rare ST11-K47 CR-hvKP (HvKp-su1), raising great concerns about the emergence of ST11-K47 CR-hvKP with multidrug resistance and hypervirulence, and providing insights into the control and treatment of liver abscess caused by ST11-K47 CR-hvKP.

[Bacterial hepatobiliary infections : Pathogen spectrum, antimicrobial resistance and current treatment concepts]

Ascending cholangitis and pyogenic liver abscesses are acute febrile bacterial hepatobiliary diseases. Nowadays they frequently occur in patients with structural changes of the biliary system and are usually treated by a combination of interventional drainage procedures and antimicrobial therapy. While Gram-negative Enterobacterales were identified as major causes in the past, biliary tract interventions and antibiotic exposure have contributed to an increase in enterococcal species and extended spectrum beta-lactamase (ESBL)-producing Enterobacterales. When selecting an appropriate empirical treatment the treating internist must consider local and individual risk factors for antimicrobial resistance in addition to pharmacokinetic aspects and disease severity to reduce the likelihood of treatment failure.

Interaction of Klebsiella pneumoniae with tissue macrophages in a mouse infection model and ex-vivo pig organ perfusions: an exploratory investigation

Background

Methods

Findings

Interpretation

Funding

Septic Shock Secondary to a Pyogenic Liver Abscess Following Complicated Appendicitis

Pyogenic liver abscesses (PLAs) are a rare condition in North America and Europe and, rarer still, the cause of septic shock. This case report will describe the rare occurrence of a PLA producing septic shock in a 36-year-old male residing in the United Kingdom following a case of complicated appendicitis.

The patient presented to the emergency department (ED) with a three-week history of intermittent loose stools, cramping abdominal pain, recurrent fevers, a heart rate of 111 beats per minute, a blood pressure of 94/58 mmHg, and a fever of 40.1 degrees Celsius. Despite prompt broad spectrum antibiotic administration and three liters of fluid resuscitation, the patient remained shocked which led to an ICU admission.

A CT scan prior to transfer found a 7 cm x 6 cm x 6 cm lesion representing a liver abscess (LA) as well as gross inflammatory change affecting the distal small bowel. The LA was managed through insertion of a percutaneous drain under ultrasound guidance performed by the interventional radiology team, as well as ongoing IV antibiotics. Following growth of the gut commensal Streptococcus constellatus from the abscess fluid culture, a colonoscopy was performed which found a severely distorted and inflamed terminal ileum with an impassable stricture, raising not only the suspicion of appendicitis but also Crohn’s disease.

Following the colonoscopy, after a total of 10 days admission, the patient was allowed to go home with a four-week course of oral co-amoxiclav. After discharge, the patient’s case was discussed in the gastroenterology inflammatory bowel disease (IBD) multi-disciplinary team meeting due to concerns raised about possible Crohn’s disease from the admission CT and following colonoscopy findings. Given the absence of relevant IBD symptoms, a reassuring outpatient MRI small bowel scan (found considerable resolution of the right iliac fossa inflammatory process) and a fecal calprotectin of 29 four months post discharge (normal=0-51 μg/g), it was concluded the terminal ileum changes were most likely accounted for by a complicated course of appendicitis. When reviewed in a telephone clinic 10 weeks post discharge, he was found to have no persistent gastrointestinal (GI) symptoms and was subsequently discharged.

This case highlights the importance of comprehensive imaging and colonoscopy in the work up of those patients with PLAs with no otherwise evident precipitating factor.

Successful Medical Treatment for Peritonitis Resulting from a Large Pyogenic Liver Abscess Rupture

The rupture of a pyogenic liver abscess (PLA) with peritonitis is a rare occurrence but a surgical emergency with a high mortality rate in the case of gas-forming PLA. Rare cases of ruptured PLA that recovered completely with only medical treatment have been reported. This paper reports a case of a large PLA rupture with peritonitis. In this case, surgical intervention was too risky because of the patient's age and poor general condition. The patient recovered fully with appropriate antibiotic therapy and sufficient percutaneous drainage. Therefore, medical treatment may be considered an alternative option in cases of a ruptured large PLA with peritonitis if surgical intervention is too risky.

