Jiun-Nong Lin

Bacteremia Caused by Extended-Spectrum-β-Lactamase-Producing Escherichia coli Sequence Type ST131 and Non-ST131 Clones: Comparison of Demographic Data, Clinical Features, and Mortality

ABSTRACT Escherichia coli producing the highly virulent, multidrug-resistant, CTX-M-15 extended-spectrum β-lactamase (ESBL), sequence type 131 (ST131), has emerged on three continents since the late 2000s. We described the molecular epidemiology, clinical features, and outcome of ESBL-producing E. coli bacteremia in Taiwan from 2005 to 2010. This study aims to determine whether the risk factors, clinical features, and outcomes of the ST131 isolate differ from those of non-ST131 isolates. From 2005 to 2010, we collected 122 nonduplicated, consecutive, ESBL-producing E. coli isolates from bloodstream infections in a 1,200-bed hospital in Taiwan. Isolates were characterized using multilocus sequence typing. Demographic data, clinical features, and outcomes were collected from medical chart records. Thirty-six (29.5%) patients with bacteremia with ESBL-producing E. coli ST131 were identified. Patients with clone ST131 were more likely to have secondary bacteremia and noncatheterized urinary tract infections (P < 0.05). Secondary bacteremia (odds ratio [OR], 5.05; 95% confidence interval [CI], 1.08 to 23.56) and urinary catheter nonuse (OR, 3.77; 95% CI, 1.17 to 12.18) were independent risk factors for the ST131 clone after adjustment. Mortality rates at day 28 were similar in ST131 and non-ST131 populations. Independent risk factors predicting mortality at day 28 included malignancy, shock, and hospital-acquired bacteremia. In ESBL-producing E. coli bloodstream infections, the ST131 clone was not associated with health-care-associated risk factors, such as urinary catheter use or antibiotic exposure. Although highly virulent and multidrug resistant, the ST131 clone was not associated with higher mortality than non-ST131 clones.

Sphingomonas paucimobilis Bacteremia in Humans: 16 Case Reports and a Literature Review

BACKGROUND/PURPOSE Sphingomonas paucimobilis is a glucose-nonfermenting Gram-negative bacillus that is widely distributed in both natural environment and hospitals. Various infections in humans have been reported, but most have been limited to sporadic case reports. The aim of this study was to describe the clinical characteristics and manifestations of S. paucimobilis bacteremia. We also reviewed the literature on S. paucimobilis bacteremia. METHODS Cases of S. paucimobilis bacteremia were identified retrospectively at a university-affiliated hospital in Taiwan. In addition, relevant case reports were identified through PubMed and reviewed. RESULTS From April 2004 to April 2008, 42 cases of S. paucimobilis bacteremia were identified in this study. Among them, 16 cases were identified from E-Da hospital, Kaohsiung, Taiwan and 26 cases from the literature review. The median age of patients was 48.5 years and 57.1% were male. The most common comorbidities included malignancy (57.1%), immunosuppressant use (40.5%), and diabetic mellitus (11.9%). Hospital-acquired bacteremia accounted for 69.0% of infections. Primary bacteremia and catheter-related bloodstream infection were found in 35.7% and 33.3% respectively. The most effective antibiotics were fluoroquinolones, carbapenems, and beta-lactam/beta-lactamase inhibitor combinations. All 42 patients survived the S. paucimobilis bacteremic episodes, but three patients experienced septic shock. CONCLUSION S. paucimobilis can cause infections in healthy as well as immunocompromised individuals. Although it is an organism of low clinical virulence, infection caused by S. paucimobilis can lead to septic shock. Further clinical research is required to characterize this infection.

Risk factors for mortality of bacteremic patients in the emergency department.

