Primary Bacteremia Research Articles

Streptococcus agalactiae bacteremia in non-pregnant adult patients at two teaching hospitals

Streptococcus agalactiae or group B streptococcus (GBS) is a frequent pathogen in immunocompromised adults. The aim of this study was to determine the relative frequency, clinical presentation, antimicrobial susceptibility profile, and risk factors associated with GBS bacteremia in non-pregnant adult patients. We conducted a retrospective analysis of blood cultures performed in two hospitals between the years 2009–2013. From 1110 bacteremia episodes, 13 were caused by GBS, all of which were susceptible to ampicillin. GBS bacteremia was more frequent in females and in patients older than 60 years of age. The most frequent comorbidities were chronic kidney disease, cardiac failure and neoplasia. History of appendectomy was detected in 53.8% of the patients, being the most relevant comorbidity for GBS bacteremia in the multivariate analysis (OR 4.13, p=0.012). The main presentations were primary bacteremia and soft tissue infection. GBS bacteremia was infrequent in our institution, and a history of appendectomy might be related to bacteremia occurrence.

EFFECT of daily antiseptic body wash with octenidine on nosocomial primary bacteraemia and nosocomial multidrug-resistant organisms in intensive care units: design of a multicentre, cluster-randomised, double-blind, cross-over study

IntroductionNosocomial infections are serious complications that increase morbidity, mortality and costs and could potentially be avoidable. Antiseptic body wash is an approach to reduce dermal micro-organisms as potential pathogens on...

Retrospective Evaluation of the Use of Ceftolozane/Tazobactam at a Large Academic Medical Center

Background Ceftolozane/tazobactam is currently Food and Drug Administration–approved for the treatment of complicated intra-abdominal and urinary tract infections; however, it is often used in clinical practice for nosocomial pneumonia, particularly due to Pseudomonas aeruginosa. Previous data in this area are limited to small case studies. Methods This was a retrospective case series of all patients receiving ceftolozane/tazobactam for a variety of infectious indications at a large academic medical center. Results There were 60 cases included in this evaluation. Most patients were treated for pneumonia (34 [56.7%]), followed by intra-abdominal infection (11 [18.3%]), skin and soft tissue infection (3 [5%]), primary bacteremia (4 [6.7%]), bone and joint infection (2 [3.3%]), and pleural space infection (2 [3.3%]); 12 patient encounters (20%) had a concomitant bacteremia. Most patients had P. aeruginosa isolated (86.7%): 18 (34.6%) of these were non–multidrug resistant (MDR), 21 MDR (40.4%), and 13 extensively drug resistant (25%). The overall ceftolozane/tazobactam susceptibility rate was 83% with rates of 94.1%, 94.7%, and 45.5%, respectively, for non-MDR, MDR, and extensively drug-resistant isolates. Clinical cure was achieved in 25 (64.1%), clinical failure occurred in 10 (25.6%), and clinical status was unable to be determined in 4 cases (10.3%). Ten patients died in the hospital while on ceftolozane/tazobactam. Conclusions It seems that ceftolozane/tazobactam is a reasonable option for P. aeruginosa infections, yet prospective analyses are needed to further guide dosing recommendations and provide additional insight into patient outcomes associated with the use of this agent.

Incidence, clinical features, and implications on outcomes of neonatal late-onset sepsis with concurrent infectious focus

