Objective: To investigate the prevalence and poor prognosis of late-onset sepsis (LOS) in very low birth weight infant (VLBWI). Methods: This prospective, multicenter observational cohort study was conducted based on the data from Sina-Northern Neonatal Network (SNN). The general data, perinatal information and poor prognosis of 6 639 VLBWI, who were admitted to the 35 neonatal intensive care units from 2018 to 2021, were collected and analyzed. According to the occurrence of LOS during hospitalization, the VLBWI were assigned to the LOS group and non-LOS group. The LOS group was further divided into 3 subgroups according to the occurrence of neonatal necrotizing enterocolitis (NEC) and purulent meningitis. The Chi-square test or Fisher exact probability method, independent sample t test, Mann-Whitney U test and multivariate Logistic regression model were used to analyze the relationship between LOS and poor prognosis in VLBWI. Results: A total of 6 639 eligible VLBWI were enrolled, including 3 402 cases (51.2%) of males and 1 511 cases (22.8%) with LOS. The incidences of LOS in extremely low birth weight infants (ELBWI) and extremely preterm infants were 33.3% (392/1 176) and 34.2% (378/1 105), respectively. There were 157 cases (10.4%) who died in the LOS group and 48 cases (24.9%) in the subgroup of LOS complicated with NEC. Multivariate Logistic regression analysis showed that LOS complicated with NEC was associated with increased mortality and incidence of grade Ⅲ-Ⅳ intraventricular hemorrhage (IVH) or periventricular leukomalacia (PVL), moderate or severe bronchopulmonary dysplasia (BPD), and extrauterin growth retardation (EUGR) (OR_adjust=5.27, 2.59, 3.04, 2.04; 95%CI 3.60-7.73, 1.49-4.50, 2.11-4.37, 1.50-2.79; all P<0.01); LOS complicated with purulent meningitis was also associated with increased mortality and incidence of grade Ⅲ-Ⅳ IVH or PVL, and moderate or severe BPD (OR_adjust=2.22, 8.13, 3.69, 95%CI 1.30-3.37, 5.22-12.67, 2.49-5.48; all P<0.01); the infants without NEC or purulent meningitis in the LOS group was only associated with increased incidence of moderate or severe BPD (OR_adjust=2.20, 95%CI 1.83-2.65, P<0.001). After ruling out contaminated bacteria, a total of 456 cases showed positive blood culture, including 265 cases (58.1%) of Gram-negative bacteria, 126 cases (27.6%) of Gram-positive bacteria, and 65 cases (14.3%) of fungi. The most common pathogenic bacteria was Klebsiella pneumoniae (n=147, 32.2%), followed by coagulase-negative Staphylococcus (n=72, 15.8%) and subsequently Escherichia coli (n=39, 8.6%). Conclusions: The incidence of LOS is high in VLBWI. Klebsiella pneumoniae is the most common pathogenic bacteria, followed by coagulase-negative Staphylococcus and Escherichia coli. LOS is associated with a poor prognosis for moderate to severe BPD. The prognosis of LOS complicated with NEC is poor with the highest mortality, and the risk of brain damage is significantly increased when LOS complicated with purulent meningitis.
Infant ; Male ; Female ; Pregnancy ; Infant, Newborn ; Humans ; Prospective Studies ; Coagulase ; Infant, Extremely Low Birth Weight ; Sepsis/epidemiology* ; Bronchopulmonary Dysplasia ; Escherichia coli ; Infant, Extremely Premature ; Meningitis

Objective:To investigate the etiological characteristics of nasal bacterial infection in patients with nasal lymphoma. Methods:The results of bacterial culture of nasal secretions from 39 healthy people and 86 patients with nasal lymphoma in the Affiliated Hospital of Qingdao University from January 2019 to June 2022 were retrospectively analyzed, and the differences in nasal bacteria distribution between nasal lymphoma and healthy people were analyzed and compared. Results:Corynebacterium（38.90%） was the most common bacteria in the nasal cavity of healthy people, followed by coagulase-negative Staphylococcus（31.95%）, Staphylococcus epidermidis（15.28%） and Staphylococcus aureus（6.95%）. The most common bacteria in nasal lymphoma patients was Staphylococcus aureus（30.37%）, followed by Corynebacterium（9.63%）, Staphylococcus epidermidis（7.41%） and coagulase negative Staphylococcus（6.67%）. A total of 81 nasal lymphoma patients were detected with bacteria, positive rate is as high as 94.19%（81/86）. Conclusion:Staphylococcus aureus is the main pathogenic bacteria in nasal secretion of patients with nasal lymphoma, which provides guiding significance for the clinical prevention and treatment of nasal lymphoma complicated with infection or not.
Humans ; Retrospective Studies ; Coagulase ; Nasal Cavity ; Bacteria ; Staphylococcus aureus ; Rhinitis/complications* ; Staphylococcal Infections