Clinical characteristics and management of 1572 patients with pyogenic liver abscess: A 12-year retrospective study

BACKGROUND & AIMS

Pyogenic liver abscesses (PLA) are space-occupying lesions in the liver that produce high morbidity and mortality. The clinical characteristics and prognosis of abscesses is different depending on the bacterial culture results and require different strategies for management. The aim of this study was to investigate the clinical characteristics and prognostic factors of patients with PLA.

METHODS

Clinical features, laboratory tests and etiology of PLA between 2006 to 2011 and 2012 to 2017 in a single hospital were retrospectively reviewed. The incidence and mortality of PLA caused by Escherichia coli and Klebsiella pneumoniae were compared and the risk factors for multiple organ dysfunction (MODS) and endophthalmitis were evaluated.

RESULTS

Among the 1,572 PLA patients, the proportion with PLA increased from 333 (21.2%) in 2006-2011 to 1,239 (78.8%) in 2012-2017 without any investigation and treatment procedure differences. K pneumoniae was the main isolate in analysed pus cultures (85.6%). The mortality rate of patients with K pneumoniae infection was lower in the latter period (6.7% vs 0.7%, P = .035). Multivariate analyses revealed that age, fever, MODS and length of hospital stay were factors affecting poor prognosis (death + unhealed/uncured) in PLA patients after treatment and that cardiovascular disease, pleural effusion and pulmonary infection were risk factors for MODS, while diabetes mellitus was the only risk factor for endophthalmitis. Most patients (95.5%) with PLA recovered after abscess drainage/puncture and antibiotic therapy.

CONCLUSIONS

Pleural effusion, fever, MODS and length of hospital stays were factors useful in predicting PLA outcomes.

Pyogenic Liver Abscess and Endogenous Endophthalmitis Due to K64-ST1764 Hypervirulent Klebsiella pneumoniae: A Case Report

RATIONALE

Klebsiella pneumoniae (K. pneumoniae, KP) are divided into two types: classic K. pneumoniae (cKP) and hypervirulent K. pneumoniae (hvKP). hvKP causes liver abscess and metastatic infection. Here, we report one case with pyogenic liver abscess (PLA) and endogenous endophthalmitis (EE) due to a relatively rarely reported serotype of K. pneumoniae in China.

PATIENT CONCERNS

An 80-year old man presented with nausea, vomiting, and epigastric discomfort for 2 weeks.

DIAGNOSES

PLA was identified by CT scan and abdominal ultrasound. Urgent ophthalmologic consultation was performed. B-scan ocular ultrasound was done and he was diagnosed as EE.

INTERVENTIONS

Antibiotic treatment, intravitreal injection of eyes and eye drops were given. Percutaneous needle aspiration, evisceration, and drainage of the right eye were performed.

OUTCOMES

Cultures of the blood, the aspirated pus from the liver abscess, and the contents of the eyeball all yielded K. pneumoniae with a positive string test. The capsular serotype was K64. According to the existence of multiple virulence genes and the severe invasive clinical manifestation, this strain is regarded as a hvKp strain. Multilocus sequence typing (MLST) revealed the sequence type (ST) of this strain was K64-ST1764. Antimicrobial resistance genes, bla _NDM-1 and bla _KPC-2, were not detected in the genome. The patient lost his eyesight but his symptoms subsided. During 15 months follow-up, the result was satisfactory.

LESSONS

Here, we report one case with PLA due to a relatively rarely reported serotype of K. pneumoniae in China. This K64 K. pneumoniae strain is confirmed as hvKp by multiple methods. It is noteworthy that the sequence type is K64-ST1764 instead of the commonest ST11. Moreover, this strain is not considered a K. pneumoniae carbapenemase-producing K. pneumoniae (KPC-Kp) or a carbapenem-resistant K. pneumoniae (CRKP) as it is usually. Further follow-up and research are required to investigate this strain.

Increased incidence of and microbiologic changes in pyogenic liver abscesses in the Mexican population

BACKGROUND

Pyogenic liver abscess (PLA) is a rare disease with an estimated incidence that varies widely across the globe, being as high as 115.4/100000 habitants in Taiwan and as low as 1.1-1.2/100000 habitants in Europe and Canada. Even though there are multiple microorganisms capable of producing an abscess in the liver, including Entamoeba histolytica, fungi, and viruses, most abscesses are derived from bacterial infections. The epidemiology of PLA in Mexico is currently unknown.