BackgroundNeonatal bloodstream infection (BSI) is the most important cause of morbidity and mortality in the neonatal intensive care unit (NICU). Although most neonatal BSIs are primary bacteremia, some are associated with a focus of infection. This distinction is not well characterized.MethodsAll patients with neonatal late-onset sepsis (LOS) between January 2006 and December 2013 were enrolled. LOS was categorized as a BSI with a concurrent focus of infection if LOS occurred before or within 24 h after the diagnosis of a specific infectious entity, and as “primary bacteremia” if no concurrent focus of infection was identified. Data concerning demographics, hospital course, microbiology, and outcomes were compared via univariate and multivariate analyses.ResultsOf 948 episodes of neonatal LOS, 781 (82.4%) were primary bacteremia, whereas 167 (17.6%) were associated with a known focus of infection, including meningitis (n = 51, 5.4%), ventilator-associated pneumonia (VAP) (n = 36, 3.8%), catheter-related bloodstream infections (n = 57, 6.0%), and necrotizing enterocolitis (NEC) (n = 21, 2.2%). The majority of NEC-associated BSIs were caused by gram-negative bacilli (85.7%). Group B streptococcus accounted for nearly one-third of all meningitis cases (29.4%). Although sepsis-attributable mortality was comparable between primary bacteremia and neonatal BSIs with a focus of infection, neonatal BSIs with meningitis, VAP, and NEC had significantly higher rates of infectious complications. The independent risk factors of sepsis-attributable mortality were infectious complications (Odds ratio [OR] 6.98; 95% confidence interval [CI] 3.64–13.39, P < 0.001); history of one or more than one previous episode(s) of BSI (OR 2.40 and 7.40; 95% CI 1.21–4.74 and 3.70–14.78, P = 0.012 and <0.001, respectively); and underlying secondary pulmonary hypertension in neonates (OR 4.77; 95% CI 1.91–11.96, P = 0.001).ConclusionsA considerable proportion of neonatal LOS can be associated with known infectious foci in the NICU. The microbiologic etiology of neonatal LOS with a concurrent focus of infection is significantly different from that of primary bacteremia. Neonatal BSIs with concurrent meningitis, VAP, or NEC are significantly more likely to have infectious complications. This association independently leads to sepsis-attributable mortality.

Clinical and microbiological characteristics of unusual manifestations of invasive pneumococcal disease

IntroductionInvasive pneumococcal disease (IPD) typically presents as bacterial pneumonia, meningitis or primary bacteraemia. However, Streptococcus pneumoniae can produce infection at any level of the body (endocarditis, arthritis, spontaneous bacterial peritonitis, etc.), which is also known as unusual IPD (uIPD). There are very limited data available about the clinical and microbiological profile of these uncommon manifestations of pneumococcal disease. Our aim was to analyse clinical forms, microbiological profile, epidemiology and prognosis of a cohort of patients with unusual invasive pneumococcal disease (uIPD). MethodsWe present a retrospective study of 389 patients (all adult and paediatric patients diagnosed during the period) diagnosed with IPD at our hospital (Complejo Hospitalario Universitario de Vigo) between 1992 and 2014. We performed an analysis of clinical, microbiological and demographical characteristics of patients comparing the pre-pneumococcal conjugate vaccine (PCV) period with the post-vaccination phase. IPD and uIPD were defined as follows; IPD: infection confirmed by the isolation of S. pneumoniae from a normally sterile site, which classically presented as bacterial pneumonia, meningitis or primary bacteraemia; uIPD: any case of IPD excluding pneumonia, meningitis, otitis media, rhinosinusitis or primary bacteraemia. ResultsA total of 22 patients (6%) met the criteria of uIPD. A Charlson index >2 was more prevalent in uIPD patients than IPD patients (45% vs 24%; p=0.08). The most common clinical presentation of uIPD was osteoarticular infection (8 patients, 36%), followed by gastrointestinal disease (4 patients, 18%). Infection with serotypes included in PCV-13 was significantly higher in IPD patients (65%) than in patients with uIPD, 35% (p=0.018). Conversely, infection with multidrug-resistant strains was higher among patient with uIPD (27% vs 9%; p=0.014). The all-cause mortality rate was 15%, 13% in the IPD group and 32% among patients with uIPD (p=0.07). According to the multivariate analysis, a Charlson Index >2 (OR 5.1, 95% CI, 1.8–14.0) and a Pitt Score >2 (OR 1.4, 95% CI, 1.2–1.9) were independent predictors of mortality. ConclusionuIPD is a rare entity that affects patients with more comorbidities than typical IPD and it is usually caused by non-vaccine serotypes with greater antimicrobial resistance.

Impact of appropriateness of empiric therapy on outcomes in community-onset bacteremia by extended-spectrum-β-lactamase producing Escherichia coli and Klebisella pneumoniae definitively treated with carbapenems.

