Coagulase-negative Staphylococcus Spp. Research Articles

Prevalence of Staphylococcus spp. from human specimens submitted to diagnostic laboratories in South Africa, 2012-2017.

Although staphylococci are commensals of the skin and mucosa of humans and animals, they are also opportunistic pathogens. Some coagulase-negative Staphylococcus spp. (CoNS), such as S. haemolyticus and S. epidermidis, are reported to be zoonotic. The prevalence of coagulase positive (CoPS), CoNS and coagulase-variable Staphylococcus spp. isolated from human clinical cases in South Africa was investigated. Retrospective records of 404 217 diagnostic laboratory submissions from 2012 to 2017 were examined and analysed in terms of time, place and person. Of the 32 different species identified, CoPS were the most frequently isolated (74.7%), followed by CoNS (18.9%). Just over half (51.2%) of the Staphylococcus isolates were from males, while females contributed 44.8%. Patients aged 0-4 years contributed the most (21.5%) isolates, with the highest number coming from KwaZulu-Natal (32.8%). Urinary specimens accounted for 29.8% of the isolates reported. There was no variation in the number of Staphylococcus isolates reported in the autumn (25.2%), winter (25.2%), spring (25.1%) and summer (24.5%) seasons. This study demonstrated the diversity of Staphylococcus spp. isolated from humans and the magnitude of infection, with the most predominant species being S. aureus and S. epidermidis. Although most isolates were CoPS, the isolation of CoNS seen in this study suggests a need to improve infection control measures in a South African context. More research is needed to investigate the determinants of the observed variations in the study.

Rates and causative pathogens of surgical site infections attributed to liver transplant procedures and other hepatic, biliary, or pancreatic procedures, 2015‐2018

Liver transplant recipients are at high risk for surgical site infections (SSIs). Limited data are available on SSI epidemiology following liver transplant procedures (LTPs). We analyzed data on SSIs from 2015 to 2018 reported to CDC's National Healthcare Safety Network to determine rates, pathogen distribution, and antimicrobial resistance after LTPs and other hepatic, biliary, or pancreatic procedures (BILIs). LTP and BILI SSI rates were 5.7% and 5.9%, respectively. The odds of SSI after LTP were lower than after BILI (adjusted odds ratio = 0.70, 95% confidence interval 0.57‐0.85). Among LTP SSIs, 43.1% were caused by Enterococcus spp., 17.2% by Candida spp., and 15.0% by coagulase‐negative Staphylococcus spp. (CNS). Percentages of SSIs caused by Enterococcus faecium or CNS were higher after LTPs than BILIs, whereas percentages of SSIs caused by Enterobacteriaceae, Enterococcus faecalis, or viridans streptococci were higher after BILIs. Antimicrobial resistance was common in LTP SSI pathogens, including E. faecium (69.4% vancomycin resistant); Escherichia coli (68.8% fluoroquinolone non‐susceptible and 44.7% extended spectrum cephalosporin [ESC] non‐susceptible); and Klebsiella pneumoniae and K. oxytoca (39.4% fluoroquinolone non‐susceptible and 54.5% ESC non‐susceptible). National LTP SSI pathogen and resistance data can help prioritize studies to determine effective interventions to prevent SSIs and reduce antimicrobial resistance in liver transplant recipients.

Efficacy of three methods used to control staphylococcal mastitis in dairy goats

Goat and sheep farming in Brazil relies on an expressive herd, especially in the Northeast region of the country, where small ruminants constitute a relevant economic activity, with milk production being an important source of income in some dry areas of the Northeastern states. However, there are still some sanitary problems in the management of dairy goats, among which mastitis is highlighted, especially that of the subclinical type. Therefore, the aim of this study was to evaluate the use of antibiotics, exclusively or in combination with vaccines, in the control of sub-clinical mastitis in small ruminants. The study was conducted on a rural property located in Santa Maria da Boa Vista-PE. Fifty-three female Saanen dairy goats were allocated into four experimental groups. An antibiotic therapy with a commercial antimicrobial based on cloxacillin was used in group 1. Group 2 received the commercial vaccine indicated for herds with an incidence of Staphylococcus strains and the same antibiotic described for Group 1. Group 3 was evaluated for the exclusive use of vaccination, and Group 4 was the control group. A microbiological examination of the milk was carried out to confirm cases of mastitis. The percentage of udders, infected by coagulase-negative Staphylococcus spp. (CNS) before and after the antibiotic + vaccine treatment was 42.8 and 7.1%, respectively. It was observed that the cloxacillin-based antibiotic could be used alone or in combination with mastitis vaccines to control staphylococcal mastitis in small ruminants. Vaccination alone was not effective in reducing the number of mastitis cases; therefore, a cross reaction against CNS was not observed. Thus, further studies to determine the potential of vaccines to control sub-clinical mastitis in small ruminants are necessary.

