Chung-Hsu Lai

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.

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.

Pseudomonas mendocina spondylodiscitis : A case report and literature review

Pseudomonas mendocina is rarely recovered as a human pathogen. Only 2 human cases have been reported in the literature. Here, we report the third human case and possibly the first 1 to involve spinal infection caused by such an unusual bacterium.

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.

Clinical significance of Acinetobacter species isolated from cerebrospinal fluid

Medical records of 54 patients whose cerebrospinal fluid (CSF) cultures were positive for Acinetobacter were retrospectively reviewed. In 34 (63.0%) patients, the Acinetobacter isolates were clinically insignificant. In the other 20 (37.0%) patients, presence of the organism was regarded as clinically significant and specific antimicrobial therapy was administered. Patients with clinically significant Acinetobacter in CSF more frequently resided in intensive care units (p = 0.011), had intracerebral hemorrhage (p = 0.012) or previous CNS infection (p = 0.003), had prior antibiotic exposure (p = 0.011), and had undergone neurosurgical procedures (p = 0.003). Their CSF was characteristic of neutrophilic pleocytosis, an elevated protein level, and a low CSF-to-serum glucose ratio. Apart from fever, no significant statistical differences existed in individual clinical symptoms and signs between the 2 groups of patients, while a combination of symptoms efficiently differentiated clinically significant and insignificant Acinetobacter. The finding of multiple CSF specimens positive for Acinetobacter was highly suggestive of an active CNS infection (p<0.001). The high ratio of clinically insignificant Acinetobacter CSF isolates highlights the importance of careful judgment when the organism is cultured from CSF. Antimicrobial therapy must be initiated promptly in patients with identified risk factors, while unnecessary treatment should be avoided in those without them.

Acute acalculous cholecystitis: A rare presentation of typhoid fever in adults

Adult typhoidal acute acalculous cholecystitis is rare with only 2 cases having been reported in the English literature. We present the case of a previously healthy 36-y-old female who suffered fever, chills, epigastralgia and progressive jaundice for 3 d, with acute acalculous cholecystitis subsequently diagnosed. In addition to antibiotic therapy with ceftriaxone, open cholecystectomy was performed. However, bile and blood culture both showed Salmonella typhi growth unexpectedly, and ileocolitis was revealed by colonoscopy. Careful tracing of the history of the patient recalled a history of travel to Indonesia. In adults without common risk factors for acalculous cholecystitis, a detailed history including travel to endemic areas and high index of suspicion for typhoidal acute acalculous cholecystitis are important, and appropriate antimicrobial therapy for covering Salmonella typhi should be considered.

Acute Q Fever Hepatitis in Patients with and without Underlying Hepatitis B or C Virus Infection

BACKGROUND Although hepatitis is one of the major presentations of acute Q fever, the possible influence of viral hepatitis in Q fever has, to our knowledge, never been investigated. It is an important issue in regions where Q fever hepatitis and viral hepatitis are prevalent, such as Taiwan. We conducted a study to investigate the possible influence of viral hepatitis in cases of acute Q fever hepatitis. METHODS Cases of acute Q fever confirmed by serologic examination were included in the study. All patients who were found to be positive for Q fever were tested for hepatitis B surface antigen and antibody to hepatitis C virus, and those with positive results had their viral loads determined. Demographic data, clinical manifestations, results of laboratory and imaging examinations, and responses to treatment were recorded retrospectively from charts. RESULTS A total of 58 patients with acute Q fever hepatitis were studied, of whom 16 (27.6%) had viral hepatitis (hepatitis B virus infection in 12 and hepatitis C virus infection in 4). Patients with and patients without viral hepatitis did not differ with regard to clinical manifestations and responses to treatment, except that chills (100% vs. 73.8%; P=.02) and nausea and/or vomiting (18.8% vs. 2.4%; P=.03) were significantly more common among patients with viral hepatitis. The change in hepatitis B and C virus loads between the acute and convalescent phase was <1.0 log(10). CONCLUSIONS The clinical manifestations of acute Q fever hepatitis differ little in patients with and patients without underlying viral hepatitis, and replication of hepatitis virus is not influenced by acute Q fever hepatitis.