Majority Of Coagulase-negative Staphylococci Research Articles

Bloodstream Infection Due to Coagulase-Negative Staphylococci: Impact of Species on Prevalence of Infective Endocarditis.

(1) Background: Coagulase-negative staphylococci (CoNS) are an important group of organisms that can cause bloodstream infection (BSI) and infective endocarditis (IE). The prevalence of IE in patients with BSI due to different CoNS species, however, has received limited attention; (2) Methods: A retrospective study of adults with monomicrobial CoNS BSI who had undergone echocardiography and a risk factor analysis was done to determine the most common CoNS species that cause definite IE; (3) Results: 247 patients with CoNS BSI were included in the investigation; 49 (19.8%) had definite IE, 124 (50.2%) possible IE, and 74 (30.0%) BSI only. The latter two entities were grouped in one category for further analysis. The most common species in CoNS BSI was Staphylococcus epidermidis (79.4%) and most patients (83.2%) had possible IE/BSI only. 59.1% of patients with BSI due to S. lugdunensis had definite IE. The majority of CoNS were healthcare-associated/nosocomial bacteremia. Multivariable analysis demonstrated that valve disease (p = 0.002) and a foreign cardiovascular material (p < 0.001) were risk factors associated with definite IE. Patients with S. lugdunensis BSI had an 8-fold higher risk of definite IE than did those with S. epidermidis BSI and nearly a 13-fold higher risk than did patients with BSI due to other species of CoNS (p = 0.002); (4) Conclusions: The prevalence of definite IE in patients with BSI due to different CoNS species was significant. CoNS bacteremia, particularly with S. lugdunensis, confers a significant risk of IE, particularly in patients with a valve disease or intravascular foreign body material and should not be immediately dismissed as a contaminant.

Oropharyngeal Pathogenic Bacteria: Carriage, Antimicrobial Susceptibility Pattern and Associated Risk Factors among Febrile Patients

Background: Pharyngeal and respiratory infections due to bacteria are global concerns especially because of the emergence of multi-drug resistant strains. The Oropharynx is one of the regions of the human body that is heavily colonized by microbial flora. So, the Oropharyngeal carriage is a major risk factor for an invasion and developing the disease. Therefore, this study was aimed at determining the carriage rate of potential pathogenic Oropharyngeal bacteria, associated risk factors, and antimicrobial susceptibility patterns among febrile patients at AHMC. Methods: A Cross-sectional study was conducted from November 2018 to April 2019. A systematic random technique was implemented to collect Oropharyngeal samples from 253 selected febrile patients. Specimen collection and processing were done following standard bacteriological procedures in Adama Public Health, Research, and Referral Laboratory. Antimicrobial susceptibility testing was done using the disk diffusion method in accordance with the Clinical and Laboratory Standard Institutes guideline. Data were analyzed using SPSS version 20. Results: Overall oropharyngeal bacteria carriage rate was 75.1%. A total of 190 bacterial organisms were isolated with 96 Coagulase-Negative Staphylococci (CNS), 55 Streptococcus pyogenes, and 19 Staphylococcus aureus were dominant isolates among gram-positive. Klebsiella pneumoniae, Neisseria meningitides, Moraxella catarrhalis, and Escherichia coli were among gram-negative bacteria isolates. Living in urban, cigarette smoking, and poor oral hygiene was significantly associated with the Oropharyngeal bacterial carriage rate. The majority of CNS, S.aureus, and S. pyogenes were resistant to different classes of antibiotics. Conclusion: Potentially pathogenic Oropharyngeal bacterial colonization rate was high. Place of living and behavioral factors are risk factors that were associated with bacterial colonization of the oropharynx. Several bacterial isolates were resistant to frequently prescribed antibiotic classes. Therefore, determining the antimicrobial susceptibility pattern of the isolates is important to intervene and prevent the risk of infection and also the emergence of multiple drug-resistant strains and disease management.

Antimicrobial resistance in coagulase-negative staphylococci isolated from subclinical mastitis in Ettawa Crossbred goat (PE) in Yogyakarta, Indonesia

Abstract. Suwito W, Nugroho WS, Wahyuni AETH, Sumiarto B. 2021. Antimicrobial resistance in coagulase-negative staphylococci isolated from subclinical mastitis in Ettawa Crossbred goat (PE) in Yogyakarta, Indonesia. Biodiversitas 22: 3418-3422. Subclinical mastitis (SCM) in Ettawa Crossbred Goat (PE) is most frequently caused by staphylococci with a significant reduction in milk yield. The aim of this study is to determine antimicrobial resistance patterns of coagulase-negative staphylococci (CoNS) from PE goat SCM. A total of 36 CoNS isolates originating from PE goat SCM were collected in semisolid tube use in this study. All CoNS isolates were further examined for antimicrobial susceptibility testing by the Kirby-Bauer disc diffusion method. Antibiotic susceptibility of CoNS isolated samples according to Clinical Laboratory Standards Institute (CLSI). The CoNS isolates showed the highest resistance rate against sulfamethoxazole (65%), ampicillin (55.56%), penicillin (45%), cefoxitin (33.33%), erythromycin (25%), oxytetracycline (20%), tetracycline (15%), gentamicin and neomycin (11.11%), while oxacillin was sensitive. The highest of multiple antimicrobials resistance observed 15% in ampicillin, penicillin and tetracycline, then 5-10% in ampicillin, penicillin, erythromycin, tetracycline and oxytetracycline. The majority of CoNS in this study were resistant to sulfamethoxazole and then, followed by ampicillin, penicillin, cefoxitin, erythromycin, oxytetracycline, tetracycline, gentamicin and neomycin. In addition, most isolates were penicillin-resistant and multidrug-resistant (MDR).