Despite a significant increase of bloodstream infection caused by extended-spectrum-β-lactamase (ESBL)-producing Enterobacteriaceae in the community-setting, information regarding clinical outcomes of inappropriate empiric therapy (IAT) in patients with those infections is limited. A multicenter-retrospective cohort study was conducted in four hospitals. A total of 249 adults were identified to have community-onset bacteremia caused by ESBL-producing Escherichia coli and Klebsiella pneumoniae, and definitively treated with carbapenems. According to the appropriateness of empiric therapy, individuals were divided into an appropriate empiric therapy (AT) group (n=106) and IAT group (n=143). Patients who received AT showed more severe underlying conditions including underlying solid cancer, healthcare-association and intensive care unit (ICU) care, compared to the IAT group. Primary bacteremia was more commonly found in the AT group than in the IAT group, while urinary tract infection predominated more frequently in the IAT group than in the AT group. Multivariate analysis using propensity score analysis indicated that inappropriateness of empiric therapy was not an independent risk factor for 30-day death. ICU care, respiratory tract infection and underlying liver, renal and connective tissue diseases were significantly associated with mortality. In patients with bloodstream infections caused by ESBL-producing E. coli and K. pneumoniae in the community-setting, delay in appropriate therapy was not associated with an increased rate of death if the patients were definitively treated with carbapenems.

Lipid peroxidation in Gram-negative bacteremia modulates the risk for septic shock and infections by resistant Klebsiella pneumoniae.

Controversies in outcomes with the parenteral administration of antioxidants as adjuvant therapies led to the measurement of malondialdehyde (MDA), a product of lipid peroxidation, in serum collected from 120 patients with primary Gram-negative bacteremia during the first 24 h from sepsis onset. MDA was measured by the thiobarbiturate assay, followed by high-performance liquid chromatography (HPLC) analysis. After receiver operator characteristic (ROC) curve analysis, patients were divided into those with high levels of MDA and low levels of MDA. The primary endpoint was the association of the level of MDA with septic shock. The level of MDA as an index of neutrophil function and associations with outcome and with infections by carbapenem-resistant Klebsiella pneumoniae were the secondary endpoints. In total, 63 patients had high and 57 had low MDA levels; 27% and 49.1%, respectively, had septic shock (p = 0.015). The rate of the concentration of MDA to the total neutrophil count was used as an expression of neutrophil function; this was lower among patients with septic shock. The odds ratio (OR) for death among patients without septic shock and low level of MDA was 4.00; this was 0.48 for patients with septic shock (p = 0.020 between the two ORs). The OR for resistance to carbapenems among patients with bacteremia by K. pneumoniae and low level of MDA was 7.50 (p = 0.011 compared to patients with bacteremia by other pathogens). Low level of circulating MDA is associated with susceptibility to septic shock and infections by carbapenem-resistant K. pneumoniae.

Emergence of a Staphylococcus aureus Clone Resistant to Mupirocin and Fusidic Acid Carrying Exotoxin Genes and Causing Mainly Skin Infections.

Skin and soft tissue infections (SSTIs) caused by mupirocin-resistant Staphylococcus aureus strains have recently increased in number in our settings. We sought to evaluate the characteristics of these cases over a 43-month period. Data for all community-acquired staphylococcal infections caused by mupirocin-resistant strains were retrospectively reviewed. Genes encoding products producing high-level resistance (HLR) to mupirocin (mupA), fusidic acid resistance (fusB), resistance to macrolides and lincosamides (ermC and ermA), Panton-Valentine leukocidin (PVL) (lukS/lukF-PV), exfoliative toxins (eta and etb), and fibronectin binding protein A (fnbA) were investigated by PCRs in 102 selected preserved strains. Genotyping was performed by SCCmec and agr typing, whereas clonality was determined by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). A total of 437 cases among 2,137 staphylococcal infections were recorded in 2013 to 2016; they were all SSTIs with the exception of 1 case of primary bacteremia. Impetigo was the predominant clinical entity (371 cases [84.9%]), followed by staphylococcal scalded skin syndrome (21 cases [4.8%]), and there were no abscesses. The number of infections detected annually increased during the study years. All except 3 isolates were methicillin susceptible. The rates of HLR to mupirocin and constitutive resistance to clindamycin were 99% and 20.1%, respectively. Among the 102 tested strains, 100 (98%) were mupA positive and 97 (95%) were fusB positive, 26/27 clindamycin-resistant strains (96.3%) were ermA positive, 83 strains (81.4%) were lukS/lukF positive, 95 (93%) carried both eta and etb genes, and 99 (97%) were fnbA positive. Genotyping of methicillin-sensitive S. aureus (MSSA) strains revealed that 96/99 (96.7%) belonged to one main pulsotype, pulsotype 1, classified as sequence type 121 (ST121). The emergence of a single MSSA clone (ST121) causing impetigo was documented. Resistance to topical antimicrobials and a rich toxinogenic profile confer to this clone adaptability for spread in the community.