OBJECTIVES: Staphylococcus aureus is a nosocomial pathogen that provides a major challenge in the healthcare environment, especially in burns units where patients are particularly susceptible to infections. In this study, we sought to determine molecular types of S. aureus isolates collected from burns patients, based on staphylococcal protein A and coagulase gene polymorphisms. METHODS: Antibiotic susceptibility testing of 89 S. aureus strains isolated from burn wounds of patients was assessed using the Kirby-Bauer disk diffusion method. Strains were characterized by spa typing, coa typing, and resistance and toxin gene profiling. RESULTS: A total of 12 different spa types were identified with the majority being t790 (18%). Panton-Valentine leucocidin encoding genes were identified in spa types t044 (5.6%), t852 (2.2%) and t008 (2.2%). The most commonly detected antibiotic resistance gene was ant (4′)-Ia (60.7%). Ten different coa types were detected and the majority of the tested isolates belonged to coa III (47.2%). All the high-level mupirocin-resistant and low-level mupirocin resistant strains belonged to coa type III. CONCLUSION: The present study illustrated that despite the high frequency of coa III and spa t790 types, the genetic background of S. aureus strains in Iranian burns patients was diverse. The findings obtained are valuable in creating awareness of S. aureus infections within burns units.
Ants ; Burns ; Coagulase ; Delivery of Health Care ; Diffusion ; Drug Resistance, Microbial ; Genetic Background ; Humans ; Leukocidins ; Methicillin Resistance ; Methicillin ; Methicillin-Resistant Staphylococcus aureus ; Methods ; Microbial Sensitivity Tests ; Mupirocin ; Staphylococcal Protein A ; Staphylococcus aureus ; Staphylococcus ; Wounds and Injuries

PURPOSE: To analyze clinical aspects in a cohort of patients with Staphylococcus keratitis according to coagulase positivity (coagulase negative Staphylococcus [CNS], coagulase positive Staphylococcus [CPS]). METHODS: Epidemiology, predisposing factors, clinical characteristics, treatment outcomes, and antibiotic susceptibility were comparatively analyzed in 138 cases of culture-proven Staphylococcus keratitis (94 eyes with CNS and 44 eyes with CPS) over 20 years (1998–2017) at Yeungnam University Hospital. Poor clinical outcomes were defined as a final corrected visual acuity <0.1, a decreased visual acuity after treatment, complications, or surgical treatment. Risk factors for poor clinical outcomes were evaluated in the total cohort and analyzed using multivariate logistic regression. RESULTS: The most common predisposing factors were corneal trauma in the CNS group (47.9%) and previous ocular surface disease in the CPS group (31.8%). No significant differences were observed in mean age, sex, previous ocular surface disease, epithelial defect size, and hypopyon between the two groups. Methicillin susceptibility (39.4% vs. 72.7%, p < 0.001) was significantly lower in the CNS group, and poor clinical outcomes (28.0% vs. 43.9%, p = 0.076) were more common in the CPS group. The significant risk factors for poor clinical outcomes were initial best-corrected visual acuity <0.1, epithelial defect size ≥ 5 mm², symptom duration ≥10 days, and hypopyon. CONCLUSIONS: No significant differences were observed in epidemiological factors and initial clinical characteristics between the two study groups, but predisposing factors and methicillin susceptibility differed between the two groups. Treatment outcomes were relatively worse in the CPS group than in the CNS group, but the difference was not statistically significant. Poor clinical outcomes were more associated with long symptom duration and poor initial clinical characteristics than with coagulase positivity.
Causality ; Coagulase ; Cohort Studies ; Corneal Injuries ; Epidemiology ; Humans ; Keratitis ; Logistic Models ; Methicillin ; Risk Factors ; Staphylococcus ; Visual Acuity

