Corynebacterium propinquum as the first cause of infective endocarditis in childhood

We here present a 7-year-old girl with ventricular septum defect and ventriculoatrial communication, who developed infective endocarditis (IE) due to Corynebacterium propinquum in the tricuspid valve. The patient was admitted because of an 8-day history of fever. Transthoracic echocardiogram showed non-pedunculated vegetation on the septal leaflet of the tricuspid valve. Gram-positive coryneform bacteria grew from three consecutive sets of blood cultures taken on admission. C. propinquum was confirmed by 3 microbiological approaches; (i) biochemical testing using API Coryne panels, (ii) a sequence-based method using the 16S rRNA gene and partial rpoB sequencing, and (iii) matrix-assisted laser desorption ionization–time of flight mass spectrometry. The isolates were susceptible to a wide variety of β-lactams and vancomycin. The patient was successfully treated with antimicrobial agents without surgical intervention. There have only been available of clinical details of two adult cases of invasive C. propinquum infections; one of which was presented as IE, and the other was pleuritis in a patient with lung cancer. To the best of our knowledge, this is the first report to describe C. propinquum as a cause of IE as well as that of invasive infections in a pediatric population. Multiple methods that reliably differentiated related species helped us to establish this rare organism. Our report expanded the clinical spectrum of C. propinquum infections.     

Multiple skin abscesses associated with bacteremia caused by Burkholderia gladioli: A case report

BACKGROUND Burkholderia gladioli (B. gladioli) is regarded as a rare opportunistic pathogen. Only a few patients with abscesses caused by B. gladioli infections have been reported, and these are usually abscesses at the incision caused by traumatic surgery.CASE SUMMARYA 74-year-old male patient with abscesses and pain throughout his body for 1 mo was admitted to our hospital. Some of the abscesses had ruptured with purulent secretions on admission. Color Doppler ultrasound examination of the body surface masses showed mixed masses 75 mm × 19 mm, 58 mm × 17 mm, 17 mm × 7 mm, and 33 mm × 17 mm in size in the muscle tissues of both the right and left forearms, the posterior area of the right knee and the left leg, respectively. Abscess secretions and blood cultures grew B. gladioli. The following 3 methods were used to jointly identify the bacterium: an automatic microbial identification system, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, and full-length 16S rDNA sequencing. After 27 d of treatment with meropenem, etimicin, trimethoprim-sulfamethoxazole and other antibiotics, most of his skin abscesses were flat and he was discharged without any symptoms.CONCLUSIONThis is the first reported case of multiple skin abscesses associated with bacteremia caused by B. gladioli. Our study provides important reference values for the clinical diagnosis and treatment of B. gladioli infections.     

Bordetella holmesii infection: current knowledge and a vision for future research

Bordetella holmesii is a recently recognized Gram-negative bacterium causing both pertussis-like respiratory symptoms and invasive infections, such as bacteremia, pneumonia, meningitis, arthritis, pericarditis and endocarditis. Few data are available on its epidemiological characteristics, mostly related to respiratory infections. However, these are frequently misdiagnosed as a Bordetella pertussis infection as most diagnostic tests routinely used are not species-specific, thus biasing the epidemiological studies of both strains, as well as the efficacy studies on pertussis vaccination. There is no accepted agreement on treatment and it remains unknown if antimicrobial prophylaxis is indicated in certain clinical settings. We review here the current knowledge on B. holmesii and the need for further research.     

Bilateral Candida endophthalmitis accompanying Candida lusitaniae bloodstream infection: A case report

Candida lusitaniae is an uncommon cause of candidiasis in humans. Ocular manifestations of C. lusitaniae infection have not been reported. C. lusitaniae is either intrinsically resistant to amphotericin B or can acquire such resistance. We describe a case of bilateral endophthalmitis due to C. lusitaniae bloodstream infection in a liver transplant patient with rectal cancer. The patient suffered fungemia and endophthalmitis and was treated with liposomal amphotericin B. The isolate was identified as C. lusitaniae by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, the system based on biochemical tests, and sequencing of the internal transcribed spacer region. The minimal inhibitory concentrations were 0.06 μg/mL for amphotericin B and 2.0 μg/mL for fluconazole. Repeat blood cultures were negative and the endophthalmitis improved following treatment with liposomal amphotericin B. However, the treatment was changed to fluconazole due to nephrotoxicity. No recurrence occurred after completion of treatment.     