Prevalence of methicillin-resistant Staphylococcus aureus (MRSA) infection and the molecular characteristics of MRSA bacteraemia over a two-year period in a tertiary teaching hospital in Malaysia

BackgroundMethicillin-resistant Staphylococcus aureus (MRSA) is an established pathogen that causes hospital- and community-acquired infections worldwide. The prevalence rate of MRSA infections were reported to be the highest in Asia. As there is limited epidemiological study being done in Malaysia, this study aimed to determine the prevalence of MRSA infection and the molecular characteristics of MRSA bacteraemia.MethodsTwo hundred and nine MRSA strains from year 2011 to 2012 were collected from a tertiary teaching hospital in Malaysia. The strains were characterized by antimicrobial susceptibility testing, staphylococcal cassette chromosome mec (SCCmec) typing, detection of Panton-Valentine leukocidin (PVL) gene, multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE). Patient’s demographic and clinical data were collected and correlated with molecular data by statistical analysis.ResultsMale gender and patient >50 years of age (p < 0.0001) were significantly associated with the increased risk of MRSA acquisition. Fifty-nine percent of MRSA strains were HA-MRSA that carried SCCmec type II, III, IV and V while 31% were CA-MRSA strains with SCCmec III, IV and V. The prevalence of PVL gene among 2011 MRSA strains was 5.3% and no PVL gene was detected in 2012 MRSA strains. All of the strains were sensitive to vancomycin. However, vancomycin MIC creep phenomenon was demonstrated by the increased number of MRSA strains with MIC ≥1.5 μg/mL (p = 0.008) between 2011 and 2012. Skin disease (p = 0.034) and SCCmec type III (p = 0.0001) were found to be significantly associated with high vancomycin MIC. Forty-four percent of MRSA strains from blood, were further subtyped by MLST and PFGE. Most of the bacteraemia cases were primary bacteraemia and the common comorbidities were diabetes, hypertension and chronic kidney disease. The predominant pulsotype was pulsotype C exhibited by SCCmec III-ST239. This is a first study in Malaysia that reported the occurrence of MRSA clones such as SCCmec V-ST5, untypeable-ST508, SCCmec IV-ST1 and SCCmec IV-ST1137.ConclusionsSCCmec type III remained predominant among the MRSA strains in this hospital. The occurrence of SCCmec IV and V among hospital strains and the presence of SCCmec III in CA-MRSA strains are increasing. MRSA strains causing bacteraemia over the two-year study period were found to be genetically diverse.

Proposal for shorter antibiotic therapies

ObjectivesReducing antibiotic consumption has now become a major public health priority. Reducing treatment duration is one of the means to achieve this objective. Guidelines on the therapeutic management of the most frequent infections recommend ranges of treatment duration in the ratio of one to two. The Recommendation Group of the French Infectious Diseases Society (SPILF) was asked to collect literature data to then recommend the shortest treatment durations possible for various infections. MethodsAnalysis of the literature focused on guidelines published in French and English, supported by a systematic search on PubMed. Articles dating from one year before the guidelines publication to August 31, 2015 were searched on the website. ResultsThe shortest treatment durations based on the relevant clinical data were suggested for upper and lower respiratory tract infections, central venous catheter-related and uncomplicated primary bacteremia, infective endocarditis, bacterial meningitis, intra-abdominal, urinary tract, upper reproductive tract, bone and joint, skin and soft tissue infections, and febrile neutropenia. Details of analyzed articles were shown in tables. ConclusionThis work stresses the need for new well-conducted studies evaluating treatment durations for some common infections. Following the above-mentioned work focusing on existing literature data, the Recommendation Group of the SPILF suggests specific study proposals.

