Blood culture bottles for culturing cerebrospinal fluid in cases of bacterial meningitis caused by Enterococcus faecalis: A case report.

Pathogen identification is essential for the treatment of bacterial meningitis. However, cerebrospinal fluid (CSF) culture tests are often negative when antimicrobial agents are administered before CSF is collected. Therefore, it is necessary to improve the culturing process for such samples. Here, we report a case of bacterial meningitis where the causative bacteria were detected by inoculating that patient's CSF samples into blood culture bottles. A 52-year-old man developed a fever and headache after undergoing transnasal transsphenoidal surgery for a nonfunctioning pituitary neuroendocrine tumor. He was suspected of having a wound infection, for which he was treated with cefozopran and vancomycin. A CSF test was also performed, owing to persistent fever, and bacterial meningitis was suspected. Although conventional CSF culture tests were negative, CSF cultures using blood culture bottles detected Enterococcus faecalis. The antimicrobial agents were therefore changed to ampicillin and gentamicin, after which the patient's meningitis improved. The blood culture bottles used contained adsorbed polymer beads with antimicrobial neutralizing properties, which likely contributed to the isolation of the bacteria. In addition to conventional cultures, ones done in blood culture bottles may be useful for diagnosing bacterial meningitis via CSF samples-particularly in cases where antimicrobial agents have already been administered.

Clinical characteristics of Actinotignum schaalii bacteremia in a Japanese tertiary hospital.

We retrospectively analyzed seven patients with Actinotignum schaalii bacteremia in a tertiary hospital in Japan. Pyelonephritis was the most frequent source of bacteremia, followed by Fournier's gangrene and pyometra. All patients with pyelonephritis had underlying urological conditions, ureteral stents, nephrostomy, ureteral stones, or ureterocele.

Indwelling catheterization, renal stones, and hydronephrosis are risk factors for symptomatic Staphylococcus aureus-related urinary tract infection.

PURPOSE: Staphylococcus aureus is a relatively uncommon causative agent of urinary tract infection (UTI). However, the clinical features of S. aureus-related UTI are unclear. Thus, we aimed to clarify how patients with S. aureus bacteriuria develop UTI and determine the features and clinical risk factors of symptomatic S. aureus-related UTI. METHODS: We performed a retrospective study of patients at the Hiroshima University Hospital for whom S. aureus had been isolated from urine culture from January 2010 to December 2017. The characteristics (age, sex, body mass index, indwelling catheterization, renal stones, hydronephrosis, anticancer drug use, diabetes mellitus, steroid use, serum albumin, antibiotic use in the past 1 month, estimated glomerular filtration rate, benign prostate hyperplasia, and neurogenic bladder) of patients with UTI and those without UTI were compared, and the risk factors for S. aureus-related UTI were identified by multiple logistic regression model. RESULTS: A total of 286 patients with S. aureus bacteriuria were analyzed; 33 patients developed UTI. The causative pathogens were methicillin-sensitive S. aureus and methicillin-resistant S. aureus (MRSA) in 14 and 19 patients, respectively, who developed UTI. This study demonstrated that indwelling catheterization, hydronephrosis, and renal stones are significantly associated with S. aureus-related UTI (p = 0.01, odds ratio = 3.1; and p < 0.01, odds ratio = 7.0; and p = 0.02, odds ratio = 1.2; respectively) and hypoalbuminemia in MRSA-related UTI (p < 0.01). CONCLUSION: Paying attention to risk factors, specifically indwelling catheterization, renal stones, and hydronephrosis, will be an effective strategy for prevention of S. aureus-related UTI with persistent staphylococcal bacteriuria.

Clinical and microbiological characteristics of Eggerthella lenta bacteremia at a Japanese tertiary hospital.