AIM

To describe the clinical, demographic and microbiologic characteristics of PLA in Mexico.

METHODS

This is a retrospective study carried out in two centers, and included patients seen between 2006 and 2018 with the diagnosis of pyogenic abscess. We collected demographic, clinical, and microbiological information, treatment, complications, and outcomes. A logistic regression analysis was used to determine the association between different variables and mortality rates.

RESULTS

A total of 345 patients were included in this study. 233 (67.5%) had confirmed PLA, 133 (30%) patients had no positive culture and negative serology and 9 (2.5%) had mixed abscesses. The mean age was 50 years (ranging from 16-97 years) and 63% were female. 65% of the patients had positive cultures for Extended Spectrum Beta-Lactamases (ESBL)-Escherichia coli and Klebsiella pneumoniae. Cefotaxime was administered in 60% of cases. The most common sources of infection were ascending cholangitis and cholecystitis in 34 (10%) and 31 (9%), respectively. The median length of hospital stay was 14 d. 165 patients underwent percutaneous catheter drainage. The inpatient mortality rate was 63%. Immunocompromised state [OR 3.9, 95%CI: 1.42-10.46], ESBL- Escherichia coli [OR 6.7, 95%CI: 2.7-16.2] and Klebsiella pneumoniae [OR 4-8, 95%CI: 1.6-14.4] predicted inpatient mortality by multivariate analysis.

CONCLUSION

The prevalence of PLA is increasing in Mexico and has a very high mortality rate. ESBL-Escherichia coli and Klebsiella pneumoniae are the most common microorganisms causing PLA and are independent predictors of inpatient mortality.

Clinical and computed tomography features of extended-spectrum β-lactamase-producing Klebsiella pneumoniae liver abscess

Background

Klebsiella pneumoniae (KP) is the primary pathogen associated with pyogenic liver abscesses (PLAs). Moreover, there has been an increase in the proportion of extended-spectrum beta-lactamase (ESBL)-producing KP. However, the clinical and computed tomography (CT) features of liver abscesses caused by ESBL-producing KP have not been separately described. We aimed to compare the clinical and CT features present in patients with ESBL-producing and non-ESBL-producing KP as well as to determine the risk factors for ESBL-producing KP liver abscesses (KPLAs).

Methods

We performed a retrospective analysis of data obtained from the medical records of patients with a first episode of KPLA admitted to Shengjing Hospital of China Medical University between May 2015 and May 2019. We compared the clinical and CT features between patients with ESBL-producing and non-ESBL-producing KPLA.

Results

We enrolled 100 patients with KPLA (14 and 86 in the ESBL-producing and non-ESBL-producing groups, respectively). There was no significant between-group difference in the proportion of patients with comorbid diabetes (71.43% vs. 66.2%, p = 0.086). The ESBL-producing KPLA group had a greater proportion of patients with a history of biliary disease (78.57% vs. 26.74%, p < 0.001) and gastrointestinal malignancy (50% vs. 6.98%, p < 0.001). Multivariate regression analysis showed that a history of biliary disease was an independent risk factor for ESBL-producing KPLA. Compared with the non-ESBL-producing KPLA group, the ESBL-producing KPLA group had a significantly higher intensive care unit (ICU) admission rate (28.57% vs. 2.33%, p < 0.001). All ESBL-producing KP isolates were susceptible to carbapenems and amikacin. Only the presence of multiloculation on CT was found to be significantly different between the groups (50% vs. 82.56%, p = 0.012).

Conclusions

The presence of biliary disease was an independent risk factor for ESBL-producing KPLA. Patients with ESBL-producing KPLA had a higher ICU admission rate, with only half of patients having evidence of multiloculation on CT.

Pyogenic liver abscess in liver transplant recipient: A warning signal for the risk of recurrence and retransplantation

BACKGROUND

Pyogenic liver abscesses in liver transplant recipients (PLA-LTR) are a rare disease whose specificities compared with PLA in non-transplanted patients (PLA-C) are unknown.

METHODS

A retrospective case-control study was conducted in a French academic hospital from January 1, 2010, to December 31, 2014.

