Infections caused by Scedosporium spp

Scedosporium spp. are increasingly recognized as causes of resistant life-threatening infections in immunocompromised patients. Scedosporium spp. also cause a wide spectrum of conditions, including mycetoma, saprobic involvement and colonization of the airways, sinopulmonary infections, extrapulmonary localized infections, and disseminated infections. Invasive scedosporium infections are also associated with central nervous infection following near-drowning accidents. The most common sites of infection are the lungs, sinuses, bones, joints, eyes, and brain. Scedosporium apiospermum and Scedosporium prolificans are the two principal medically important species of this genus. Pseudallescheria boydii, the teleomorph of S. apiospermum, is recognized by the presence of cleistothecia. Recent advances in molecular taxonomy have advanced the understanding of the genus Scedosporium and have demonstrated a wider range of species than heretofore recognized. Studies of the pathogenesis of and immune response to Scedosporium spp. underscore the importance of innate host defenses in protection against these organisms. Microbiological diagnosis of Scedosporium spp. currently depends upon culture and morphological characterization. Molecular tools for clinical microbiological detection of Scedosporium spp. are currently investigational. Infections caused by S. apiospermum and P. boydii in patients and animals may respond to antifungal triazoles. By comparison, infections caused by S. prolificans seldom respond to medical therapy alone. Surgery and reversal of immunosuppression may be the only effective therapeutic options for infections caused by S. prolificans.     

Infections caused by unusual Methylobacterium species

We describe six patients with hospital-acquired bacteremia caused by Methylobacterium species, including M. radiotolerans (n = 2), M. thiocyanatum (n = 2), M. aminovorans (n = 1), and M. lusitanum (n = 1), which were confirmed to species level by 16S rRNA gene sequence analysis. Among these patients, five had catheter-related bacteremia and all had favorable outcomes.     

Incidence and characteristics of urinary tract infections caused byCorynebacterium urealyticum (Corynebacterium group D2)

The incidence and characteristics of urinary tract infections caused byCorynebacterium urealyticum were studied prospectively in 20,766 urine samples.Corynebacterium urealyticum was isolated from 67 samples (0.32 %). Twenty-four percent of the patients from whomCorynebacterium urealyticum was isolated showed mild symptoms and had no risk factors other than prolonged hospitalization and previous antibiotic treatment. Sixty percent of the patients had urinary tract-related symptoms. The main risk factors were underlying urinary tract disease, antibiotic treatment, prolonged hospitalization and urological manipulation. Patients with antimicrobial treatment had a favourable clinical course, with the exception of two patients with encrusted cystitis.     

Infections caused by Klebsiella ozaenae: a changing disease spectrum.

A total of 64 isolates of Klebsiella ozaenae were recovered from 36 patients during a 40-month period. Over 7,500 isolates of K. pneumoniae were isolated during the same time period. Before this decade, K. ozaenae was considered to be only a colonizer of the nasopharynx or a putative cause of ozena (atrophic rhinitis). K. ozaenae was recovered most frequently from sputum in mixed culture but was associated with infection in 12 patients (2 with bacteremia, 3 with urinary tract infection, 1 with soft tissue infection, and 6 with mucopurulent nasal discharge). The spectrum of disease caused by this organism is more extensive than has been appreciated previously.     

Adherence and hemagglutination ofCorynebacterium group D2

Sixty-one strains ofCorynebacterium group D2 were examined for their ability to adhere to human uroepithelial cells and to agglutinate human and guinea-pig erythrocytes. Strains were isolated from samples of two origins: urine of bacteriuric patients and healthy skin of patients without urinary infection. In addition, the isolates were examined by scanning and transmission electron microscopy. Heavy adherence to the uroepithelial cells but weak hemagglutination were noted. No statistical association was demonstrated between the adherence and the origin of the strains (65.2 % of urinary isolates and 80 % of healthy skin isolates were adherent). On transmission electron microscopy, a close association was observed between adherent bacteria and cells on thin sections and only few strains were piliated with negative staining. These results do not support a role of adherence as a predictor of pathogenicity ofCorynebacterium group D2 which seems to act as an opportunistic pathogen in urinary tract infections.     

Endocarditis caused by nonhemolytic group B streptococcus.

We report a case of bacterial endocarditis caused by nonhemolytic group B streptococcus (GBS) in a 67-year-old man with no predisposing risk factors. Nonhemolytic GBS strains rarely cause illness and are usually detected in perinatal infections. We believe this to be the first reported case of endocarditis caused by a nonhemolytic strain of GBS.     

Serious infection caused by group C streptococci.

Group C streptococci commonly cause infection in animals but only occasionally give rise to severe infection in man. We report here three cases of serious human infection due to this organism and discuss its pathogenicity in relation to the clinical manifestations of the disease.     

Cavitating pneumonia caused by Corynebacterium group JK.

Corynebacterium group JK organisms were isolated from lung fluid aspirated with a fine needle from one of four thick-walled cavitary lesions in a 72-year-old female. Cultures and stains for mycobacteria and fungi were negative. The patient was successfully treated with an 8-week course of vancomycin.     