Evaluation of three rapid methods for the direct identification of Staphylococcus aureus from positive blood cultures.

Staphylococci represent the most commonly encountered blood culture isolates. Differentiating Staphylococcus aureus from coagulase-negative staphylococci (CoNS) is important in guiding empirical therapy, especially since the majority of CoNS are contaminants. This study evaluated three rapid methods for the direct identification of S. aureus from blood cultures. A total of 157 patient blood cultures with gram stains showing gram-positive cocci in clusters were included. The following assays were evaluated: API RAPIDEC staph (API) (bioMerieux, Durham, N.C.), the tube coagulase test (TCT) read at 4 h, and peptide nucleic acid (PNA) fluorescence in situ hybridization (FISH) (AdvanDx, Woburn, Mass.). All assays yielded results of S. aureus or non-S. aureus. The direct rapid results were compared to results obtained with isolated colonies using the AccuProbe Staphylococcus aureus Culture Identification Test (Gen-Probe, San Diego, Calif.). API, TCT, and PNA FISH exhibited sensitivities of 96, 84, and 99% and specificities of 99, 100, and 100%, respectively. Direct identification testing by any of these three assays yielded acceptable performance and timely results. This ability to accurately detect S. aureus in blood cultures gives the physician information with which to initiate or tailor antimicrobial therapy. Coupled with direct susceptibility testing of positive blood culture broths, the patient and institution may experience improved outcomes.

Dynamics of coagulase-negative staphylococcal colonization in patients and employees in a surgical intensive care unit

Because there is little information about the frequency of carriage of various species of coagulase-negative staphylococci (CNS) in hospitalized patients and the possible connection of these organisms with hospital staff, we prospectively investigated nasal CNS in patients and personnel in a Surgical Intensive Care Unit (SICU). The majority of CNS from personnel were Staphylococcus epidermidis. The CNS species from patients on admission were more diverse and included multiply antibiotic-resistant S. haemolyticus. Patients' CNS became more like CNS colonizing personnel after admission with respect to both antimicrobial susceptibility and speciation. Plasmid and antibiotic sensitivity profiles of S. epidermidis resistant to multiple antibiotics from five patients were identified as those from one employee, but there was no evidence that this was of clinical significance. A variety of factors influence nasal colonization by CNS in SICUs. The nasal CNS of patients change after admission and may become more resistant and less diverse. The factors influencing changes in the antibiotic susceptibility and the aetiology of CNS infection require further study.

A bacteriological study of otitis media with effusion. Concurrent coagulase-negative staphylococcal infections in the middle ear.

We investigated the bacteriology of 50 chronic middle ear effusions from 30 children (mean age, 5 years 4 months) and compared this with the microorganisms present in the external ear canals and adenoids of each patient to distinguish pure middle ear bacteria from probable contaminations. Coagulase-negative staphylococci (CS), formerly considered to be non-pathogens, were the most frequently isolated bacteria in the middle ear effusions and were followed in incidence by alpha-hemolytic streptococci and group D streptococci. CS were found in 24% of all effusions and in 44% of the infected effusions. Most of the CS strains belonged to the species of Staphylococcus epidermidis. Although the majority of CS isolated from the middle ear effusions studied proved not to be contaminants, the populations of CS in the middle ear and external ear canal showed similar biochemical reaction patterns, antimicrobial susceptibilities, and in vitro production of mucus. No correlation was found between the bacteria present in adenoidal tissue and middle ear effusions.

Distribution of coagulase-negative staphylococci in human infections

One hundred and twenty strains of coagulase-negative staphylococci isolated from hospitalized patients during a period of one year were classified according to the scheme of Shleifer and Kloos. Thermostable deoxyribonuclease was detected in two strains designated as Staphylococcus aureus, coagulase-negative. Staphylococcus epidermidis was isolated most frequently from all cases of clinical material, with Staph. saprophyticus and Staph. hominis in second place in cases of urinary tract infection and septicaemia. Other coagulase-negative staphylococci, including strains of Staph. haemolyticus, Staph. capitis, Staph. warneri, Staph. simulans, Staph. xylosus and Staph. aureuus, coagulase-negative, together with untypable strains were isolated from various clinical sources at a much lower frequency. About half of all strains were found to be resistant to penicillin G, streptomycin and tetracycline. With some exceptions, the majority of coagulase-negative staphylococci were sensitive to methicillin, cephalexin, cephapyrin, gentamicin and cotrimoxazole. Methicillin-resistant Staph. epidermidis, Staph. saprophyticus, Staph. hominis and untypable strains were also resistant to cephalexin and cephapyrin.

A SELECTIVE MEDIUM FOR THE ISOLATION AND ENUMERATION OF COAGULASE POSITIVE STAPHYLOCOCCI FROM FOODS

SUMMARYA medium is described for the isolation and enumeration of coagulase positive staphylococci from food products. It was based on the observation that coagulase positive staphylococci produced a zone of clearing in egg yolk emulsion suspended in an agar medium. In conjunction with a modified coagulase test most coagulase positive staphylococci can be confirmed within 24 hr. The majority of coagulase negative staphylococci produced no clearing; when present it was frequently accompanied by a precipitation zone within the clearing area. Sodium azide was used as a selective agent.