Prevalence of Complement-Mediated Cell Lysis-like Gene (sicG) in Streptococcus dysgalactiae subsp. equisimilis Isolates From Japan (2014–2016)

BACKGROUND: Streptococcus dysgalactiae subsp. equisimilis (SDSE; a β-hemolytic streptococcus of human or animal origin) infections are emerging worldwide. We evaluated the clonal distribution of complement-mediated cell lysis-like gene (sicG) among SDSE isolates from three central prefectures of Japan. METHODS: Group G/C β-hemolytic streptococci were collected from three institutions from April 2014 to March 2016. Fifty-five strains (52 from humans and three from animals) were identified as SDSE on the basis of 16S rRNA sequencing data.; they were obtained from 25 sterile (blood, joint fluid, and cerebrospinal fluid) and 30 non-sterile (skin-, respiratory tract-, and genitourinary tract-origin) samples. emm genotyping, multilocus sequence typing, sicG amplification/sequencing, and random amplified polymorphic DNA (RAPD) analysis of sicG-positive strains were performed. RESULTS: sicG was detected in 30.9% of the isolates (16 human and one canine) and the genes from the 16 human samples (blood, 10; open pus, 3; sputum, 2; throat swab, 1) and one canine sample (open pus) showed the same sequence pattern. All sicG-harboring isolates belonged to clonal complex (CC) 17, and the most prevalent emm type was stG6792 (82.4%). There was a significant association between sicG presence and the development of skin/soft tissue infections. CC17 isolates with sicG could be divided into three subtypes by RAPD analysis. CONCLUSIONS: CC17 SDSE harboring sicG might have spread into three closely-related prefectures in central Japan during 2014–2016. Clonal analysis of isolates from other areas might be needed to monitor potentially virulent strains in humans and animals.

Molecular Epidemiological Typing of Methicillin-Resistant Staphylococcus aureus Using Random Amplified Polymorphic DNA Analysis / 감염과화학요법

BACKGROUND: The random amplified polymorphic DNA (RAPD) analysis was investigated to see if this method could be a useful tool for monitoring of epidemic outbreaks of methicillin-resistant Staphylococcus aureus (MRSA) among patients and healthcare workers (HCW) in the intensive care units (ICU). METHODS: Thirty-eight MRSA strains were isolated from patients and HCW in Dong-A University Hospital ICU from October, 1998 to December, 1998 (10 patients and 8 HCW) and May, 2001 to July, 2001 (15 patients and 5 HCW). All strains were typed according to antimicrobial susceptibility and RAPD analysis patterns. mecA genes were detected using polymerase chain reaction (PCR). RESULTS: Twenty one of 25 (84%) and 12 of 13 (92%) MRSA, isolated from patients and HCW, respectively, were mecA positive. mecA positive MRSA were classified into 18 different types by RAPD analysis. CONCLUSION: DNA fingerprinting using RAPD analysis is a simple, effective, and rapid method for discriminating MRSA strains, and may be applicable in detecting outbreaks of S. aureus infections in the ICU.

Molecular Epidemiological Typing of Methicillin-Resistant Staphylococcus aureus Using Random Amplified Polymorphic DNA Analysis / 감염과화학요법

BACKGROUND: The random amplified polymorphic DNA (RAPD) analysis was investigated to see if this method could be a useful tool for monitoring of epidemic outbreaks of methicillin-resistant Staphylococcus aureus (MRSA) among patients and healthcare workers (HCW) in the intensive care units (ICU). METHODS: Thirty-eight MRSA strains were isolated from patients and HCW in Dong-A University Hospital ICU from October, 1998 to December, 1998 (10 patients and 8 HCW) and May, 2001 to July, 2001 (15 patients and 5 HCW). All strains were typed according to antimicrobial susceptibility and RAPD analysis patterns. mecA genes were detected using polymerase chain reaction (PCR). RESULTS: Twenty one of 25 (84%) and 12 of 13 (92%) MRSA, isolated from patients and HCW, respectively, were mecA positive. mecA positive MRSA were classified into 18 different types by RAPD analysis. CONCLUSION: DNA fingerprinting using RAPD analysis is a simple, effective, and rapid method for discriminating MRSA strains, and may be applicable in detecting outbreaks of S. aureus infections in the ICU.