Lactococcus lactis cholangitis and bacteremia identified by MALDI-TOF mass spectrometry: A case report and review of the literature on Lactococcus lactis infection

Lactococcus lactis is a rare causative organism in humans. Cases of L. lactis infection have only rarely been reported. However, because it is often difficult to identify by conventional commercially available methods, its incidence may be underestimated. We herein report the case of a 70-year-old man with cholangiocarcinoma who developed L. lactis cholangitis and review previously reported cases of L. lactis infection. Our case was confirmed by matrix-assisted desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). This case shows L. lactis is a potential causative pathogen of cholangitis and that MALDI-TOF MS can be useful for the rapid and accurate identification of L. lactis infection. We searched the literature for published case reports on cholangitis and any other infections caused by L. lactis, and thereby identified 36 cases, including our case. At least 66.7% (n = 24) of the cases had significant underlying conditions; 15 of the cases involved patients with an immunocompromised status. At least 41.7% (n = 15) had a significant food consumption history, such as the consumption of unpasteurized dairy products. The clinical sources of L. lactis were diverse and endocarditis was the most common diagnosis (n = 8), followed by hepatobiliary infection (n = 6), central nervous system infection (n = 5), and peritonitis (n = 4). The prognosis was favorable in most cases.     

First report of a Wautersiella falsenii isolated from the urine of an infant with pyelonephritis

Here, we report the first isolation of Wautersiella falsenii from the urine of an infant with a complicated urinary tract infection. W. falsenii was correctly identified by matrix-assisted laser desorption ionisation time of flight mass spectrometry. The identification was confirmed by 16S polymerase chain reaction. Susceptibility test results of this isolate are reported. Ciprofloxacin treatment resulted in clinical and microbiological improvement.     

Early adjustment of empirical antibiotic therapy of bloodstream infections on the basis of direct identification of bacteria by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and Gram staining results

IntroductionTo assess the potential added value of rapid MALDI-TOF MS-based identification of bacteria in positive blood cultures to the information provided by Gram staining for adequate empirical antibiotic treatment adjustments in patients with bloodstream infections (BSI).MethodsWe conducted a retrospective, single-center, pre-post quasi-experimental study. In the pre-MALDI-TOF MS phase of the study antibiotic adjustments were made on the basis of Gram stain results, whereas in the MALDI-TOF MS phase they were based on information provided by Gram staining and MALDI-TOF MS results. No antimicrobial stewardship program for BSI was in place within the study period. Antibiotic regimens were categorized as correct, improvable or incorrect.ResultsCohorts were matched for demographics, clinical characteristics of patients and bacterial species involved. Enterobacteriales were the most represented in both study periods (67%), followed by Non-fermenting Gram-negative bacilli and Gram-positive cocci. The number of patients receiving correct, improvable and incorrect empirical antibiotic treatments was comparable for both study periods (P = 0.45, P = 0.57, P = 0.87, respectively). The percentage of patients who ended up receiving correct treatment following modified empirical antibiotic regimens was significantly higher (P = 0.008) in the MALDI-TOF MS phase (27 patients/38.6%) than in the pre-MALDI-TOF MS phase of the study (11 patients/15.7%), although overall adequate coverage of the bacteria causing the infection was comparable across the study periods (90%).ConclusionGram stain results offer valuable information for early adjustment of empirical antibiotic therapies for BSI. Nevertheless, rapid identification of bacteria involved in BSI by MALDI-TOF MS provides added value to achieve this aim.     