BACKGROUND: We evaluated the performance of the BD MAX StaphSR Assay (SR assay; BD, USA) for direct detection of Staphylococcus aureus and methicillin resistance not only in S. aureus but also in coagulase-negative Staphylococci (CNS) from positive blood cultures. METHODS: From 228 blood culture bottles, 103 S. aureus [45 methicillin-resistant S. aureus (MRSA), 55 methicillin-susceptible S. aureus (MSSA), 3 mixed infections (1 MRSA+Enterococcus faecalis, 1 MSSA+MRCNS, 1 MSSA+MSCNS)], and 125 CNS (102 MRCNS, 23 MSCNS) were identified by Vitek 2. For further analysis, we obtained the cycle threshold (Ct) values from the BD MAX system software to determine an appropriate cutoff value. For discrepancy analysis, conventional mecA/mecC PCR and oxacillin minimum inhibitory concentrations (MICs) were determined. RESULTS: Compared to Vitek 2, the SR assay identified all 103 S. aureus isolates correctly but failed to detect methicillin resistance in three MRSA isolates. All 55 MSSA isolates were correctly identified by the SR assay. In the concordant cases, the highest Ct values for nuc, mecA, and mec right-extremity junction (MREJ) were 25.6, 22, and 22.2, respectively. Therefore, we selected Ct values from 0-27 as a range of positivity, and applying this cutoff, the sensitivity/specificity of the SR assay were 100%/100% for detecting S. aureus, and 97.9%/98.1% and 99.0%/95.8% for detecting methicillin resistance in S. aureus and CNS, respectively. CONCLUSIONS: We propose a Ct cutoff value for nuc/mec assay without considering MREJ because mixed cultures of MSSA and MRCNS were very rare (0.4%) in the positive blood cultures.
Anti-Bacterial Agents/pharmacology ; Bacteremia/diagnosis/microbiology ; Coagulase/metabolism ; Humans ; Methicillin-Resistant Staphylococcus aureus/drug effects/genetics/*isolation & purification ; Microbial Sensitivity Tests ; Oxacillin/pharmacology ; Reagent Kits, Diagnostic ; Staphylococcus/drug effects/enzymology/genetics/isolation & purification ; Staphylococcus aureus/drug effects/genetics/*isolation & purification

OBJECTIVES: Integrons are thought to play an important role in the spread of antibiotic resistance. This study investigates class 1 and 2 integron-positive methicillin-resistant coagulase-negative staphylococci strains isolated in Iran and characterizes their patterns of antimicrobial resistance. METHODS: Hundred clinical isolates of coagulase-negative staphylococci were characterized for integron content and staphylococcal cassette chromosome mec (SCCmec) type. RESULTS: Sixteen isolates carried class 1 (intI1) integrons and four isolates carried class 2 (intI2) integrons. One resistance gene array was identified among the class 1 integrons (aadA1 cassette). The distribution of SCCmec types in 50 methicillin-resistant coagulase-negative staphylococci strains showed that SCCmec types III and V dominated among the tested strains. CONCLUSION: This is the first report of methicillin-resistant coagulase-negative staphylococci strains that carry two mobile genetic elements, including class 1 and 2 integrons and SCCmec, in Iran.
Coagulase* ; Drug Resistance, Microbial ; Integrons* ; Interspersed Repetitive Sequences ; Iran ; Methicillin Resistance*

Community-associated methicillin resistant Staphylococcus aureus (CA-MRSA) has become widespread in the community and healthcare settings, and a number of clonal lineages emerged on every country. Sequence type (ST) 80 clone of CA-MRSA was dominant in Europe and has increasingly been isolated from the Middle East but so far never found in Korea. In this study, 48 MRSA isolates recovered from ear infections were characterized by multilocus sequence typing (MLST), staphylococcal cassette chromosome mec (SCCmec) typing, staphylocoagulase (SC) genotyping, staphylococcal protein A gene (spa) typing, accessory gene regulator (agr) typing, and virulence gene profiling. Most MRSA strains belonged to three major clones: ST5-SCCmec II-SC type II (n=19, 39.6%), ST239-SCCmec III-SC type IV (n=15, 31.2%), and ST72-SCCmec IV-SC type Vb (n=11, 22.9%). Among the isolates, one strain was Panton- Valentine leukocidin (PVL)-positive ST80-SCCmec IV-SC type XIa - spa type t044-agr group III, and exfoliative toxin D-positive. This strain was susceptible to most antibiotics, but resistant to tetracycline and fusidic acid. This is the first report on the emergence of European ST80 CA-MRSA clone in Korea.
Anti-Bacterial Agents ; Busan* ; Clone Cells* ; Coagulase ; Delivery of Health Care ; Ear ; Europe ; Fusidic Acid ; Korea* ; Leukocidins ; Methicillin Resistance* ; Methicillin-Resistant Staphylococcus aureus* ; Middle East ; Multilocus Sequence Typing ; Staphylococcal Protein A ; Staphylococcus aureus ; Tetracycline ; Virulence