RhD免疫性溶血产前诊断与治疗的研究

目的探讨应用荧光定量PCR方法对Rh阴性孕妇血浆中游离胎儿DNA;进行无创性产前诊断胎儿RhD血型及应用血浆置换疗法配合药物治疗孕妇及胎儿Rh(D)血型不合的免疫性溶血病的疗效,预防孕妇早孕自然流产或不足月死胎。方法产前采用荧光定量PCR技术产前检测胎儿RhD血型,分娩后用血清学方法证实。对照组14例用药物治疗孕妇及胎儿Rh(D)血型不合者,实验组15例用血浆置换配合药物治疗对孕妇及胎儿Rh(D)血型不合者进行治疗,观察IgG抗-D抗体效价以及新生儿直接抗人球蛋白试验、游离IgG抗-D抗体、放散试验,胆红素。结果产前荧光定量PCR与产后血清学法Rh(D)血型结果一致。对照组14例孕妇孕期血浆抗体滴度为1∶32～1∶256;实验组15例孕妇PE 2～5次/例,血浆置换前后血浆抗体滴度分别为1∶(96±43.6)、1∶(18±14.7),二者比较有显著统计学差异(t=6.77,P<0.01)。对照组10例发生新生儿溶血病,实验组4例发生新生儿溶血病。对照组10例直接抗人球蛋白试验、游离IgG抗-D抗体、放散试验均阳性,血清胆红素:(84.2～205)μmol/L,平均(154.6±46)μmol/L;实验组4例直接抗人球蛋白试验、游离IgG抗-D抗体、放散试验阳性,血清胆红素:38.3μmol/L～141.2μmol/L,平均(76.5±36)μmol/L。结论应用荧光定量PCR方法进行无创性胎儿RhD血型检测可用于新生儿溶血病的预防和诊断;血浆置换配合药物治疗孕妇及胎儿RhD血型不合的免疫性溶血病的疗效优于单纯药物治疗,值得临床推广应用。     

Infections caused by Aeromonas species in hospitalized patients: A case series

The Aeromonads are ubiquitous Gram-negative bacilli that cause community acquired, and healthcare associated infections. In this retrospective study we analysed clinical and microbiological characteristics of thirty-six culture proven Aeromonas infections. The most common species isolated was A.hydrophila. Clinical presentation included syndromes like skin and soft tissue infections (SSTI), urinary tract infections, and central line associated bloodstream infections (CLABSI). Most of the isolates were sensitive to aminoglycosides [97.2%], followed by 3 rd generation cephalosporins, quinolones and carbapenems. Overall mortality was 13.88% (5 out of 36 patients). A high index of suspicion is required for diagnosis and better outcomes.     

Isolation ofCorynebacterium group D2 from clinical specimens

A total of 38 strains ofCorynebacterium Group D2 isolated from clinical specimens in Belgian laboratories were characterized by pronounced urease activity, inability to acidify sugars and to reduce nitrates and multiresistance to antibiotics. Two strains were involved in clinical diseases. The organisms were found to have a more opportunistic than pathogenic behaviour.     

Rapid diagnosis of pharyngitis caused by group A streptococci

Although commercial rapid antigen detection tests (RADTs) are more expensive than blood agar plate (BAP) cultures, the advantage they offer is the speed with which they provide results. Rapid identification and consequent prompt treatment of patients with pharyngitis due to group A beta-hemolytic streptococci (GABHS) can reduce the risk of spread of GABHS, can allow patients to return to school or work sooner, and may reduce the acute morbidity of this illness. In most studies, RADTs have been compared with BAP cultures as the criterion standard. However, these comparisons are complicated by the fact that there is no universally accepted procedure for performing a BAP culture. The great majority of the RADTs that are currently available have a high specificity (i.e., 95% or greater) and a sensitivity of between 70 and 90% compared with BAP cultures. Few published studies have compared the performance of various RADTs to each other or examined the performance of various RADTs in the office setting. There is also relatively little published information about how physicians in practice actually use RADTs, but the available information suggests that many physicians do not follow recommended guidelines. While the development of easy-to-perform RADTs for the diagnosis of GABHS pharyngitis has altered clinical practice substantially, only limited data about cost-effectiveness are currently available.     

An outbreak of gastroenteritis during school trip caused by serotype G2 group A rotavirus

Between May14 and 18, 2001, there was an outbreak of acute gastroenteritis involving 45 school children out of a total of 107 (aged 11-12 years) attending a 3-day school trip. The epidemic curve characterized by a rapid onset and decline with a single peak incidence over a 5-day period resembled the pattern typical of a food-borne gastroenteritis outbreak. Epidemiological and virological investigations concluded, however, that this outbreak was caused by a single strain of serotype G2 group A rotavirus spreading to schoolmates from the primary case-pupil who had already been ill at the start of the trip. Efficient person-to-person transmission was likely to have occurred due to prolonged and close contacts under the conditions typical of such school trips. This study emphasizes the importance of including group A rotavirus infection as a possible cause of gastroenteritis outbreaks even in older children and adults.