RESULTS

Among 176 patients diagnosed with PLA, 14 were LTR; each case was matched with 3 PLA-C controls by date of PLA diagnosis and pathophysiological mechanism of PLA. Median time from liver transplantation to PLA diagnosis was 34.5 months. Among 14 PLA-LTR, 8/14 (57.1%) had bacteremia and 10/14 (71.4%) had positive PLA cultures. Most commonly isolated bacteria were Enterobacteriaceae (9/14; 64.3%), Enterococcus spp. (4/14; 28.6%), and anaerobic bacteria (3/14; 21.4%). Clinical, radiological, and microbiological characteristics did not significantly differ between PLA-LTR and PLA-C but there was a tendency toward more diabetic patients and a less acute presentation. All but one PLA-LTR were associated with ischemic cholangitis, whereas this was a rare cause among PLA-C (13/14 vs 3/42, respectively, P < .001) among patients with PLA-LTR. In contrast, hepatobiliary neoplasia was rare in PLA-LTR but frequent in PLA-C (1/14 vs 24/42, P = .001). No significant difference was found between PLA-LTR and PLA-C in terms of duration of antibiotic therapy (6.5 and 6 weeks, respectively), PLA drainage rates (10/14 and 26/42, respectively), or mortality at 12 months after PLA diagnosis (2/14 and 5/42, respectively). Recurrence rates within the first year were observed in 6/14 patients (42.9%), and retransplantation was needed in 5/14 (35.7%).

CONCLUSIONS

Occurrence of PLA in LTR is a severe event leading to high risk of recurrence and retransplantation.

Pyogenic and Amebic Infections of the Liver

Pyogenic liver abscesses are classified by the bacteria that have caused the abscess because this guides treatment and can point to the underlying cause. The most common cause is biliary disease. The diagnosis is made by imaging. Treatment is a combination of antibiotics and percutaneous drainage. Amebic liver abscess is caused by extraintestinal spread of Entamoeba histolytica. E histolytica is spread by fecal-oral transmission and typically colonizes the gastrointestinal tract. It is diagnosed based on imaging and the mainstay of treatment is metronidazole. Only about 15% of cases require percutaneous drainage. The prognosis is good, with almost universal recovery.

The increased recurrence rate of liver abscess caused by extended-spectrum β-lactamase-producing Klebsiella pneumoniae

The pathogenic bacterium Klebsiella pneumoniae (KP) is the major causative agent of pyogenic liver abscess (PLA). But reports about the prognosis of KP-caused PLA (KPLA) are rare. This study aimed to ascertain the recurrence rate of KPLA after initial treatment and its contributing factors. A total of 110 patients who had first-time episodes of KPLA were included into the study. The average follow-up time was 3.65 ± 2.18 years. Twenty (18.18%) KPLA patients experienced recurrence. Those in the recurrence group had a significantly greater incidence of extended-spectrum β-lactamase (ESBL) production compared with the non-recurrence group (30.0% vs 8.89%, P = 0.018). Diabetes, biliary tract disease, and history of malignancy were not associated with recurrence (all P > 0.05). No difference in the CT characteristics of KPLA (including abscess size, location, whether multilocular, gas production of KPLA, and thrombophlebitis) was found between the two groups. Multivariate regression analysis showed that ESBL production (OR, 6.3; 95% CI, 1.02-38.59; P = 0.04) was an independent risk factor for the recurrence of KPLA. Our findings emphasize that KPLA has a high recurrence rate and ESBL production is an independent risk factor for recurrent KPLA.

Pyogenic liver abscess: Clinical features and microbiological profiles in tertiary care center

Background:

Pyogenic liver abscess (PLA) is the end result of a number of pathologic processes that cause a suppurative infection of the liver parenchyma.

Materials and Methods:

Sixty-five patients of age more than 18 years and radiologically confirmed cases of liver abscess were included in this study. Pus and blood samples were collected. Pus was processed for microscopy of trophozoite of Entamoeba histolytica and aerobic and anaerobic bacterial culture. Blood was processed for antibody ELISA for Entamoeba histolytica and aerobic bacterial culture. Identification of aerobic and anaerobic isolates was done by Vitek2 and antibiotic sensitivity test for aerobic bacterial isolates was done by Vitek2.