OBJECTIVES Patients with bacteremia have a high mortality and generally require urgent treatment. The authors conducted a study to describe bacteremic patients in emergency departments (EDs) and to identify risk factors for mortality. METHODS Bacteremic patients in EDs were identified retrospectively at a university hospital from January 2007 to December 2007. Demographic characteristics, underlying illness, clinical conditions, microbiology, and the source of bacteremia were collected and analyzed for their association with 28-day mortality. RESULTS During the study period, 621 cases (50.2% male) were included, with a mean (+/-SD) age of 62.8 (+/-17.4) years. The most common underlying disease was diabetes mellitus (39.3%). Escherichia coli (39.2%) was the most frequently isolated pathogen. The most common source of bacteremia was urinary tract infection (41.2%), followed by primary bacteremia (13.2%). The overall 28-day mortality rate was 12.6%. Multivariate stepwise logistic regression analysis showed age > 60 years (odds ratio [OR] = 2.52, 95% confidence interval [CI] = 1.29 to 4.92, p = 0.007), malignancy (OR = 2.66, 95% CI = 1.44 to 4.91, p = 0.002), liver cirrhosis (OR = 2.08, 95% CI = 1.02 to 4.26, p = 0.044), alcohol use (OR = 5.73, 95% CI = 2.10 to 15.63, p = 0.001), polymicrobial bacteremia (OR = 3.99, 95% CI = 1.75 to 9.10, p = 0.001), anemia (OR = 2.33, 95% CI = 1.34 to 4.03, p = 0.003), and sepsis (OR = 1.94, 95% CI = 1.16 to 3.37, p = 0.019) were independent risk factors for 28-day mortality. CONCLUSIONS Bacteremic patients in the ED have a high mortality, particularly with these risk factors. It is important for physicians to recognize the factors that potentially contribute to mortality of bacteremic patients in the ED.

Risk factors of isolated antibody against core antigen of hepatitis B virus: association with HIV infection and age but not hepatitis C virus infection.

Background:Isolated antibody to hepatitis B core antigen (anti-HBc) is defined as seropositivity for anti-HBc in the absence of hepatitis B surface antigen (HBsAg) and antibody to HBsAg (anti-HBs). It is commonly found in HIV-infected persons or hepatitis C virus (HCV)-infected persons, but the risk factors for isolated anti-HBc remain uncertain, especially in regions that are hyperendemic for hepatitis B virus (HBV) infection. Methods:This cross-sectional study included a cohort of 955 nonhemophiliac, HIV-infected patients, diagnosed between 1988 and 2009, and 643 HIV-uninfected injection drug users (IDUs) attending the methadone clinic between August 2007 and May 2009, with available HBV serological data. The medical records were reviewed to identify the risk factors associated with seropositivity of isolated anti-HBc. Results:The overall seroprevalence of isolated anti-HBc was 12.1% (193 of 1598), in which occult HBV infection accounted for 1.6% (3 of 185) and the majority (91.2 %, 176 of 193) had low titers of anti-HBs (3.6 ± 2.9 IU/L). Subjects with isolated anti-HBc were significantly older (40.7 ± 9.3 versus 36.9 ± 8.0, respectively, P < 0.0001). There was a significantly increasing trend in the prevalence of isolated anti-HBc with age, from 4.0% in those younger than 30 years to 22.5% after 50 years of age (test for trend, P < 0.0001). A significantly higher prevalence of isolated anti-HBc was observed in HIV-infected subjects [14.0% (134 of 955) versus 9.2% (59 of 643), adjusted odds ratio, 1.64; P < 0.01], but not in those with HCV infection (P = 0.18). Conclusions:Isolated anti-HBc seropositivity was significantly associated with HIV infection, and older age. HCV infection was not associated with isolated anti-HBc in a country hyperendemic with HBV infection, even in populations with a high prevalence of HCV infection. The majority was not attributable to occult HBV infection, but rather, low level of anti-HBs, suggesting that HBV vaccination may not be required.

Clinical and Molecular Characteristics of Invasive and Noninvasive Skin and Soft-Tissue Infections Caused by Group A Streptococcus