MALDI-TOF MS直接鉴定血培养阳性病原的临床应用

目的 了解基质辅助激光解吸电离飞行时间质谱(MALDI-TOF MS)直接快速检测血培养报阳样本的可行性.方法 收集同济大学附属同济医院报阳血培养样本682例,从血培养瓶直接抽取血液至分离胶采血管离心富集细菌后,采用MALDI-TOF MS进行直接鉴定(快速质谱法).同时对报阳血培养标本进行涂片镜检及转种培养后,分别采...     

Increased copy number of 23S ribosomal RNA gene with point mutation in MRSA associated with linezolid resistance in a patient treated with long-term linezolid

BackgroundMethicillin-resistant Staphylococcus aureus (MRSA) infection is one of the most difficult infections we have to treat. Linezolid is one of the effective treatment options for refractory MRSA infections. There are cases where we are forced to use long-term linezolid treatment for refractory MRSA infections.ObjectiveTo discuss the evolution of Linezolid resistance factors in clinical isolates of MRSA.MethodsWe investigated 16 MRSA isolated from a patient treated with linezolid for a long period of 75 days. We performed antibiotic susceptibility test, 23S rRNA genes sequencing analysis, Pulsed-field gel electrophoresis.ResultsMRSA isolates were susceptible to linezolid before the start of treatment, but became less susceptible by prolonged treatment. The 23S rRNA sequencing analysis of linezolid-resistant strains that appeared 17 days after the start of treatment with linezolid revealed that all resistant MRSA had the G2576T substitution (Escherichia coli 23S rRNA gene number). The number of copies of this mutation increased with the use of linezolid.ConclusionLong-term use of linezolid in a patient or reuse of linezolid in a patient who has been previously treated with linezolid can lead to the emerging of linezolid-resistant MRSA in the host.     

嗜麦芽寡氧单胞菌临床株与环境株的16S rRNA基因序列及系统发育分析

目的:比较嗜麦芽寡氧单胞菌临床株与环境株16S rRNA基因序列,构建系统发育树,分析其进化关系.方法:对选取的3株嗜麦芽寡养单胞菌临床株和1株环境株的16S rRNA基因进行PCR扩增并测序.将上述及从GenBank中挑选出的其他32株不同来源的嗜麦芽寡养单胞菌的16S rRNA基因序列进行对比分析.并绘制系统发育树.结果:系统发育分析表明大部分菌株可根据来源分为3个簇,序列分析显示某些高度可变区可能存在可区分临床株与环境株的关键序列.结论:嗜麦芽寡养单胞菌基因型及表现型具有多样性:大部分嗜麦芽寡氧单胞菌临床株与环境株可根据16S rRNA基因序列进行鉴别.     

Comparative study of bacterial flora in bronchoalveolar lavage fluid of pneumonia patients based on their pneumonia subtypes and comorbidities using 16S ribosomal RNA gene analysis

IntroductionThe culture method is the gold standard for identifying pathogenic bacteria in patients with pneumonia but often does not reflect the exact bacterial flora in pulmonary lesions of pneumonia, partly owing to easiness or difficulties in culturing certain bacterial species. We aimed to evaluate bacterial flora in bronchoalveolar lavage fluid (BALF) samples directly obtained from pneumonia lesions using 16S ribosomal RNA (rRNA) gene analysis to compare the results of the BALF culture method in each category of pneumonia.MethodsBacterial florae were detected by a combination of the culture method, and the clone library method using the 16S rRNA gene sequencing in BALF directly obtained from pneumonia lesions in pneumonia patients from April 2010 to March 2020 at the University of Occupational and Environmental Health, Japan, and affiliated hospitals. Clinical information of these patients was also collected, and lung microbiome was evaluated for each pneumonia category.ResultsAmong 294 pneumonia patients (120 with community-acquired pneumonia (CAP), 101 with healthcare-associated pneumonia (HCAP), and 73 with hospital-acquired pneumonia (HAP)), significantly higher percentages of obligate anaerobes were detected in CAP than in HCAP and HAP patients by the clone library method. Corynebacterium species were significantly highly detected in HAP patients and patients with cerebrovascular diseases than in patients without, and Streptococcus pneumoniae was frequently detected in patients with diabetes mellitus.ConclusionObligate anaerobes may be underestimated in patients with CAP. Corynebacterium species should be regarded as the causative bacteria for pneumonia in patients with HAP and cerebrovascular diseases.     