Result:

Out of sixty five, twenty five were confirmed as PLA. All patients were male with mean age 37.9 years. Fever and upper abdominal pain were the most common symptoms. Right lobe comprised 80% of the abscess. Pus sample was more sensitive than blood sample for diagnosis. There were a total of 33 isolates in our study. Klebsiella pneumoniae (6/33) was the most common aerobic isolate and Clostridium spp. (7/33) was the anaerobic isolate. All gram-negative bacteria were showing good sensitivity for 3^rd and 4^th generation cephalosporins, fluoroquinolones, amikacin, gentamicin, piperacillin-tazobactam, imipenem and meropenem. Abscess >5 cm was treated with percutaneous drainage while abscess <5 cm was treated with antibiotics only.

Conclusion:

Diagnosis should be made with the combination of clinical suspicion, radiology, and microbiology. Empirical therapy should include anaerobic coverage too. Only antibiotic therapy can be given under consideration of size of abscess, persistence of fever after giving antibiotics, and any suspected complications.

Hypervirulent Klebsiella pneumoniae

Hypervirulent K. pneumoniae (hvKp) is an evolving pathotype that is more virulent than classical K. pneumoniae (cKp). hvKp usually infects individuals from the community, who are often healthy. Infections are more common in the Asian Pacific Rim but are occurring globally. hvKp infection frequently presents at multiple sites or subsequently metastatically spreads, often requiring source control. hvKp has an increased ability to cause central nervous system infection and endophthalmitis, which require rapid recognition and site-specific treatment. The genetic factors that confer hvKp's hypervirulent phenotype are present on a large virulence plasmid and perhaps integrative conjugal elements. Increased capsule production and aerobactin production are established hvKp-specific virulence factors. Similar to cKp, hvKp strains are becoming increasingly resistant to antimicrobials via acquisition of mobile elements carrying resistance determinants, and new hvKp strains emerge when extensively drug-resistant cKp strains acquire hvKp-specific virulence determinants, resulting in nosocomial infection. Presently, clinical laboratories are unable to differentiate cKp from hvKp, but recently, several biomarkers and quantitative siderophore production have been shown to accurately predict hvKp strains, which could lead to the development of a diagnostic test for use by clinical laboratories for optimal patient care and for use in epidemiologic surveillance and research studies.

Antibiotic Resistance and Clinical Presentation of Health Care-Associated Hypervirulent Klebsiella pneumoniae Infection in Korea

Hypervirulent Klebsiella pneumoniae typically presents as a community-acquired infection causing a liver abscess. It is often associated with rmpA and magA genes and confers a mucoid phenotype. Our aim was to evaluate the clinical presentation and antibiotic resistance of hypervirulent K. pneumoniae (hvKP) of health care-associated origin. The study was performed on 414 K. pneumoniae isolates recovered from patients that visited our hospital from December 2013 through November 2015. Hypervirulence was determined by the presence of a hypermucoviscous phenotype, in 155 isolates (37.4%). We compared health care-associated hvKP infections with community-acquired infections. The hypermucoviscous phenotype was 60 isolates (24.2%) in health care-associated infection and 90 isolates (53.8%) in community-acquired infection. Respiratory infection was the most common source of health care-associated K. pneumoniae. Antibiotic resistance was higher in health care-associated hvKP infections, which were more frequently associated with non-K1/K2 serotypes and less frequently associated with rmpA gene. In our study, 38% of hvKP was health care associated. Pneumonia is the most common infection, besides intraabdominal infection, in community-originating strains. These results suggest that health care-associated hvKP may have different microbiological characteristics from classical community-associated infections. Further investigation is needed for other virulent factors associated with health care-associated hvKP.

A comparison of pyogenic liver abscess in patients with or without diabetes: a retrospective study of 246 cases

Background

Pyogenic liver abscess(PLA) has become common in patients with diabetes mellitus (DM), but it is unclear whether differences exist between patients with and without DM. A retrospective study was performed to identify these differences, summarize the clinical experience, and improve the diagnosis and treatment of PLA.

Methods

The patients were enrolled in a teaching hospital from January 2012 to December 2016. The patients were separated into two groups based on comorbidity with diabetes mellitus (DM). The DM group was further separated into two subgroups according to the HbA1C concentration to investigate whether glycaemic control affected the clinical characteristics of PLA patients with DM. Chi-square, Fisher’s exact test, and t-tests were used to analyse and evaluate differences between the two groups.

