Liver abscess metastasizing to prostate and lung

Prostatic Abscess Combined With Spleen Abscess Due to Multi-Drug-Resistant Gram-Negative Bacilli: A Case Report and Literature Review

The prostatic abscess is a rare complication of a bacterial infection of the prostate. Since the early use of potent antibiotics to treat urinary tract infections, the incidence of the prostatic abscess has declined significantly. In keeping with that, prostatic abscess combined with abscesses in the spleen or other distant organs become an extremely rare but fatal clinical condition. Here, we present a case of prostate and spleen abscess due to multi-drug-resistant gram-negative bacilli without obvious risk factors. The patient initially complained of high-grade fever and dysuria. After screening the source of infection by computed tomography (CT) scans, prostate and spleen abscesses were diagnosed. In addition, extended-spectrum beta-lactamase positive Escherichia coli was detected both in urine and blood culture. The patient was successfully treated by a transurethral resection of the prostate followed by splenic puncture and drainage, as well as intravenous administration of meropenem. Although the prostate abscess combined with spleen abscess was rare, the possibility of dissemination in remote tissues should be taken into consideration before the surgical treatment of prostatic abscesses. The concurrent drainage of multiple abscesses followed by intensive and sensitive antibiotics was safe and effective for indicated patients.

Hypervirulence and hypermucoviscosity: Two different but complementary Klebsiella spp. phenotypes?

Since the hypermucoviscous variants of Klebsiella pneumoniae were first reported, many cases of primary liver abscesses and other invasive infections caused by this pathogen have been described worldwide. Hypermucoviscosity is a phenotypic feature characterized by the formation of a viscous filament ≥5 mm when a bacterial colony is stretched by a bacteriological loop; this is the so-called positive string test. Hypermucoviscosity appears to be associated with this unusual and aggressive type of infection, and therefore, the causal strains are considered hypervirulent. Since these first reports, the terms hypermucoviscosity and hypervirulence have often been used synonymously. However, new evidence has suggested that hypermucoviscosity and hypervirulence are 2 different phenotypes that should not be used synonymously. Moreover, it is important to establish that a negative string test is insufficient in determining whether a strain is or is not hypervirulent. On the other hand, hypervirulence- and hypermucoviscosity-associated genes must be identified, considering that these phenotypes correspond to 2 different phenomena, regardless of whether they can act in synergy under certain circumstances. Therefore, it is essential to quickly identify the genetic determinants behind the hypervirulent phenotype to develop effective methodologies that can diagnose in a prompt and effective way these hypervirulent variants of K. pneumoniae.

Morganella morganii, a non-negligent opportunistic pathogen

Morganella morganii belongs to the tribe Proteeae of the Enterobacteriaceae family. This species is considered as an unusual opportunistic pathogen that mainly causes post-operative wound and urinary tract infections. However, certain clinical M. morganii isolates present resistance to multiple antibiotics by carrying various resistant genes (such as blaNDM-1, and qnrD1), thereby posing a serious challenge for clinical infection control. Moreover, virulence evolution makes M. morganii an important pathogen. Accumulated data have demonstrated that M. morganii can cause various infections, such as sepsis, abscess, purple urine bag syndrome, chorioamnionitis, and cellulitis. This bacterium often results in a high mortality rate in patients with some infections. M. morganii is considered as a non-negligent opportunistic pathogen because of the increased levels of resistance and virulence. In this review, we summarized the epidemiology of M. morganii, particularly on its resistance profile and resistant genes, as well as the disease spectrum and risk factors for its infection.

Klebsiella pneumonia-induced prostate abscess: How to work it up?

INTRODUCTON

Klebsiella pneumonia (KP) is related to a metastatic phenomenon from the originally affected primary organ. About 28% of patients with pyogenic liver abscess arising from KP suffer from metastatic complications. This study was done to define the clinical features of KP-induced prostate abscess.

METHODS

A total of 14 patients were diagnosed with prostate abscess based on clinical, laboratory examination and abdominopelvic computed tomography (CT) scan from 2007 to 2013.

RESULTS

Among these 14 patients, KP was the dominant causative microorganism in 6 patients (42.9%), followed by Esherchia coli in 2, Pseudomonas aeroginosa in 1, methicillin-resistant Staphyolcoccus aureus in 1, and no growth in either the urine or blood culture in 4. Four (66.7%) of the 6 KP induced-prostate abscess had other concurrent abscess sites besides the prostate: liver in 3, kidney in 1, and perianal area with endogenous endophthalmitis that ended in loss of vision in 1 patient.