Asymptomatic central line-associated bloodstream infections in children implanted with long term indwelling central venous catheters in a teaching hospital, Sri Lanka

BackgroundIndwelling central venous catheters (CVC) are used to provide long term hemodialysis. The commonest and the severe complication of CVC is the central line-associated bloodstream infection (CLABSI). This study was done to assess the etiology and infectious complications of CVC in children on long term hemodialysis.MethodsChildren newly undergoing hemodialysis and having indwelling CVC were included. They were followed up to a period of 2-years to assess infectious complications. Catheter bundle care approach was employed to prevent infections and other complications. Automated culture from the central catheter and peripheral vein and 2D echocardiography were done in each hemodialysis. Serial procalcitonin (PCT) was measured. Differential time of positivity (DTP) was used to detect CLABSI. During homestay in weekly telephone conversations were done to assess features of infection, and whenever having, we have asked to admit to the tertiary care unit. Logistic regression was performed, and the significant outcome variable was considered following multivariable analysis as a risk factor.ResultsBlood cultures were positive in 1090 (74.5%) out of 1462 children. According to DTP, 410 (28%) were having CLABSI, while 520 (35.6%) were having bacteremia without CLABSI. Out of 410 CLABSI patients, 79 (19.2%) were asymptomatic. Coagulase-negative Staphylococcus spp. (CoNS) bacteremia was significantly associated with asymptomatic CLABSI. Right-sided infective endocarditis (RS-IE) was significantly associated with asymptomatic CLABSI and asymptomatic bacteremia without CLABSI. CoNS was associated significantly in RS-IE following asymptomatic CLABSI and asymptomatic bacteremia. PCT was in asymptomatic CLABSI was 1.8 ± 0.9 ng/mL while in symptomatic CLABSI was 11.3 ± 2.5 ng/ml (P = 0.02). CoNS bloodstream infection, tunneled CVC, peripherally inserted central catheter, femoral site, the number of line days > 90, receipt of vancomycin, meropenem, or linezolid in the 5 days before CLABSI diagnosis and recurrent bacteremia were risk factors for asymptomatic CLABSI.ConclusionsAsymptomatic CLABSI could be a rare occurrence. CoNS was predominantly isolated in patients with asymptomatic CLABSI. RS- IE is a well-known complication in long term indwelling CVC. CoNS was significantly associated with RS-IE following asymptomatic CLABSI. Regular procalcitonin, microbiological, and imaging studies would be essential to detect infectious complications in both symptomatic and asymptomatic patients implanted with long term indwelling CVCs.

Bacteriological Profile and Antimicrobial Susceptibility Patterns of Urine Culture Isolates from Patients in a Tertiary Care Centre in Lalitpur

Introduction: Urinary tract infection (UTI) is a microbial infection of the urinary system involving the urinary tract anywhere from kidney to urethra. It is one of the most common bacterial infections affecting men and women in developing countries with a high rate of morbidity and financial cost.
 Objectives: The objective of our study is to study the prevalence of UTI in patients attending KIST Medical College & Teaching Hospital (KISTMCTH), and determine the antimicrobial susceptibility pattern of bacteria thus isolated.
 Methodology: A total of 3742 urine samples from patients suspected of urinary tract infections presenting with the history and symptoms suggestive of urinary tract infection, attending various departments of KISTMCTH from April 2017 to April 2018 were studied. Isolates were identified by standard microbiological methods and tested for in vitro antibiotic susceptibility by modified Kirby-Bauer disc diffusion method.
 Results: Pathogenic bacteria were isolated from 646 out of 3742 urine samples (17.26%). Escherichia coli was the most common bacteria isolated (67.02%) followed by Klebsiella pneumoniae (14.5%). Other bacteria isolated were Enterococcus spp, Pseudomonas aeurigenosa, Klebsiella oxytoca, Proteus mirabilis, Satphylococcus aureus, Coagulase negative staphylococcus spp, Proteus vulgaris, Acinetobacter spp, Citrobacter freundii, Citrobacter diversus and Enterobacter spp. The isolated pathogenic bacterias were most resistant to Ampicillin (46.43%) and least resistant to Imipenem (6.03%). However, the first line antibiotic the bacterias were least resistant to was cefotaxime (7.12%).
 Conclusions: Marked resistance has been observed with commonly prescribed antibiotics like Ciprofloxacin and Norfloxacin. Therefore, studies should be conducted routinely to identify the common bacteria causing UTI and formulate appropriate antibiotic policy.