ABSTRACT The severity of skin and soft tissue infections caused by group A Streptococcus (GAS) is variable, and there are only a limited number of studies evaluating the characteristics of these infections in the literature. From May 2005 to November 2007, 73 patients with skin and soft tissue infections caused by group A Streptococcus were included in this study. Among these patients, 34 (46.6%) had invasive diseases. Diabetes mellitus, alcoholism, and hypertension were the most common underlying disorders. The overall mortality rate was 6.8%, and the elderly were predisposed to invasive infections (P < 0.001). Neutrophil percentages of ≥80, serum creatinine levels of ≥2 mg/dl, and high serum C-reactive protein levels were noted more frequently in patients with invasive infections than in patients with noninvasive infections, as were bacteremia and a high mortality rate. Of the 73 isolates, 93.2%, 97.3%, and 37% exhibited susceptibility to erythromycin, clindamycin, and tetracycline, respectively. The five most prevalent emm types were emm106 (24.7%), emm11 (12.3%), emm102 (9.6%), emm4 (8.2%), and emm12 (8.2%). Compared to other types, the emm106 type was significantly more likely to be associated with invasive diseases (P = 0.012). Dendrogram analysis showed a unique SmaI-digested pulsed-field gel electrophoresis pattern of the emm106 type that was particularly prone to cause invasive skin and soft tissue infections (P < 0.001). The results of this study suggest that isolates with the emm106 gene may be an emerging group A Streptococcus strain that causes invasive skin and soft tissue infections. Further surveillance study to understand the significance of this invasive strain is critical.

Renal transplant recipient infected with Penicillium marneffei.

A 42-year-old woman presented to our hospital after 2 months of pain in her left hip. She had received a cadaveric-kidney transplant 9 months earlier at our hospital because of end-stage renal disease. After transplantation, the patient received maintenance immunosuppressants with oral tacrolimus (3 mg twice a day) and prednisolone (5 mg per day). On admission, she was afebrile. Her white-blood-cell count was 9150 cells per μL, with neutrophils of 62%, lymphocytes of 31%, and monocytes of 5%. Radiography showed an osteolytic lesion on her left pelvic brim adjacent to the acetabulum (fi gure). The osteolytic lesion was biopsied using an echoguided needle. Staining with gomori methenamine silver revealed yeast-like fungi with transverse septa (fi gure). At 25°C, this fungus grew as mold on sabouraud dextrose agar and produced a red pigment spreading into the agar (fi gure). On staining with lactophenol cotton blue, the conidiophores of this mold were smooth and had three to fi ve metulae, each of which with several phialides, producing smooth, spherical conidia in chains (fi gure). The mold-to-yeast conversion or phase transition, which is thermally regulated, is a diagnostic characteristic of Penicillium marneff ei. Intravenous liposomal amphotericin B (100 mg; 2 mg/kg body weight per day) was used for 21 days, followed by oral itraconazole (200 mg per day) for 8 months. No relapse of penicilliosis was seen 7 months after ending the antifungal treatment. P marneff ei has been reported to be an opportunistic infection endemic in areas of southeast Asia, including Thailand, southern China, Hong Kong, and Taiwan. Although infections in people with intact immune systems have been documented, the majority of reported cases involve patients with cellular immunity defects, receiving treatment with immunosuppressant drugs, or infected with HIV. Physicians should consider P marneff ei penicilliosis in patients that are immunocompromised who reside in or have a history of travelling to endemic areas.

Characteristics and outcomes of polymicrobial bloodstream infections in the emergency department: A matched case-control study.

OBJECTIVES Polymicrobial bloodstream infection (BSI) is a critical condition and has been increasingly reported; however, the authors were unable to find an emergency department (ED) patient-based study in the literature. METHODS A retrospective matched case-control study with a ratio of 1:3 among patients with polymicrobial BSIs in an ED was conducted. The case group was patients aged > 16 years with polymicrobial BSIs. Patients matched for age and sex with monomicrobial BSIs were sampled as the control group. Demographic information, underlying conditions, microbiologic data, and outcomes were collected for further analysis. RESULTS From January 2005 to December 2007, a total of 112 episodes of polymicrobial BSIs among 109 patients were included. Two pathogens were isolated among 87 (77.7%) episodes and three were found among 25 (22.3%) episodes. A history of hospitalization within 90 days was an independent risk factor for polymicrobial BSIs (p = 0.003). Intraabdominal infection (p < 0.001) and respiratory tract infection (p = 0.017) were more likely to be associated with polymicrobial BSIs. Gram-negative and Gram-positive bacteria were documented in 95.5 and 46.4% episodes of polymicrobial BSIs, respectively. Inappropriate antimicrobial treatment was observed in 53.6% of polymicrobial BSIs, but only accounted for 23.8% of monomicrobial BSIs (p < 0.001). The overall 30-day mortality rate of the polymicrobial group was significantly higher than those with monomicrobial BSIs (30.3 and 11.6%, respectively; p < 0.001). CONCLUSIONS Patients with polymicrobial BSIs had a high mortality rate. Acknowledgment of the clinical and microbiologic characteristics and recognition of patients at risk for polymicrobial BSIs are critical in EDs.

