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

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.

Epidemiological Features and Impact of High Glucose Level on Virulence Gene Expression and Serum Resistance of Klebsiella pneumoniae Causing Liver Abscess in Diabetic Patients

Purpose

Klebsiella pneumoniae (K. pneumoniae) is a Gram-negative bacterium that is predominantly associated with liver abscesses in global diabetic patients. High levels of glucose in the surrounding of K. pneumonia increase its pathogenicity including capsular polysaccharide (CPS) and fimbriae. Other important virulent factors include outer membrane protein A (ompA) and regulator mucoid phenotype A (rmpA). The objective of this investigation was to elucidate the effects of high glucose on rmpA and ompA gene expression and serum resistance of K. pneumoniae causing liver abscess.

Patients and Methods

The clinical history of 57 patients suffering from K. pneumoniae-caused liver abscesses (KLA) was acquired and their clinical and laboratory manifestations in the presence or absence of diabetes were analyzed. The antimicrobial susceptibility, serotypes, and virulence genes were tested. Clinical isolates of 3 serotype-K1 hypervirulent K. pneumoniae (hvKP) were used to detect the effect of exogenous high glucose on rmpA, ompA, and clbB genes expression, and bacterial serum resistance.

Results

KLA patients with diabetes showed higher C-reactive protein (CRP) compared to non-diabetic KLA patients. Furthermore, the diabetic group showed increased incidences of sepsis and invasive infections, and their length of hospital stay was also prolonged. Pre-incubation of K. pneumoniae in high glucose (0.5%) concentration up-regulated rmpA, ompA, and clbB genes expression. However, cAMP supplementation, which was inhibited by environmental glucose, reversed the increase of rmpA and ompA in a cAMP-dependent manner. Moreover, hvKP strains incubated in high glucose also exhibited enhanced protection from serum killing.

Conclusion

High glucose levels reflected by poor glycemic control has increased gene expression of rmpA and ompA in hvKP by the cAMP signaling pathway and enhanced its resistance to serum killing, thus providing a new and reasonable explanation for the high incidences of sepsis and invasive infections in KLA patients with diabetes.

Development and validation of a prediction model based on clinical and CT features for invasiveness of K. pneumoniae liver abscess

OBJECTIVES

Klebsiella pneumoniae liver abscess (KPLA) complicated with extrahepatic migratory infection (EMI) is defined as invasive KPLA. The current study aimed to develop and validate a risk prediction model for the invasiveness of KPLA.

METHODS

From 2010 to 2020, KPLA patients from four institutes were selected retrospectively. In the development cohort, risk factors from a logistic regression analysis were utilized to develop the prediction model. External validation was performed using an independent cohort.

RESULTS

A total of 382 KPLA patients comprised two separate cohorts: development cohort (institute 1, n = 286) and validation cohort (institute 2-4, n = 86). The overall incidence of EMI was 19.1% (development cohort, n = 55; validation cohort, n = 18, p > 0.05). In the development cohort, four risk factors (age ≤ 40 years, fasting blood glucose (FBG) > 7 mmol/L, no rim enhancement, and thrombophlebitis on CT), significantly associated with EMI, were incorporated into the scoring system. The area under curve (AUC) of the receiver operating characteristic curve (ROC) in the development and validation cohorts was 0.931 (95% confidence interval [CI]: 0.93-0.95) and 0.831 (95% CI: 0.86-0.91), respectively. The calibration curves fitted well. The incidence of EMI was 3.3% and 56.5% for the low- (total scores ≤ 4) and high-risk (total scores > 4) groups in the development cohort, and 3.2% and 66.7% in the validation cohort (all p < 0.001), respectively.

CONCLUSIONS

Age ≤ 40 years, FBG > 7 mmol/L, no rim enhancement, and thrombophlebitis were independent risk factors for EMI. This validated prediction model may aid clinicians in identifying KPLA patients at increased risk for invasiveness.

KEY POINTS

• Four risk factors are significantly associated with extrahepatic migratory infections (EMI): age ≤ 40 years, fasting blood glucose (FBG) > 7 mmol/L, no rim enhancement, and thrombophlebitis on CT. • Based on these risk factors, the current study developed and validated a prediction model for the invasiveness of Klebsiella pneumoniae liver abscess (KPLA). • This validated prediction model may in the help early identification of KPLA patients at increased risk for invasiveness.