Characteristics of Staphylococcus aureus Bacteraemia and Predictors of Early and Late Mortality.

We aimed to describe the characteristics of patients with Staphylococcus aureus bacteremia and to evaluate the risk factors associated with early (7-day) and late (30-day) mortality. We performed an observational study including all consecutive episodes of Staphylococcus aureus bacteremia diagnosed at two Italian university hospitals during 2010–2014. A total of 337 patients were included. Mean age was 69 years (range, 57–78) and 65% were males. Methicillin-resistant S. aureus (MRSA) was identified in 132/337 (39%)cases. Overall 7- and 30-day mortality were 13% and 26%, respectively. Early mortality was associated with increased Charlson scores (OR 1.3, 95% CI 1.1–1.5), MRSA bacteremia (OR 3.2, 95% CI 1.4–8.1), presentation with septic shock (OR 13.5, 95% CI 5.4–36.4), and occurrence of endocarditis (OR 4.5, 95%CI 1.4–14.6). Similar risk factors were identified for late mortality, including increased Charlson scores (OR 1.2, 95% CI 1.1–1.4), MRSA bacteremia (OR 2.1, 95% CI 1.2–3.9), presentation with septic shock (OR 4, 95%CI 1.7–9.7), occurrence of endocarditis (OR 3.8, 95% CI 1.4–10.2) as well as Child C cirrhosis (OR 3.9, 95% CI 1.1–14.4) and primary bacteremia (OR 2.5, 95%CI 1.3–5). Infectious disease consultation resulted in better outcomes both at 7 (OR 0.1, 95% CI 0.05–0.4) and at 30 days (OR 0.4, 95% CI 0.2–0.7). In conclusion, our study highlighted high rates of MRSA infection in nosocomial Staphylococcus aureus bacteremia. Multiple comorbidities, disease severity and methicillin-resistance are key factors for early and late mortality in this group. In patients with Staphylococcus aureus bacteremia, infectious disease consultation remains a valuable tool to improve clinical outcome.

Blood culture-PCR to optimise typhoid fever diagnosis after controlled human infection identifies frequent asymptomatic cases and evidence of primary bacteraemia

SummaryBackgroundImproved diagnostics for typhoid are needed; a typhoid controlled human infection model may accelerate their development and translation. Here, we evaluated a blood culture-PCR assay for detecting infection after controlled human infection with S. Typhi and compared test performance with optimally performed blood cultures.Methodology/Principal findingsCulture-PCR amplification of blood samples was performed alongside daily blood culture in 41 participants undergoing typhoid challenge. Study endpoints for typhoid diagnosis (TD) were fever and/or bacteraemia. Overall, 24/41 (59%) participants reached TD, of whom 21/24 (86%) had ≥1 positive blood culture (53/674, 7.9% of all cultures) or 18/24 (75%) had ≥1 positive culture-PCR assay result (57/684, 8.3%). A further five non-bacteraemic participants produced culture-PCR amplicons indicating infection; overall sensitivity/specificity of the assay compared to the study endpoints were 70%/65%. We found no significant difference between blood culture and culture-PCR methods in ability to identify cases (12 mismatching pairs, p = 0.77, binomial test). Clinical and stool culture metadata demonstrated that additional culture-PCR amplification positive individuals likely represented true cases missed by blood culture, suggesting the overall attack rate may be 30/41 (73%) rather than 24/41 (59%). Several participants had positive culture-PCR results soon after ingesting challenge providing new evidence for occurrence of an early primary bacteraemia.Conclusions/SignificanceOverall the culture-PCR assay performed well, identifying extra typhoid cases compared with routine blood culture alone. Despite limitations to widespread field-use, the benefits of increased diagnostic yield, reduced blood volume and faster turn-around-time, suggest that this assay could enhance laboratory typhoid diagnostics in research applications and high-incidence settings.