Molecular typing of Helicobacter pylori by random amplified polymorphic DNA analysis in patients with gastroduodenal diseases / 대한내과학회지

BACKGROUND: Genetic diversity among Helicobacter pylori strains isolated from different patients has been debated. This study was undertaken to determine molecular types and genetic diversity among 20 isolates of H. pylori obtained from various gastroduodenal diseases, and also examined the association between molecular types of H. pylori and these diseases. METHODS: Antral biopsies were taken for culture from 38 patients with chronic gastritis, gastric ulcer and duodenal ulcer at the time of endoscopy. Biopsy specimens were primarily inoculated on chocolate agar and incubated microaerophilically at 37degree Cfor up to 7 days. H. pylori was identified by typical Gram stain morphology and biochemical tests. Random amplified polymorphic DNA (RAPD) fingerprinting was performed by 4 primers (OPA-07, 5'-GAAACGGGTG-3'; OPA-10, 5'-GTGATCGCAG-3'; OPA-11, 5'-CAATCGCCGT-3'; OPA-12, 5'-TCGGCGATAG-3'; Operon Technologies, Atlanta, GA). We used the NTSYS-pc (numerical taxonomy system and multivariate analysis system, version 1.50, Applied Biostatistics Inc., CA, USA) program to compose the phenogram for the differentiation of H. pylori strains. RESULTS: Twenty strains (52.6%) of H. pylori were isolated from 38 biopsy specimens. All isolates were divided into five molecular types (I-V) at similarity (S) value of 0.63; 7 strains (35%), 4 strains (20%), 4 strains (20%), 3 strains (15%) and 2 strains (10%) belonged to type II, III, IV, V and I, respectively. The distribution of genetic S value was 0.24 to 0.91 in all isolates, thus the isolates had a wide range of S values. The mean S values of all isolates, type I, II, III, IV and V were 0.69, 0.69, 0.73, 0.75 and 0.65, respectively. There was no specific correlation between molecular types and gastroduodenal diseases. CONCLUSION: H. pylori isolates had high level of genetic diversity. The RAPD molecular types of H. pylori were not disease-specific since the types were diverse in the isolates from various gastroduodenal diseases.

Molecular Epidemiology of Staphylococcus aureus Isolated in the Hospital Environments / 감염

BACKGROUND: This study was designed to investigate the isolation rate of Staphylococcus aureus from hands and nasal cavities of physicians and nurses and to determine the relationship between the isolates of S. aureus from patients with nosocomial infection and the isolates from physicians, nurses and the hospital environment. METHODS: Twenty-three S. aureus isolates which consisted of 8 strains from patients, 7 strains from doctors and nurses, 7 strains from hospital environments, and S. aureus ATCC 25923 were examined. Biochemical profile by the use of API Staph (API system, La Balme-Les Grottes, France), antibiogram by disk diffusion method, and random amplified polymorphic DNA analysis (RAPD) were used for the strain differentiation and molecular typing of S. aureus isolates. RESULTS: The isolation rate of S. aureus in hands and nasal cavities of doctors and nurses was 21% (25/ 120) and 28% (33/120), respectively. The isolation frequency of methicillin-resistant S. aureus (MRSA) from doctors, nurses, and hospital environments was 57% (8/ 14). The isolates disclosed 13 different biochemical profiles and 14 different resistant patterns of antimicrobials. All isolates were divided into five molecular types (A~E) by RAPD with a similarity (S) value of 0.55; 10 strains (45%) belonged to type A, 7 (32%) to type C, 3 (14%) to type B, one each to type D and E, respectively. The S value between strain 11 from hospital environments and strain 12 from a patient was 1.00, which means that they are the same on the genetic level. CONCLUSION: These findings reveal the existence of a close relationship between clinical isolates and isolates from hospital environment, including those from physicians and nurses. Thus, the implementation of an infection control programs to reduce the spread of MRSA within hospitals is important for the prevention of nosocomial infections.

Molecular Typing of Salmonella typhi by Random Amplified Polymorphic DNA Analysis / 대한임상미생물학회지

BACKGROUND: In the year 1996, there were some outbreaks of Salmonella typhi infection in Pusan and therefore, the incidence of S. typhi infection was markedly increased in comparison with the previous year. To differentiate the isolates epidemiologically, a random amplified polymorphic DNA(RAPD) fingerprinting method has been developed. METHODS: A total of 9 arbitrary primers were screened with S. typhi strains isolated in Pusan, 1996. This allowed selection of a panel of primers capable of detecting DNA polymorphisms among S. typhi isolates. This panel was used to examine 54 strains of S. typhi, which had been isolated in Pusan including the cases of outbreaks that was previously characterized by phage typing. RESULTS: Four single primers and one combination of two primers were selected to discriminate the S. typhi isolates. RAPD analysis resolved the 54 strains into 20 different subtypes. At least two outbreaks were found by RAPD analysis. The isolates of E1 phage type, which are the most common in Korea, were perfectly differentiated with each other, except the strains isolated within the outbreaks. CONCLUSION: The RAPD approach is the useful epidemiologic tool to S. typhi subtyping, which is providing high discriminatory power. There were at least two outbreaks when the epidemic Salmonella infections of Pusan in 1996 had been occurred. The primers or their comb ination capable to discriminate the S. typhi isolates were described.