Eggerthella lenta is an important cause of anaerobic bloodstream infections and is associated with high mortality. However, there are few reports of E. lenta infection in Japan. This study aimed to evaluate the clinical and microbiological characteristics of bacteremia caused by E. lenta in Hiroshima, Japan. We retrospectively analyzed E. lenta bacteremia patients at the Hiroshima University Hospital between January 2012 and December 2020. During the study period, 14 patients with E. lenta bacteremia were identified. All E. lenta isolates were cultured in anaerobic bottles, and the median time to blood culture positivity was 52.9 h. In most cases (85.6%), the source of E. lenta bacteremia was associated with intra-abdominal infections, and colon perforation was the most frequent source of E. lenta bacteremia (42.9%, n = 6). Antimicrobial susceptibility testing showed high minimal inhibitory concentrations (MIC) of piperacillin-tazobactam (TZP) and 100% susceptibility to ampicillin-sulbactam, carbapenems, and metronidazole. This study demonstrates that E. lenta bacteremia is associated with intra-abdominal infections, particularly colon perforation, and a high MIC of TZP. When gram-positive anaerobes are detected in the blood cultures of patients with severe intra-abdominal infections, clinicians should suspect E. lenta, and it may be better to change antimicrobial agents from TZP.

[In vitro combined effects of double antibacterial drugs against multidrug-resistant Pseudomonas aeruginosa isolates: comparison among combinations of colistin, arbekacin, aztreonam, rifampicin and piperacillin].

This in vitro study examined the combined effects of double antibacterial drugs against multidrug-resistant Pseudomonas aeruginosa (MDRP). The tested clinical isolates from Hiroshima University Hospital were 40 strains which met the criteria for MDRP, that is, the minimum inhibitory concentration (MIC) was > or = 16 microg/mL of meropenem, > or = 4 microg/mL of ciprofloxacin and > or = 32 microg/mL of amikacin. Using the original checkerboard plates for colistin (CL), arbekacin (ABK), aztreonam (AZT), rifampicin (RFP) and piperacillin (PIPC), MIC values were determined for single and double combinations. Based on the MIC values, fractional inhibitory concentration index values were calculated and the combined effects (synergy action or additive action) were evaluated. The three strongest drugs among the tested combinations were i) CL + RFP (synergy, 80.0%; additive, 17.5%), ii) RFP + ABK (synergy, 7.5%; additive, 70.0%) and iii) RFP + AZT (synergy, 5.0%; additive, 77.5%). In these cases, the arithmetic mean MIC value of each drug significantly decreased as follows: i) 1.38 microg/mL (alone) and 0.26 microg/mL (with RFP) for CL, 19.85 microg/mL (alone) and 1.85 microg/mL (with CL) for RFP; ii) 19.85 microg/mL (alone) and 7.53 microg/mL (with ABK) for RFP, 8.87 microg/mL (alone) and 2.79 microg/mL (with RFP) for ABK; iii) 19.85 microg/mL (alone) and 10.15 microg/mL (with AZT) for RFP, 28.3 microg/ mL (alone) and 6.65 microg/mL (with RFP) for AZT. Of 40 strains, metallo-beta-lactamase and aminoglycoside 6'-N-acetyltransferase were found in 20 and 37 strains, respectively; however, no significant influence of these factors was observed on the combined effects of i), ii) and iii). The results of this study provide an in vitro rationale for RFP plus CL, ABK or AZT as an effective combination therapy for MDRP infections, although the results should be verified and compared with other antibacterial drugs in further studies.

Genomic characterization of Staphylococcus aureus isolated from patients admitted to intensive care units of a tertiary care hospital: epidemiological risk of nasal carriage of virulent clone during admission.