[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.

Lactobacillus gasseri liver abscess and bacteremia: a case report

BACKGROUND

Lactobacillus is a genus of Gram-positive non-spore-forming rods usually found in the microbiota of the oral cavity, gastrointestinal tract, and female genitourinary tract. Also, they are commonly used in the food industry as supplements and probiotics. Lactobacilli are normally considered non-pathogenic to the human body, however, under certain circumstances such as immunosuppression, they can cause severe infections, with only a few cases of bacteremia, infective endocarditis, pneumonia, meningitis, and intra-abdominal infections reported. Among these presentations, a pyogenic liver abscess is rather rare.

CASE PRESENTATION

We describe the case of a 59-year-old man with a history of diabetes mellitus and multiple abdominal surgeries with the latest being in 2014 presenting with bacteremia and multiple large pyogenic liver abscesses due to Lactobacillus gasseri, which did not appear to be related to the use of probiotics or immunosuppression.

CONCLUSIONS

Given the high prevalence of diabetes mellitus and the increased use of probiotics, it is expected that in the future we will see an increase in infections caused by Lactobacilli. Medical management with antibiotics and percutaneous drainage were successful strategies for the treatment of this unusual case of pyogenic liver abscesses and bacteremia caused by Lactobacillus gasseri.

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.

Acute Streptococcus constellatus Pyogenic Liver Abscess Due to an Atypical Presentation of Sigmoid Diverticulitis Complicated by Pericolonic Abscess

Diverticulitis is a result of diverticulum inflammation that involves protrusion of the colonic wall. It is considered to be complicated when associated with an abscess, fistula, perforation of large bowel, or obstruction. The incidence of diverticulitis increases with age, and it most commonly presents as constant abdominal pain in the left lower quadrant. We report a case of a 54-year-old male with a history of hypertension who was admitted to our hospital with systemic symptoms and right shoulder pain noted to have Streptococcus constellatus bacteremia and an incidental finding of a single large hepatic abscess on chest imaging. Additional imaging studies revealed the presence of acute sigmoid diverticulitis complicated by pericolonic abscess. He had no known risk factors and had not experienced any abdominal pain before admission. 

A liver abscess due to S. constellatus is a rare complication from sigmoid diverticulitis, and there are only a few cases reported as per the PubMed medical literature review. Only four other unique cases with few or no risk factors were discovered to have a pyogenic liver abscess initially, and later source was found to be due to perforated diverticulitis. Due to this rare clinical presentation, diagnosis is often delayed leading to complications requiring surgical intervention. This can result in higher mortality. Our patient had ultrasound-guided drainage of the abscess and completed a six-week course of intravenous antibiotics (ceftriaxone and metronidazole) with successful recovery. 

Endogenous endophthalmitis in Klebsiella pneumoniae pyogenic liver abscess: Systematic review and meta-analysis

BACKGROUND

Endogenous endophthalmitis (EE) is a devastating complication that develops as a metastatic infection in patients with Klebsiella pneumoniae pyogenic liver abscess (KPPLA). The existing data are heterogeneous and the actual disease burden and risk factors for the development of EE among patients with KPPLA have not been systematically examined. We performed a systematic review and meta-analysis to examine the incidence of EE, temporal trend of EE, and risk factors for EE in patients with KPPLA.

METHODOLOGY

The MEDLINE, EMBASE, Web of Science, and Cochrane Library databases were searched for articles published from inception to 2020 that evaluated the incidence of EE among patients with KPPLA. By a random-effects method, a pooled estimate of its incidence with 95% confidence intervals was estimated along with examination of its temporal and geographic variations. Pooled odds ratios were calculated for risk factors.

RESULTS

Fifteen retrospective studies reporting data on 11889 patients with KPPLA met the inclusion criteria and were analyzed. With 217 patients developing EE, the pooled incidence of EE was 4.5% (95% confidence interval 2.4% to 8.2%). The heterogeneity was considerable and significant (Cochran's Q 243.5, p < 0.001, I² = 94.2%).

CONCLUSION

This meta-analysis estimates the actual incidence of EE among patients with KPPLA, where EE is reported in about 1 of 22 patients with KPPLA. Infection caused by K1 capsular serotype was an independent risk factor.

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.