Human spotted fever group rickettsioses are underappreciated in southern Taiwan, particularly for the species closely-related to Rickettsia felis.

Background Despite increased identification of spotted fever group rickettsioses (SFGR) in animals and arthropods, human SFGR are poorly characterized in Taiwan. Methods Patients with suspected Q fever, scrub typhus, murine typhus, leptospirosis, and dengue fever from April 2004 to December 2009 were retrospectively investigated for SFGR antibodies (Abs). Sera were screened for Rickettsia rickettsii Abs by indirect immunofluorescence antibody assay (IFA), and those with positive results were further examined for Abs against R. rickettsii, R. typhi, R. felis, R. conorii, and R. japonica using micro-immunofluorescence (MIF) tests. Polymerase chain reaction (PCR) for detection of SFGR DNA was applied in those indicated acute infections. Case geographic distribution was made by the geographic information system software. Results A total of 413 cases with paired serum, including 90 cases of Q fever, 47 cases of scrub typhus, 12 cases of murine typhus, 6 cases of leptospirosis, 3 cases of dengue fever, and 255 cases of unknown febrile diseases were investigated. Using IFA tests, a total of 49 cases with 47 (11.4%) and 4 (1.0%) cases had sera potentially positive for R. rickettsii IgG and IgM, respectively. In the 49 cases screened from IFA, MIF tests revealed that there were 5 cases of acute infections (3 possible R. felis and 2 undetermined SFGR) and 13 cases of past infections (3 possible R. felis and 10 undetermined SFGR). None of the 5 cases of acute infection had detectable SFGR DNA in the blood specimen by PCR. Possible acute infection of R. felis was identified in both one case of Q fever and scrub typhus. The geographic distribution of SFGR cases is similar with that of scrub typhus. Conclusions Human SFGR exist and are neglected diseases in southern Taiwan, particularly for the species closely-related to R. felis.

Fever of unknown origin from a left atrial myxoma: an immunologic basis and cytokine association.

Myxoma is the most common primary tumor of the heart. The typical presentations include a triad of embolic phenomena, intracardiac flow obstruction, and constitutional symptoms. We report a case of cardiac myxoma presenting as prolonged fever. Leukocytosis with a left shift, anemia, and elevated C-reactive protein were noted. A large left atrial myxoma was found incidentally by chest computed tomography. The fever subsided after surgical removal of the myxoma. His elevated serum interleukin-4 (IL-4), IL-6, IL-12 p70, interferon-γ, and tumor necrosis factor-α returned to undetectable levels four days after surgery. Cardiac myxomas should be included in the differential diagnosis of prolonged fever, even though no typical symptoms could be found.

Endometriosis Presenting as Bloody Ascites and Shock

Endometriosis is defined as the presence of ectopic foci of endometrial tissue outside the uterine cavity. Many patients are asymptomatic, but others present protean symptoms, including headache, cyclic hemoptysis, pleural effusion, and ascites depending on the endometrial implantation sites. Although massive ascites has been reported as a manifestation of endometriosis, hypovolemic shock is unusual. We report a case of endometriosis presenting as shock and bloody ascites to show that endometriosis can result in acute abdomen with shock. A 29-year-old female presented to our Emergency Department (ED) complaining of light-headedness and palpitations. Examination suggested hypovolemic shock. Ultrasonography revealed massive ascites and paracentesis showed bloody ascites. Exploratory laparoscopy showed endometriosis over the left broad ligament. After fluid resuscitation and electrocauterization of the endometriosis, the patients condition stabilized, and she was discharged 5 days after admission. This case is presented to raise awareness that endometriosis can present with hypovolemic shock.