Serial Procalcitonin as a Predictor of Bacteremia and Need for Intensive Care Unit Care in Adults With Pneumonia, Including Those With Highest Severity: A Prospective Cohort Study.

BackgroundProcalcitonin (PCT) is a prohormone that rises in bacterial pneumonia and has promise in reducing antibiotic use. Despite these attributes, there are inconclusive data on its use for clinical prognostication. We hypothesize that serial PCT measurements can predict mortality, intensive care unit (ICU) admission, and bacteremia.MethodsA prospective cohort study of inpatients diagnosed with pneumonia was performed at a large tertiary care center in Boston, Massachusetts. Procalcitonin was measured on days 1 through 4. The primary endpoint was a composite adverse outcome defined as all-cause mortality, ICU admission, and bacteremia. Regression models were calculated with area under the receiver operating characteristic curve (AUC) as a measure of discrimination.ResultsOf 505 patients, 317 patients had a final diagnosis of community-acquired pneumonia (CAP) or healthcare-associated pneumonia (HCAP). Procalcitonin was significantly higher for CAP and HCAP patients meeting the composite primary endpoint, bacteremia, and ICU admission, but not mortality. Incorporation of serial PCT levels into a statistical model including the Pneumonia Severity Index (PSI) improved the prognostic performance of the PSI with respect to the primary composite endpoint (AUC from 0.61 to 0.66), bacteremia (AUC from 0.67 to 0.85), and need for ICU-level care (AUC from 0.58 to 0.64). For patients in the highest risk class PSI >130, PCT was capable of further risk stratification for prediction of adverse outcomes.ConclusionSerial PCT measurement in patients with pneumonia shows promise for predicting adverse clinical outcomes, including in those at highest mortality risk.

Treatment of Carbapenem-Resistant Enterobacteriaceae Infections with Ceftazidime-Avibactam

BackgroundCRE is an urgent threats to public health with a high mortality estimated at >30–50%. Until recently, polymyxin-based antibiotics were the only available options. However, a new therapeutic option has become available: ceftazidime-avibactam. We sought to describe outcomes from these infections treated with ceftazidime-avibactam.MethodsFrom 9/2015 to 12/ 2016, we reviewed charts of 11 patients infected with CRE who received ceftazidime-avibactam at USC (Los Angeles, CA). Sixteen isolates analyzed. All isolates were resistant to meropenem (MIC ≥ 16). Carbapenemase production confirmed by detection of blaKPC. Clinical success defined as clinical improvement, lack of recurrence, and survival in 90 days. Recurrence defined as clinical signs of infection and recovery of CRE after ≥ 7 days of treatment.ResultsThe median age was 49 (35-89); 73% (7/11) female; and 27% (3/11) solid organ transplants. All CRE infections caused by Klebsiella pneumoniae. All sequence type 258, 7/11 harboring blaKPC-2 and 4/11 blaKPC-3. Nine capsular type wzi-154 and 2 wzi-29. qSOFA score was 0 (0–2) predicting mortality of 3%. Seven had intraabdominal infections; 2 pyelonephritis, 1 skin and soft-tissue infection, and 1 primary bacteremia. There were five episodes of secondary bacteremia. The patients were treated for a median duration of 15 (3-43) days. All received other antibiotics prior to ceftazidime-avibactam. Eighty-seven percent (9/11) treated with monotherapy and 13% (2/11) in conjunction with colistemethate sodium. 27% (3/11) were receiving CRRT or hemodialysis during treatment. No incidents of renal toxicity observed using RIFLE criteria. Clinical success was 73% (8/11); 30 day survival rate 82% (9/11); 90 day survival rate 73% (8/11); and in hospital mortality 27% (3/11). Patients receiving CRRT or hemodialysis had 75% (3/4) mortality (P = 0.02). Recurrence occurred in 18% (2/11). Decreased sensitivity to ceftazidime-avibactam noted in one patient. 27% (3/11) had CRE isolated after ≥ 7 days treatment.ConclusionIn CRE-infected patient treated with ceftazidime-avibactam, the overall mortality rate was 27% with the highest mortality among those receiving renal replacement therapy which was comparable to a prior studies. Additional research is needed to optimize the use of ceftazidime-avibactam to treat CRE infections.Disclosures All authors: No reported disclosures.