We conducted a molecular epidemiological study of Staphylococcus aureus using whole-genome sequence data and clinical data of isolates from nasal swabs of patients admitted to the intensive care unit (ICU) of Hiroshima University hospital. The relationship between isolate genotypes and virulence factors, particularly for isolates that caused infectious diseases during ICU admission was compared with those that did not. The nasal carriage rates of methicillin-resistant S. aureus (MRSA) and methicillin-susceptible S. aureus (MSSA) in patients admitted to the ICU were 7.0% and 20.1%, respectively. The carriage rate of community-acquired (CA)-MRSA was 2.3%, accounting for 32.8% of all MRSA isolates. Whole-genome sequencing analysis of the MRSA isolates indicated that most, including CA-MRSA and healthcare-associated (HA)-MRSA, belonged to clonal complex (CC) 8 [sequence type (ST) 8] and SCCmec type IV. Furthermore, results for three disease foci (pneumonia, skin and soft tissue infection, and deep abscess) and the assessment of virulence factor genes associated with disease conditions [bacteremia, acute respiratory distress syndrome (ARDS), disseminated intravascular coagulopathy (DIC), and septic shock] suggested that nasal colonization of S. aureus clones could represent a risk for patients within the ICU. Particularly, MRSA/J and MSSA/J may be more likely to cause deep abscess infection; ST764 may cause ventilation-associated pneumonia, hospital-acquired pneumonia and subsequent bacteremia, and ARDS, and tst-1-positive isolates may cause DIC onset.IMPORTANCENasal colonization of MRSA in patients admitted to the intensive care unit (ICU) may predict the development of MRSA infections. However, no bacteriological data are available to perform risk assessments for Staphylococcus aureus infection onset. In this single-center 2-year genomic surveillance study, we analyzed all S. aureus isolates from nasal swabs of patients admitted to the ICU and those from the blood or lesions of in-patients who developed infectious diseases in the ICU. Furthermore, we identified the virulent clones responsible for causing infectious diseases in the ICU. Herein, we report several virulent clones present in the nares that are predictive of invasive infections. This information may facilitate the design of preemptive strategies to identify and eradicate virulent MRSA strains, reducing nosocomial infections within the ICU.

A case of bloodstream infection caused by Ruminococcus gnavus without gastrointestinal involvement.

We report a case of bloodstream infection due to Ruminococcus gnavus (R. gnavus) associated with pelvic abscess in a 74-year-old female patient undergoing radiotherapy for cervical cancer. Gram staining of positive anaerobic blood cultures revealed short chains of gram-positive cocci. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry was performed directly on the blood culture bottle, and 16S rRNA sequencing identified the bacterium as R. gnavus. There was no leakage from the sigmoid colon to rectum on enterography, and R. gnavus was not found in the culture of her pelvic abscess. After the administration of piperacillin/tazobactam, her condition markedly improved. This patient with R. gnavus infection demonstrated no gastrointestinal involvement, whereas past published cases reported diverticulitis or intestinal damage. It is possible that bacterial translocation of R. gnavus occurred from the gut microbiota, due to damage to the intestinal tract caused by radiation.

Case Report: Emphysematous Pyelonephritis With a Congenital Giant Ureterocele.

A 14-year-old girl noticed malodorous urine and experienced left flank pain. The patient was presented to our hospital with gradually increasing pain. She had no underlying disease but had a history of pain on micturition for several days. Hematologic examination indicated low white blood cell and platelet counts and a high serum lactate level. Computed tomography showed that a part of the parenchyma of the left kidney had poor contrast and was deteriorated, with fluid and gas retention from the perirenal region to the retroperitoneal cavity. A left hydroureter and large ureterocele were observed in the bladder. She was diagnosed with emphysematous pyelonephritis (EPN) with a giant congenital ureterocele. Vasopressors and blood transfusion failed to maintain normal circulatory dynamics, and an open left nephrectomy and transurethral ureterocele fenestration were performed. The excised outer portion of the left kidney was dissolved by the infection and replaced with blood clots and necrotic tissue. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry identified the inflammatory, gas-producing bacteria Actinotignum schaalii, Peptoniphilus asaccharolyticus, and Actinomyces odontolyticus. Meropenem was administered for 4 days postoperatively and then de-escalated to sulbactam/ampicillin for another 10 days. The patient was discharged on day 17 of hospitalization, and the postoperative course remained favorable. EPN is extremely rare in pediatric patients, and it is believed that nephrectomy is sometimes necessary if the patient does not have normal circulatory dynamics despite the use of catecholamines.