The molecular characteristics of methicillin-resistant Staphylococcus aureus (MRSA) isolated from neonates in a neonatal intensive care unit (NICU) were investigated by multilocus sequence typing (MLST), staphylocoagulase (SC) genotyping, staphylococcal cassette chromosome mec (SCCmec) typing, accessory gene regulator (agr) typing, and the presence of Panton-Valentine leukocidin (PVL). Among the 44 S. aureus isolates from nares in neonates between March and June 2014 at hospital in Busan, 27 (61.4%) were MRSA and 17 (38.6%) were methicillin-susceptible S. aureus (MSSA). The most prevalent clone in MRSA isolates was ST72-SC type Vb-SCCmec IV-agr I (n=26) and the remaining one was ST89-SC type I-SCCmec II-agr II. In MSSA isolates, the prevalent clone was ST121-SC type Va-agr IV (n=13), followed by ST72-SC type Vb-agr I (n=2), ST8-SC type III-agr I (n=1) and ST15-SC type X-agr II (n=1). All isolates did not possess the PVL. The data showed that the neonates in NICU carried high prevalence of ST72 MRSA and remarkably different clones with SC diversity between MRSA and MSSA isolates.
Busan ; Clone Cells ; Coagulase ; Humans ; Infant, Newborn ; Intensive Care, Neonatal* ; Leukocidins ; Methicillin Resistance* ; Methicillin-Resistant Staphylococcus aureus* ; Multilocus Sequence Typing ; Prevalence*

The prevalence and molecular characteristics of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) and methicillin-susceptible S. aureus (CA-MSSA) from children with skin infection were investigated by staphylocoagulase (SC) typing, multilocus sequence typing (MLST), SCCmec typing and virulent toxins, including Panton-Valentine leucocidin (PVL), and exfoliative toxins (ET). Among 69 cases of CA-S. aureus for a 3 month period from March to June, 2014 at hospital in Busan, 28 (40.6%) were MRSA and 41 (59.4%) were MSSA. Of the 28 CA-MRSA isolates, two major clones were identified as SC type Vb-ST72-SCCmec type IV (53.6%) and SC type l-ST89-SCCmec type II variant (42.8%), and the remaining one (3.6%) was SC type lll-ST8-SCCmec type IV. In CA-MSSA, the prevalent clone was SC type Vb-ST72 (29.3%), followed by SC type Vb-ST188 (21.9%), SC type Va-ST121 (19.5%) and SC type lV-ST30 (9.6%). None was positive for PVL gene, and all of the SC type l-ST89-SCCmec type II variant clones were ETB gene positive. The data suggest that there are significant clonal relatedness with specific SC types, and genetic diversities in both community strains isolated from children with skin infections.
Busan ; Child* ; Clone Cells ; Coagulase ; Exfoliatins ; Genetic Variation ; Humans ; Korea ; Leukocidins ; Methicillin Resistance* ; Methicillin-Resistant Staphylococcus aureus ; Multilocus Sequence Typing ; Prevalence ; Skin* ; Staphylococcus aureus*

Neonatal sepsis remains one of the most important causes of death and co-morbidity in very-low-birth-weight (VLBW) infants. The aim of this study was to determine the current incidences of early-onset sepsis (EOS) and late-onset sepsis (LOS), the distribution of pathogens, and the impact of infection on co-morbidities in VLBW infants. We analyzed the data including sepsis episode from 2,386 VLBW infants enrolled in Korean Neonatal Network from January 2013 to June 2014. We defined EOS as a positive blood culture occurring between birth and 7 days of life and LOS after 7 days of life. Sepsis was found in 21.1% of VLBW infants. The risk of sepsis was inversely related to birth weight and gestational age. EOS was found in only 3.6% of VLBW infants, however the mortality rate was as high as 34.1%. EOS was associated with the increased odds for bronchopulmonary dysplasia and intraventricular hemorrhage. The vast majority of EOS was caused by Gram-positive organisms, particularly coagulase-negative staphylococci (30.6%). LOS developed in 19.4% of VLBW infants with a 16.1% mortality rate. Pathogens in LOS were dominated by coagulase-negative staphylococci (38.3%). Twenty-five percent and fifty percent of first LOS episode occurred after 12 days and 20 days from birth, respectively. Younger and smaller VLBW infants showed the earlier occurrence day for the 25% of first LOS episode. This study provides a recent nationwide epidemiology of sepsis in VLBW infants in Korea. Based on this study, successful strategies to reduce infections would improve survival and reduce morbidity.
Coagulase/metabolism ; Databases, Factual ; Gestational Age ; Gram-Negative Bacteria/isolation & purification ; Gram-Positive Bacteria/isolation & purification ; Humans ; Incidence ; Infant, Newborn ; *Infant, Very Low Birth Weight ; Kaplan-Meier Estimate ; Republic of Korea/epidemiology ; Risk Factors ; Sepsis/*epidemiology/microbiology/mortality ; Staphylococcus/enzymology/isolation & purification