Sepsis in cancer patients residing in Zimbabwe: spectrum of bacterial and fungal aetiologies and their antimicrobial susceptibility patterns

BackgroundCancer and sepsis comorbidity is a major public health problem in most parts of the world including Zimbabwe. The microbial aetiologies of sepsis and their antibiograms vary with time and locations. Knowledge on local microbial aetiologies of sepsis and their susceptibility patterns is critical in guiding empirical antimicrobial treatment choices.MethodsThis was a descriptive cross-sectional study which determined the microbial aetiologies of sepsis from blood cultures of paediatric and adult cancer patients obtained between July 2016 and June 2017. The TDR-X120 blood culture system and TDR 300B auto identification machine were used for incubation of blood culture bottles and identification plus antimicrobial susceptibility testing, respectively.ResultsA total of 142 participants were enrolled; 50 (35.2%) had positive blood cultures, with 56.0% Gram positive, 42.0% Gram-negative bacteria and 2.0% yeast isolated. Common species isolated included coagulase negative Staphylococcus spp. (CoNS) (22.0%), E. coli (16.0%), K. pneumoniae (14.0%), E. faecalis (14.0%) and S. aureus (8.0%). Gram-negative isolates exhibited high resistance to gentamicin (61.9%) and ceftriaxone (71.4%) which are the empiric antimicrobial agents used in our setting. Amikacin and meropenem showed 85.7 and 95.2% activity respectively against all Gram-negative isolates, whilst vancomycin and linezolid were effective against 96.2 and 100.0% of all Gram-positive isolates respectively. We isolated 10 (66.7%) extended spectrum β-lactamase (ESBL) amongst the E. coli and K. pneumoniae isolates. Ten (66.7%) of the Staphylococcus spp. were methicillin resistant.ConclusionsCoNS, E. coli, K. pneumoniae, E. faecalis and S. aureus were the major microbial drivers of sepsis amongst cancer patients in Zimbabwe. Most isolates were found to be resistant to commonly used empirical antibiotics, with isolates exhibiting high levels of ESBL and methicillin resistance carriage. A nationwide survey on microbial aetiologies of sepsis and their susceptibility patterns would assist in the guidance of effective sepsis empiric antimicrobial treatment among patients with cancer.

Detection of virulence factors in coagulase-negative Staphylococcus spp. strains isolated from Emmental cheese

ABSTRACT Food prepared with products derived from animals are involved in most cases of staphylococcal poisoning; therefore, the research of Staphylococcus spp. in Emmental cheese is more applicable. The objective of this study was to identify coagulase-negative Staphylococcus spp. (CNS) in cheese using biochemical and molecular techniques to detect the presence of nine genes responsible for the production of enterotoxins. From 180 samples analyzed, 204 CNS strains were obtained and identified as being 46 (22.6%) S. saprophyticus strains, 27 (13.2%) S. hominis spp. hominis strains, 22 (10.8%) S. sciuri strains, 21 (10.3%) S. xylosus strains, 19 (9.3%) S. epidermidis strains, 19 (9.3%) S. haemolyticus strains, 17 (8.3%) S. lentus strains, 17 (8.3%) S. warneri strains, 11 (5.4%) S. equorum strains and 5 (2.5%) S. cohnni . Using the PCRm protocol, 14 (6.9%) strains with the presence of the genes on the enterotoxin E (SEE)11 (78.6%), J (SEJ) 1 (7%), C (SEC) 1 (7%) and I (SEI) 1 (7%) were detected. Based on the results, the type of package is not interfered of growth and isolated that Staphylococcus spp. in cheese. It was observed that bacteria capacity to produce coagulase cannot be understood as an indicative of enterotoxigenicity; therefore, the CNS should be considered as a target of importance in the epidemiology of staphylococcal intoxications. It can be concluded that CNS need to be included in bacterial foodborne disease research, since the genes responsible for the production of toxins were detected and none of the studied samples presented Staphylococcus spp. counting above the limits allowed by legislation.