Comparison of the ASTA MicroIDSys and VITEK MS matrix-assisted laser desorption/ionization time-of-flight mass spectrometry systems for identification of clinical bacteria and yeasts

The ASTA MicroIDSys system (ASTA, Suwon, Korea) is a newly developed Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) system for identification of microorganisms. We compared the performance of the ASTA MicroIDSys system with that of the VITEK MS system (bioMérieux, Marcy l’Etoile, France) for identifying clinical microorganisms. A total 2055 isolates including 1910 bacteria and 145 yeasts were tested. Among them, the VITEK MS correctly identified 1999 (97.3%) isolates to species level and 26 (1.3%) to the genus level. The ASTA MicroIDSys correctly identified 1988 (96.7%) isolates to species level and 28 (1.4%) to the genus level. The VITEK MS and ASTA MicroIDSys misidentified one isolate and four (0.2%) isolates, respectively, and provided no identification for 29 (1.4%) and 35 (1.7%) isolates, respectively. The performance of the ASTA MicroIDSys was comparable to that of the VITEK MS for identification of clinically relevant bacterial and yeast isolates.     

慢性前列腺炎患者前列腺液细菌16SrRNA基因的检测

目的通过采用聚合酶链反应（PCR）技术对慢性前列腺炎患者前列腺液中细菌16SrRNA基因检测,探讨PCR方法诊断慢性前列腺炎细菌学病因的价值。方法收集102例慢性前列腺炎患者的前列腺液进行细菌培养,同时采用PCR法检测前列腺液中细菌16SrRNA基因,并测定和分析所得片段的DNA序列。对培养结果与PCR法检测结果进行了比较。结果102份前列腺液标本中,细菌培养法18例阳性,84例阴性,阳性率17．7％;PCR法71例阳性,31例阴性,阳性率69．6％。细菌培养法与PCR法检测结果比较,其差异有统计学意义（P〈0．05）。测序结果显示DNA序列与GenBank公布的16SrRNA基因序列具有很高的同源性。结论PCR技术对慢性前列腺炎的临床诊断具有重要意义。     

HPV感染及高级别CIN患者阴道微生态研究

目的分析人乳头瘤病毒16、18(HPV16、18)宫颈感染及高级别宫颈上皮内瘤变(CIN)患者阴道微生态特征。方法以3例湿疣样变或CIN1级HPV16和/或18感染患者为低级别CIN组,以5例高级别CIN病变HPV16和/或18感染患者为高级别CIN组,以3例HPV阴性阴道炎患者为对照组,采用16S rRNA基因扩增技术分析各研究组患者阴道微生物菌群组成,采用分层聚类法分析并比较各研究组阴道微生物菌群分布特征。结果高级别CIN组阴道微生物细菌种类多样性及复杂性较低级别CIN组、对照组更为明显;从对照组、低级别CIN组至高级别CIN组,卷曲乳杆菌和穹隆乳杆菌丰度呈下降趋势,惰性乳杆菌丰度呈增加趋势;定植菌犬布鲁氏菌丰度呈下降趋势,致病菌戴阿李斯特琥珀酸纤毛杆菌、阴道加德纳菌和短普雷沃菌丰度呈上升趋势。结论高级别CIN患者阴道菌种结构复杂性、多样性明显。阴道乳杆菌种类和丰度对阴道健康起重要作用,惰性乳杆菌则具有相反作用。犬布鲁氏菌、戴阿李斯特琥珀酸纤毛杆菌、阴道加德纳菌和短普雷沃菌长期存在于阴道,与HPV持续感染、进展至高级别CIN病变密切相关。     

Streptomyces pneumonia in an immunocompetent patient: a case report and literature review

We describe a case of Streptomyces lanatus pneumonia in an immunocompetent 52-year-old woman. Bronchoalveolar lavage culture grew Streptomyces, which was identified by 16S rRNA sequencing. The infection resolved completely after successful treatment with doxycycline for 6 months. We also review the literature on human invasive Streptomyces infections.     