CONCLUSIONS

We report on the clinical features of KP-induced prostate abscess based on a small number of patients, which is the main limitation of our study. We believe that if the causative organism of a prostate abscess was KP, more workup would be needed to rule out the presence of an abscess in other organs, especially in the liver. Abdominopelvic CT scan would be a proper imaging modality.

Invasive Klebsiella pneumoniae syndrome in North America

Invasive liver abscess syndrome, which is caused by hypervirulent Klebsiella pneumoniae subtypes, has been emerging worldwide over the past 2 decades. The syndrome is associated with the hypermucoviscosity phenotype of K. pneumoniae strains and with the magA and rmpA genes. We provide the first laboratory evidence of the presence of rmpA-positive K. pneumoniae in North America.

Comparison between pyogenic liver abscess caused by Klebsiella pneumoniae and non-Klebsiella pneumoniae

AIM: To analyze the differences between pyogenic liver abscess caused by Klebsiella pneumoniae (Kp) and non-Klebsiella pneumoniae (NKp), and provide the evidence for early diagnosis and treatment.

METHODS: The clinical data of 162 patients with pyogenic liver abscess from January 2000 to January 2005 were collected, and statistical analysis was performed to compare the differences between the Kp and NKp patients in general characteristics, underlying diseases, clinical manifestations, laboratory features, and characteristics of liver abscess, treatments and outcomes.

RESULTS: Of the 162 patients, 112 (69.1%) were classified into Kp group, and 50 (30.9%) were NKp group. There was significant difference between the two groups in ages (P < 0.05). For underlying diseases, there were significant differences in diabetes (66.1% vs 38.0%, P < 0.01), biliary diseases (14.3% vs 28.0%, P < 0.05) and abdominal injury (5.4% vs 16.0%, P < 0.05) between two groups. For clinical manifestations and laboratory features, there were also significant differences in anemia between two groups (60.7% vs 78%, P < 0.05). For characteristics of liver abscess, solitary liver abscess and monomicrobial isolates were more frequent in the Kp group than those in the NKp group (75.9% vs 58%, P < 0.05; 85.7% vs 64%, P < 0.01). For treatment and outcome, there were significant differences in metastatic infection and mortality rate between two groups (20.5%vs 6%, P < 0.05; 8.9% vs 26.0%, P < 0.01).

CONCLUSION: In comparison with those in NKp patients, the age and mortality rate of Kp patients are lower, and the rate of diabetes and metastatic infection are higher. Monomicrobial isolates are mostly found in Kp patients.

Pyogenic liver abscess with a focus on Klebsiella pneumoniae as a primary pathogen: an emerging disease with unique clinical characteristics

OBJECTIVES

Pyogenic liver abscess is a common intraabdominal infection. Historically, Escherichia coli (E. coli) has been the predominant causative agent. Klebsiella liver abscess (KLA) was first reported in Taiwan and has surpassed E. coli as the number one isolate from patients with hepatic abscesses in that country and reports from other countries, including the United States, have increased. We examined the microbiologic trends of pyogenic liver abscess at our institution to determine if a similar shift in etiologic agents was occurring.

METHODS

We examined all cases of liver abscess at our institution from 1999 to 2003 via a retrospective chart review of inpatient records and reviewed the English literature via a MEDLINE search for all U.S. cases of KLA.

RESULTS

Since 1966, only 12 cases of KLA have been reported in the United States. We report six cases of KLA at our institution alone; 2 patients were not Asian, and 4 were not diabetic. Klebsiella pneumoniae (K. pneumoniae) was the most common cause of pyogenic hepatic abscess at our institution over the last 5-yr period. When comparing Klebsiella versus other causes of pyogenic liver abscess, there were no significant differences in demographics or laboratory findings; however, most of our Klebsiella cases occurred among Filipinos. Review of the 18 cases of K. pneumoniae liver abscess in the United States showed that Klebsiella cases occurred predominantly among middle-aged men; 83% had concurrent bacteremia and 28% had metastatic complications. An increasing number of cases were reported from the United States since the mid-1990s.

CONCLUSIONS

These data suggest that KLA may represent an emerging disease in Western countries, such as the United States. The diagnosis of K. pneumoniae should be considered in all cases of liver abscess, and appropriate antibiotic therapy and a diagnostic work-up for metastatic complications should be employed.