Contribution of specific pathogens to bloodstream infection mortality in neutropenic patients with hematologic malignancies: Results from a multicentric surveillance cohort study.

Bloodstream infection (BSI) remains a serious complication in patients with hematologic malignancies and neutropenia. The risk factors for mortality after BSI and the contributions of BSI pathogens to mortality remain incompletely understood. We evaluated first BSI among adult neutropenic patients undergoing high-dose chemotherapy for hematologic malignancies in the setting of (a) an early disease stage of autologous (auto-HSCT) or allogeneic (allo-HSCT) hematopoietic stem cell transplantation or (b) for acute leukemia. Risk factors for intensive care admission and all-cause mortality were analyzed by multivariable logistic regression 7 and 30days after onset of the first BSI in the first neutropenic episode. Between 2002 and 2015, 9080 patients met the study inclusion criteria, and 1424 (16%) developed BSIs, most of them during the first week of neutropenia. Mortality during neutropenia within 7days and 30days after BSI onset was 2.5% and 5.1%, respectively, and differed considerably between BSI pathogens. Both 7-day and 30-day mortalities were highest for Pseudomonas aeruginosa BSI (16.7% and 26.7%, respectively) and lowest for BSI due to coagulase-negative Staphylococcus spp. (CoNS) and Streptococcus spp. BSI pathogens were independently associated with 7-day mortality included Paeruginosa, Klebsiella spp., Enterobacter spp., Serratia spp., and enterococci. Only gram-negative BSI and candidemia were associated with admission to intensive care within 7days after BSI onset. BSI caused by Paeruginosa continues to carry a particularly poor prognosis in neutropenic patients. The unexpected association between enterococcal BSI and increased mortality needs further study.

Pandemonium of oral flora in tobacco chewers and patients with associated oral cancer in a tertiary care hospital, Valsad, South Gujarat

Introduction: Tobacco chewing is a serious oral health problem in India responsible for halitosis, periodontitis, sub mucus fibrosis, leukoplakia and oral cancer. There is a need to understand the oral microbiological changes in tobacco chewers. Aim and Objective: To find out the changes in oral microbiota in tobacco chewing patients and patients with associated oral cancer. Materials and Methods: A case control study on 102 patients was conducted over a period of 2 months. Case group included subjects with tobacco chewing habits and presence of leukoplakia and oral cancer while control group included subjects with no tobacco chewing habits. Oral swabs collected were microscopically examined and grown on routine culture media- Blood Agar, Nutrient Agar and McConkey’s Agar. After obtaining the complete data of different bacteria isolated, a statistical analysis was made comparing the isolates from case and control group. Results: Streptococci spp. and Coagulase Negative Staphylococcispp (CONS) forms a part of normal oral flora, which was found in 79% of the control isolates but only in 49% of the case isolates. This result of normal flora being reduced in case group was statistically significant (p group, other species- Enterococci, Pseudomonas and Klebsiella were found in only 21% of control isolates while 51% of cases showed such result but Acinetobacter spp, Proteus spp and Citrobacter freundii were also isolated. Conclusion: Tobacco chewing is associated with a disruption of normal oral flora and a consequent increase in other organisms making the oral cavity more prone to ailments. Keywords: Oral flora, Tobacco chewers.

High-Level Mupirocin Resistance in Staphylococcus spp. among Health Care Workers in a Tertiary Care Hospital

Background: Nasal carriage of Staphylococcus aureus is very common among health care workers, and treatment with mupirocin is one of the choicest antibiotics available. But with the rampant usage of mupirocin like other antibiotics, the emergence of mupirocin resistance is also on rise. This resistance is both low level as well as high level among the isolated strains. Aim: To screen for the high-level mupirocin resistance among the isolated Staphylococcus strains by Kirby Bauer disk diffusion method. Materials and Methods: A total of 200 clinical isolates were tested for high level mupirocin resistance by disk diffusion method using Himedia disks. Results: Among the 200 nasal swabs, 26 (13%) showed growth of S. aureus, whereas 174 (87%) showed the growth of coagulase negative staphylococcus (CONS) spp. Mupirocin resistance was observed only among CONS spp, which was 15% for low-level mupirocin and 8% for high-level mupirocin resistance. No mupirocin resistance was observed among the Staphylococcus spp. Conclusion: The identification of Mupirocin resistance will guide us to utilize the antibiotic in a judicious way to treat the nasal carriage effectively.