Cholangitis with Sphingobacterium multivorum and Acinetobacter junii bacteremia in a patient with gastric cancer: A case report

IntroductionSphingobacterium is an aerobic, glucose non-fermenting, Gram-negative rod bacterium that has been isolated from soil, plants, food, and water sources, including in hospitals. Reports of systemic infections caused by Sphingobacterium multivorum (S. multivorum) are rare, and their clinical and microbiological characteristics remain unclear. Moreover, conventional microbiological methods have limited ability to identify S. multivorum. We report the first case of obstructive cholangitis with bacteremia caused by S. multivorum in a patient with gastric cancer.Case reportA 68-year-old woman with advanced gastric cancer, hypertension, and hyperlipidemia was admitted with obstructive jaundice, and subsequently developed obstructive cholangitis during the hospital stay. S. multivorum were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and 16S ribosomal RNA sequencing of the patient's blood samples. Based on the antibiotic susceptibility results of the isolates, cefepime was administered intravenously for 14 days, with good therapeutic outcomes.ConclusionsS. multivorum infection is rare, and its microbiology and pathogenicity in humans is mostly unknown. Therefore, multiple diagnostic approaches should be used to identify S. multivorum, and antimicrobial therapy should be selected based on the in vitro susceptibility. This report provides clinicians with novel information on the clinical manifestations and diagnostic methods for an accurate diagnosis of S. multivorum.     

慢性前列腺炎患者前列腺液细菌16S rRNA基因的检测

目的通过采用聚合酶链反应(PCR)技术对慢性前列腺炎患者前列腺液中细菌16S rRNA基因检测,探讨PCR方法诊断慢性前列腺炎细菌学病因的价值。方法收集102例慢性前列腺炎患者的前列腺液进行细菌培养,同时采用PCR法检测前列腺液中细菌16S rRNA基因,并测定和分析所得片段的DNA序列。对培养结果与PCR法检测结果进行了比较。结果102份前列腺液标本中,细菌培养法18例阳性,84例阴性,阳性率17.7%;PCR法71例阳性,31例阴性,阳性率69.6%。细菌培养法与PCR法检测结果比较,其差异有统计学意义(P<0.05)。测序结果显示DNA序列与GenBank公布的16S rRNA基因序列具有很高的同源性。结论PCR技术对慢性前列腺炎的临床诊断具有重要意义。     

人源猪链球菌19株分离鉴定及毒力基因检测

目的检测广西右江民族医学院附属医院2015-2019年临床分离的猪链球菌对常用抗生素耐药性及毒力基因,了解该地区猪链球菌对常用抗生素耐药性及分子流行病学特征。方法收集2015-2019年临床分离的猪链球菌19株,采用基质辅助激光解吸电离飞行时间质谱(MALDI-TOF MS)技术对其进行鉴定,参照CLSI推荐的微量肉汤稀释法测定猪链球菌对常用8种抗生素的敏感性,同时检测其种特异性基因16S rDNA及cps2J、mrp、ef、orf2、fbps、gapdh 6个毒力基因携带情况。结果19株菌株经MALDI-TOF MS鉴定均为猪链球菌,鉴定正确率均在99%以上。药敏试验结果显示这19株菌株对青霉素的敏感率为68.5%,对氨苄西林、头孢吡肟、头孢噻肟、头孢曲松和万古霉素均100%敏感,对红霉素和克林霉素100%耐药。毒力基因检测结果显示该地区流行的猪链球菌主要基因型以cps2J、mrp、ef、orf2、fbps、gapdh型为主。所有的分离株均携带了ef和fbps毒力基因。结论及时掌握该地区致病性猪链球菌对常用抗生素的耐药性及其毒力因子的流行病学,对于预防和控制大规模暴发猪链球菌感染具有参考意义。