Streptococcus pneumoniae – Aspects of the implication in human pathology, epidemiology, diagnosis, treatment and prevention of pneumococcal infections

Streptococcus pneumoniae, part of the commensal flora of the nasopharynx, a bacterial conditioned pathogen, is the most common cause of respiratory tract infections. It is a fastidious bacterium that belongs to the family Streptococcaceae, genus Streptococcus. Pneumococcus has a number of virulence factors: endogenous (cellular components) and exogenous (enzymes, toxins), which play an important role in the pathogenesis of pneumococcal disease. Pneumococcal infections have different degrees of severity, from mild/moderate respiratory infections = non-invasive infections, which are the most common ones (otitis media, sinusitis, conjunctivitis), to very severe invasive infections (primary bacteremia, pneumonia with bacteremia, meningitis) – defined by the isolation of S. pneumoniae from a normally sterile place (blood, cerebrospinal fluid, pleural fluid etc.). Out of more than 90 pneumococcal serotypes, only 20 to 30 are responsible for the majority of invasive pneumococcal disease (IPD). These infections and their risk factors are summarized in the article. The diagnosis of pneumococcal disease is achieved through the isolation and identification of the pathogen, both by phenotypic and molecular methods. The treatment of the pneumococcal infections, mainly by antibiotherapy, is recommended depending on the location and severity of the infection, the results of antibiotic susceptibility testing and factors related to the human host. Regarding the emergence of antibiotic resistance in S. pneumoniae, it is very important to sustain the surveillance of pneumococcal disease and the prevention through vaccination, which determined a reduction in the incidence of IPD and antibiotic resistance. However, due to the limited use of pneumococcal vaccine, S. pneumoniae still remains the most common etiologic agent of severe infections. It is therefore necessary to implement a surveillance program to assess the burden of pneumococcal disease, in order to establish effective interventions, such as conjugate vaccines and antibiotic stewardship programs.

Detection and Clinical Implications of Biofilm Formation Among Clinical Isolates of Sphingomonas paucimobilis in Turkey

Background: Sphingomonas paucimobilis is a non-fermentative bacillus and found widely in nature. It acquires great interest in biofouling by production of biofilm. However, S. paucimobilis as a biofilm producer, is not studied in medical aspect. In this study we aimed to assess the biofilm production as a virulence factor in clinical isolates of S. paucimobilis together with patient demographics, clinical aspects, risk factors, and outcomes. Methods: During 5 year-period, total numbers of 43 S. paucimobilis isolates identified in a clinical microbiology laboratory of an university hospital in Turkey. Thirty-three of the isolates, which were isolated from patients with clinically determined infection, were enrolled in this study. Patients’ data were collected retrospectively. VITEK II automated system (bioMerieux, Marcy L’Eoile, France) was used for identification and antimicrobial susceptibility testing. Christiansen tube method was used to determine biofilm formation. Results: All the clinical isolates of S. paucimobilis produced biofilms. Primary bacteraemia (n = 16) was the most common clinical manifestation. Twenty-four of the patients were followed in the intensive care unit. Twenty-two patients had indwelling catheters. Malignancy (n = 11) and diabetes mellitus (n = 10) were the most common concomitant diseases. Tigecycline, carbapenems and aminoglycosides were the most susceptible antimicrobial agents. Degree of biofilm formation was correlated only with blood samples (P = 0.003) in the sample types group and a stay in the intensive care unit (P = 0.002) in the risk factors group. Conclusions: Sphingomonas paucimobilis can cause serious infections, especially in immunocompromised patients with determined risk factors such as indwelling catheters and diabetes mellitus, due to the effects of multiple virulence factors, together with biofilm formation.