Characterization of mecC gene-carrying coagulase-negative Staphylococcus spp. isolated from various animals

The presence of the methicillin resistance gene mecC in coagulase-negative Staphylococcus spp. (CoNS) is scarce. The aim of this study was to characterize mecC-positive CoNS isolated from various wild and domestic animals. The presence of the mecC gene was screened in 4299 samples from wild animals and domestic animals. Fifteen coagulase-negative staphylococci, that displayed a cefoxitin-resistant phenotype, were tested mecC-positive by PCR. Antimicrobial susceptibility testing was performed for all isolates. The 15 isolates were genotyped by sequencing of the entire class E mec gene complex (blaZ-mecC-mecR1-mecI), the ccrA and ccrB recombinase genes and other determinants within the type XI SCCmec element. DNA microarray analysis was performed and five selected isolates were additionally whole genome sequenced and analyzed. S. stepanovicii (n = 3), S. caprae (n = 1), S. warneri (n = 1), S. xylosus (n = 1) and S. sciuri (n = 9) were detected. All but the S. sciuri isolates were found to be susceptible to all non-beta lactams. The entire class E mec gene complex was detected in all isolates but ccrA and ccrB genes were not identified in S. stepanovicii and S. xylosus. The genes erm(B) and fexA (n = 4, each) were the most predominant non-beta lactam resistance genes detected in the S. sciuri isolates. Even though the presence of the mecC gene among CoNS is a rare observation, this study further expands our knowledge by showing that the mecC gene, including its allotypes, are present in more staphylococcal species from different animal species than has been previously described.

Identification of Microbes in Patients with Lumbar Disc Herniation

Apart from the conventional factors, recent evidences have suggested that lumbar disc herniation (LDH) is also associated with microbes, which is completely ignored in the management of patients with disc prolapse and disc degeneration. Therefore, the present study was carried out to identify the different microorganisms in subjects with LDH. Subjects (n = 101) who were confirmed for LDH with Magnetic Resonance Imaging and undergoing lumbar discectomy, were recruited in this study. Standard protocols for disinfection of the skin and surgical instruments were adhered. Skin scrapings, muscle biopsies and portion of the inter-vertebral disc were transferred into individually labeled Robertson’s cooked meat enrichment broth for anaerobic identification. Remaining portions of the excised disc material and muscle biopsy were taken for aerobic identification. Anaerobic isolates were identified using Gram stain and catalase test while the species identification was done by RapID ANA II ID kit. Gram stain, catalase test, DNase test and coagulase tests were used for identification of aerobic bacteria. Study confirmed 6/101 disc cultures (6%) with positive anaerobes and 12 disc cultures with coagulase negative Staphylococci spp. Among the anaerobes, two disc cultures were identified as Propionibacterium acnes and one as Gemella morbillorum. Due to slow growth, other three anaerobic cultures were not confirmed. However, they resembled the colony morphology of Gram positive bacilli. None of the control samples (skin and muscles) had any positive growth. The present study adds to the literature confirming the role of microorganisms in LDH. Present study newly identified Gemella morbillorum in the intervertebral tissue in addition to the previously reported microorganisms associated with LDH.

Acute-phase inter-alpha-trypsin inhibitor heavy chain 4 (ITIH4) levels in serum and milk of cows with subclinical mastitis caused by Streptococcus species and coagulase-negative Staphylococcus species