Results

Two hundred and forty-six PLA patients were identified and 90 (36.6%) had comorbid DM. Patients with DM were older, had higher levels of alkaline phosphatase and γ-glutamyl transferase, hypertension, a loss of body weight, a single abscess, and combined antibiotic therapy with the use of carbapenems and Klebsiella pneumoniae in their blood cultures but a less frequent history of abdominal surgery and Escherichia coli in their pus cultures. When DM patients were compared to non-DM patients, each of these differences was significant (P < 0.05). Diabetic PLA patients with poor glycaemic control had a significantly higher proportion of fever and both lobes abscess(P < 0.05).

Conclusion

PLA patients with diabetes are older, have more serious complications, a higher prevalence of cardiovascular disease, an increased use of combined antibiotic therapy with carbapenem, and K. pneumoniae as the predominant pathogen, but these patients had fewer abdominal surgeries and fewer E. coli infections. In addition, poorly controlled glycaemia in diabetic PLA patients is associated with high incidence of fever and both lobes abscess.

Cryptogenic and non-cryptogenic liver abscess: A retrospective analysis of 178 cases revealed distinct characteristics

Objective

To enhance theoretical support of pyogenic liver abscess (PLA) treatment by comparing characteristics of patients with either PLA with an identified infectious origin (non-cryptogenic) or PLA with no obvious underlying cause (cryptogenic).

Methods

This retrospective study included all first episodes of PLA in adults admitted to a tertiary hospital between 2009 and 2016. Relevant clinical data were collected for patients with cryptogenic or non-cryptogenic PLA and compared across a number of characteristics.

Results

In all, 178 patients were included: 111 cases (62.4%) of cryptogenic PLA, and 67 cases (37.6%) of non-cryptogenic PLA. Diabetes mellitus was significantly more prevalent in patients with cryptogenic PLA than those with non-cryptogenic PLA. The proportion of multidrug resistance/poly-microbial infection was significantly lower and Klebsiella pneumoniae infection was significantly higher in the cryptogenic versus non-cryptogenic PLA group. Metastatic infection occurred in four patients with cryptogenic PLA only, and all had diabetes and K. pneumoniae infection. Multivariate logistic regression analysis revealed that male sex, diabetes and K. pneumoniae were independent predictors for cryptogenic PLA.

Conclusions

Cryptogenic and non-cryptogenic PLA have distinctly different characteristics, suggesting a potential need for different treatment approaches.

Carbapenem Nonsusceptible Klebsiella pneumoniae in Taiwan: Dissemination and Increasing Resistance of Carbapenemase Producers During 2012-2015

Before 2011, the prevalence rates of carbapenemase-producing Klebsiella pneumoniae (CPKP) among carbapenem nonsusceptible K. pneumoniae (CnSKP) isolates were below 10% in Taiwan. The study presents the dissemination and increased antimicrobial resistance of CPKP from January 2012 to August 2015, as shown by Taiwanese multicenter surveillance. Isolates with minimum inhibitory concentrations (MICs) of >1 μg/mL for imipenem or meropenem were collected, screened for various carbapenemase genes by PCR, and tested for antimicrobial susceptibility. Among 1,457 CnSKP isolates, 1,250 were collected from medical centers. The CnSKP prevalence in medical centers increased by 1.7-fold during the study. Among all CnSKP isolates, 457 were CPKP. The CPKP rate among CnSKP increased by 1.5-fold and reached 36.8% in 2015. The CPKP nonsusceptibility rate to aztreonam, fluoroquinolones, and aminoglycosides increased yearly. Six CPKP isolates carried dual carbapenemase genes. Three Ambler classes were identified in 451 isolates with a single carbapenemase: classes A (315 blaKPC-2, 2 blaKPC-3, 28 blaKPC-17, 2 blaKPC-34), B (26 blaIMP-8, 2 blaNDM-1, 36 blaVIM-1), and D (40 blaOXA-48). The blaOXA-48 rate among CPKP increased by 6-fold over three years. Most KPC and OXA-48 producers were ST11. CnSKP was increasingly prevalent, owing to CPKP dissemination. Additionally, CPKP became more resistant during the study period.