High Incidence of Invasive Group A Streptococcal Infections in Remote Indigenous Communities in Northwestern Ontario, Canada.

BackgroundWorldwide, indigenous populations appear to be at increased risk for invasive group A streptococcal (iGAS) infections. Although there is empirical evidence that the burden of iGAS disease is significant among remote First Nations communities in Northwestern Ontario, Canada, the epidemiology of iGAS infections in the area remains poorly characterized.MethodsIndividuals that met case definition for iGAS disease and whose laboratory specimens were processed by Meno Ya Win Health Centre in Sioux Lookout, Canada or who were reported to Thunder Bay District Health Unit, Canada were identified for the period 2009 to 2014. Case demographics, clinical severity, comorbidities, and risk factors were collected through chart review. Strain typing and antibiotic susceptibility were determined when possible. Basic descriptive statistics were calculated.ResultsSixty-five cases of iGAS disease were identified, for an annualized incidence of 56.2 per 100 000. Primary bacteremia was present in 26.2% of cases, and cellulitis was identified in 55.4% of cases. The most common comorbidities identified were diabetes (38.5%) and skin conditions (38.5%). Prevalent risk factors included alcohol dependence (25%). Fourteen different emm types were identified among 42 isolates, with the most common being emm114 (17.4%), emm11 (15.2%), and emm118 (13.0%). Resistance to erythromycin and clindamycin was found in 24.6% of isolates.ConclusionsRural and remote First Nations communities in Northwestern Ontario experience iGAS infections at a rate 10 times the provincial and national average. Compared with other North American series, a lower proportion of isolates causing infection were of emm types included in candidate GAS vaccines.

Carbapenem-resistant Pseudomonas aeruginosa : association with virulence genes and biofilm formation

Pseudomonas aeruginosa is an opportunistic pathogen that causes frequently nosocomial infections, currently becoming more difficult to treat due to the various resistance mechanisms and different virulence factors. The purpose of this study was to determine the risk factors independently associated with the development of bacteremia by carbapenem-resistant P. aeruginosa, the frequency of virulence genes in metallo-β-lactamases producers and to evaluate their ability to produce biofilm. We conducted a case–control study in the Uberlândia Federal University – Hospital Clinic, Brazil. Polymerase Chain Reaction was performed for metallo-β-lactamases and virulence genes. Adhesion and biofilm assays were done by quantitative tests. Among the 157 strains analyzed, 73.9% were multidrug-resistant, 43.9% were resistant to carbapenems, 16.1% were phenotypically positive for metallo-β-lactamases, and of these, 10.7% were positive for blaSPM gene and 5.3% positive for blaVIM. The multivariable analysis showed that mechanical ventilation, enteral/nasogastric tubes, primary bacteremia with unknown focus, and inappropriate therapy were independent risk factors associated with bacteremia. All tested strains were characterized as strongly biofilm producers. A higher mortality was found among patients with bacteremia by carbapenem-resistant P. aeruginosa strains, associated independently with extrinsic risk factors, however it was not evident the association with the presence of virulence and metallo-β-lactamases genes.

The development of current strategies for the nursing and management of bloodstream infections from short-term placed central venous catheters

Center vein puncture is important to the clinical infusion technology, however, its correlation infection rates rising trend year by year, especially catheter-related bloodstream infections have become one of the main reasons for primary bacteremia, seriously affected the patients survival rate, and the processing method of catheter-related bloodstream infections are intricate. The treatment and nursing of adult bloodstream infections caused by short-term central venous catheter (including peripheral central venous catheter placement) according to the provisions of the Infectious Diseases Society of America to update the catheter related infections of diagnosis and treatment guidelines are reviewed in this paper, to provide reference for management of adult short-term central venous catheter. Key words: Catheterization, central venous; Nursing care; Catheter related bloodstream infections

Clinical Characteristics of Primary Pneumococcal Bacteremia in Adult Patients in the Republic of Korea

Clinical Characteristics of Primary Pneumococcal Bacteremia in Adult Patients in the Republic of Korea