The aim of the study was to investigate the concentrations of acute-phase inter-α-trypsin inhibitor heavy chain 4 (ITIH4) in serum and milk of cows with subclinical mastitis caused by Streptococcus spp. (STR) and coagulase-negative Staphylococcus spp. (CNS) and healthy cows. The blood and milk samples were obtained from 60 mid-lactation, multiparous Holstein-Friesian cows from 7 herds in the Lublin region of Poland. In the milk samples from 40 cows with subclinical mastitis, Streptococcus spp. and CNS were isolated. The ITIH4 was significantly higher in serum of cows with subclinical mastitis caused both by STR and CNS compared with healthy cows. One hundred percent of animals infected with Streptococcus spp. and 89% of animals infected with Staphylococcus spp. showed ITIH4 concentration in sera higher than 0.5 mg/mL. The concentration of ITIH4 in milk also was significantly higher in cows with subclinical mastitis caused by Streptococcus spp. and Staphylococcus spp. compared with the control group. Seventy percent of cows infected by STR and CNS showed ITIH4 concentration in milk higher than 2.5 μg/mL. Milk ITIH4 concentration higher than 5 µg/mL was found in 55% of animals infected with Streptococcus spp. and in 40% of animals infected with Staphylococcus spp. No statistically significant differences were observed in ITIH4 concentrations both in serum and in milk between the studied unhealthy animal groups. These results suggest that ITIH4 may be used in the future as a novel diagnostic marker in serum and in milk of subclinical mastitis in cows.

Relationship between virulence factor genes in coagulase-negative Staphylococcus spp. and failure of antimicrobial treatment of subclinical mastitis in sheep

ABSTRACT: Coagulase-negative Staphylococcus spp. (CNS) are the main microorganisms involved in ovine mastitis. Treatment at the end of lactation can contribute towards cure and prevention of subclinical cases during the subsequent lactation. However, virulence factors and resistance mechanisms presented by CNS can decrease cure rates. The aims of the study were to identify the species of CNS in milk of mastitic ewes with and without antimicrobial treatment, and to investigate the presence of genes relating to resistance of β-lactam antimicrobials, formation of biofilms, production of enterotoxins and production of the toxic shock syndrome toxin. Cases of failure in the treatment were related with the presence/absence of the respective genes. Sixty sheep were divided into three groups: G1, without treatment; G2, animals treated via the intramammary route with 100mg of cloxacillin during drying off; and G3, sheep treated via the intramammary route with 50 mg of nanoparticulate cloxacillin. Milk samples were gathered during drying off and 15 and 30 days after the parturition of the subsequent lactation. The analyses to identify the species of CNS were carried out by means of the internal transcribe spacer technique and the investigation of the genes responsible for the virulence factors and resistance to oxacillin was performed using the polymerase chain reaction (PCR) technique. No sample was positive for the mecA gene. The only gene relating to production of enterotoxins was sec. Among the genes relating to production of biofilm, icaD was the only one identified in the three experimental groups. Staphylococcus warneri was the main species of CNS isolated during the pre and post-partum periods of the sheep. The species carrying genes relating to production of enterotoxins and biofilms were present in uncured sheep.

Isolation of Multidrug Resistant Bacteria from Patients Medical Charts.

Patient's medical charts in hospitals are potentially contaminated by pathogenic bacteria and might act as vehicles for transmission of bacterial infections.This study was aimed to determine the rate of contamination of medical charts by multidrug resistant bacteria. Sampling of total 250 patient's medical charts from different wards was done with the help of cotton swabs soaked in sterile normal saline. The swabs thus collected were cultured using standard microbiological procedures.The colonies grown were then identified with the help of colony morphology, Gram's stain and biochemical tests. Antimicrobial susceptibility testing was performed by using Kirby-Bauer disc diffusion technique. Of the total 250 charts sampled, 98.8% grew bacteria; Bacillus spp. in 40.7%, followed by Staphylococcus aureus (17%), coagulase-negative Staphylococcus spp.(CoNS) (17%), Citrobacter freundii (9.6%) and Acinetobacter spp. (4.5%). Rate of multidrug resistance was highest in Acinetobacter spp. (50%). Among 83 isolates of S. aureus, methicillin resistance was found in 29 isolates. Similarly, two out of total 9 isolates of Enterococcus spp. were vancomycin resistant. This study showed that patient's medical charts were contaminated with multidrug resistant bacteria including methicillin resistant S. aureus and vancomycin resistant Enterococcus spp. Strict hand washing before and after handling medical charts is recommended.

Blood Culture Contaminants in a Paediatric Population Retrospective study from a tertiary hospital in Oman.

Most children presenting with febrile illness require a blood culture to determine the causative organism as well as its sensitivity to antibiotics. However, false-positive results lead to unnecessary hospitalisations, prescriptions and tests. This study aimed to evaluate the impact of false-positive blood cultures among a paediatric population at a tertiary hospital in Oman. This retrospective study included all 225 children <13 years old with positive blood cultures who presented to the Sultan Qaboos University Hospital, Muscat, Oman, between July 2011 and December 2013. Blood cultures were reviewed to determine whether they were true-positive or contaminated. A total of 344 positive blood cultures were recorded during the study period, of which 185 (53.8%) were true-positive and 159 (46.2%) were contaminated. Most true-positive isolates (26.5%) were coagulase-negative Staphylococcus spp. (CONS) followed by Escherichia coli (9.7%), while the majority of contaminated isolates were CONS (67.9%) followed by Streptococcus spp. (6.9%). Children with contaminated cultures were significantly younger (P <0.001) while those with true-positive cultures required significantly more frequent hospital admissions, longer hospital stays and more frequent antibiotic prescriptions (P <0.001 each). Chronic illness and mortality was significantly more frequent among those with true-positive cultures (P <0.001 and 0.04, respectively). While white blood cell and absolute neutrophil counts were significantly higher in true-positive cultures (P <0.001 each), there was no significant difference in C-reactive protein (CRP) level (P = 0.791). In this population, CRP level was not an adequate marker to differentiate between true- and false-positive cultures. A dedicated well-trained phlebotomy team for paediatric patients is essential.

Species level identification of coagulase negative Staphylococcus spp. from buffalo using matrix-assisted laser desorption ionization–time of flight mass spectrometry and cydB real-time quantitative PCR

Incorrect identification of Staphylococcus spp. can have serious clinical and zoonotic repercussions. Accordingly, the aim of this study was to determine if matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) and/or cydB real- time quantitative PCR (qPCR) could be used to accurately identify coagulase negative Staphylococcus spp. (CoNS) obtained from buffalo milk and milking environment samples. Seventy-five of 84 CoNS isolates could be identified to the species level (score value >1.99) using MALDI-TOF MS. However, as determined by cytochrome d ubiquinol oxidase subunit II (cydB) qPCR and by 16S RNA and cydB gene sequencing, 10S. agnetis strains were wrongly identified as S. hyicus by MALDI-TOF MS. In addition, 9 isolates identified by MALDI-TOF only to the genus level (score values between 1.70 and 1.99) could be identified to species by cydB qPCR. Our findings suggest that MALDI-TOF MS is a reliable method for rapid identification of S. chromogenes and S. epidermidis (species of interest both in human and veterinary medicine) and may be able to correctly identify other Staphylococcus spp. However, at present not all Staphylococcus spp. found in buffalo milk can be accurately identified by MALDI-TOF MS and for these organisms, the cydB qPCR developed in the current study may provide a reliable alternative method for rapid identification of CoNS species.

Significant Reduction of Blood Culture Contamination in the Emergency Department (ED) Using the Steripath® Blood Diversion Device

BackgroundContaminated blood cultures are a particular problem in EDs and often lead to unnecessary antibiotic treatment. A potential approach to reduce contamination is to discard the initial aliquot of blood which is often contaminated with skin plugs and bacteria. To test this approach, we performed a study using the Steripath® (SP) device (Magnolia Medical Technologies, WA) a pre-assembled, sterile blood culture system designed to divert the initial 1.5–2.0 mls of blood prior to bottle inoculation.MethodsThis was a pre-post intervention study conducted in the ED at Rush University Medical Center, Chicago. During the pre-intervention phase (1 September to 30 November 2015), 2 sets of peripheral blood cultures were collected using standard aseptic technique by nurses in the ED. Skin antisepsis was performed with ChloraPrep® and 5–10 mls of blood was inoculated into BacT Alert SA and SN bottles (Biomerieux). During the intervention phase (1 February to 1 May 2016), blood cultures were collected using the SP device. All bottles were incubated for 5 days and rates of blood culture contamination were compared between control and intervention periods.ResultsClassification of blood culture contamination was based on standard CLSI criteria. During the control phase, 929 sets of blood cultures were collected in the ED. A total of 40/929 sets (4.3%) from 36 patients were identified as contaminations and 81 sets (8.7%) from 51 patients were identified as true bacteremia. The contaminants included: 29 sets (72.5%) coagulase negative Staphylococcus spp. (CoNS), 4 sets (10%) Micrococcus spp., 3 sets (7.5%) Corynebacterium spp., 2 sets (5%) alpha-hemolytic Streptococci spp., 1 set (2.5%) each Bacillus spp. and E. faecium. During the intervention phase, 3/539 (0.6%) sets of blood cultures from 3 patients were contaminated (P < 0.001). The 3 contaminants were 1 CoNS, 1 alpha-hemolytic Streptococcus spp. and 1 Corynebacterium spp. 49 sets (9.1%) from 35 patients were identified as true bacteremia.ConclusionThe use of the SP device in the ED over a 3-month period significantly reduced the rate of blood culture contamination from 4.3% to 0.6% while the rates of true bacteremia remain unchanged. The SP device represents a simple and effective method for reducing blood culture contaminationDisclosures All authors: No reported disclosures.

Multicenter Study of the Clinical Presentation of Staphylococcus lugdunensis Bacteremia in Japan.

Staphylococcus lugdunensis (SL) is a bacterium with a highly pathogenicity than most other coagulase-negative Staphylococcus spp. (CoNS). In Japan, data on this pathogen are sparse, and the current prevalence of SL bacteremia is unknown. Therefore, we investigated the prevalence of SL in blood culture specimens in a prospective multicenter study across 5 facilities. A total of 3,284 patients had positive blood cultures, and 2,478 patients had bacteremia. Among the patients with bacteremia, 7 patients (0.28%) had SL bacteremia. A total of 281 patients had CoNS bacteremia, with SL accounting for 2.49% of these cases. Of the 7 patients with SL bacteremia, 1 patient (14.3%) had infective endocarditis, and 1 patient (14.3%) died within 30 days. In this study, SL resulted in the development of bacteremia in select patients. Clinicians in Japan should be aware of the prevalence of SL and the complications of SL bacteremia.

Study of Antibacterial Activity of Ethylacetate Total Extract and the Alkaloid Fraction from Flowering Aerial Parts of Glaucium vitellinum Boiss. et Buhse against Clinical Isolates of Staphylococcus Spp.

Background: The purpose of this study was evaluation of the antimicrobial effect of ethyl acetate extract and alkaloid fraction of Glaucium vitellinum (G. vitellinum) against clinical Staphylococcus spp. isolates from patients of Sina hospital of Tehran. M aterials and Methods: The plant of G. vitellinum was collected from Khonsar, Isfahan province, during May 2014. It’s flowering and aerial parts were washed, dried, powdered and extracted with methanol and ethyl acetate by using percolator apparatus, separately. In continuation, the alkaloid fraction was separated from metanolic total extract. 100 clinical isolates of Staphylococcus spp . were collected randomly from different clinical samples of patients who referred to Sina hospital of Tehran during 2013-2014. Also, their resistant to common antibiotics were evaluated by disk diffusion method based on the CLSI 2014 protocol. Continuously, the antibacterial effect of ethyl acetate total extract and the alkaloid fraction against clinical isolates of Staphylococcus spp . were evaluated by determining the minimal inhibitory concentration (MIC) by microdilution method based on the CLSI 2014. Standard Staphylococcus aureus (PTCC1431) and Staphylococcus epidermidis (PTCC 1435) were evaluated, simultaneously. R es ults: Based on the results, 93% of isolates were coagulase positive and 7% were coagulase negative Staphylococci spp. (CoNS). All coagulase positive cocci were identified as Staphylococcus aureus and among 7% CoNS, 3% were identified as S. epidermidis , so, in the follow they are named only CoNS. The MIC of alkaloid fraction of G.vitellinum was: 17.87 mg/ml and 23.21 mg/ml against coagulase positive S.aureus and CoNS isolates , respectively . Also, MIC of ethyl acetate total extract of G.vitellinum was: 73.25 mg/ml and 98.21mg/ml on coagulase positive S. aureus and CoNS isolates, respectively . 61.29% of clinical S. aureus isolates were sensitive to ethyl acetate total extract and 100 % were sensitive to alkaloid fraction while 100% were penicillin resistant while only 60% of them were Trimethoprim/sulfamethoxazole (SXT) sensitive. Similarly, among CoNS isolates, 42.85% and 100% were sensitive to ethyl acetate total extract and alkaloid fraction, respectively. While 100% were penicillin resistant and only 42%were ciprofloxacin and doxycycline sensitivity. C onclusion: based on the existence of good antibacterial effect for alkaloid portion of G. vitellinum against clinical isolates of Staphylococcus spp. doing other in vitro and in vivo complementation tests are recommended for the further studies. Keyword: Glaucium vitellinum , Anti bacterial, Alkaloids, Papaveraceae