Background: Escherichia coli (EC), Escherichia fergusonii (EF), and Citrobacter freundii (CF) are clinically significant Gram-negative bacteria that are difficult to differentiate because of their shared 16S rRNA gene sequences. Methods: This study presents a novel approach utilizing adenylate kinase (adk) gene polymerase chain reaction (PCR)-restriction fragment length polymorphism analysis for the precise discrimination of EC, EF, and CF. Analysis of adk sequences revealed unique restriction sites for BtsIMutI, BtgI, and AgeI restriction enzymes at nucleotide positions 93 and 96. Results: Theoretical predictions translated into distinct banding patterns during agarose gel electrophoresis following PCR/restriction digestion. Experimental validation with reference strains and clinical isolates, including 84 EC and CF strains, demonstrated the efficacy of this method for differentiating these species. Assay specificity was confirmed by selective digestion of adk amplicons with BtsIMutI for EC and AgeI for CF. Conclusion This molecular technique provides a rapid and accurate method to discriminate between closely related bacterial species and is promising for clinical diagnostics and epidemiological studies. Thus, our adk PCR/restriction digestion assay is a valuable tool for the advancement of bacterial typing methods for EC, EF, and CF, and contributes to the ongoing exploration of microbial diversity and epidemiology.

BACKGROUND: The purpose of this study was to evaluate the usefulness of sonication technique for microbiological diagnosis and the sterility of the recycled autoclaved femoral components from infected total knee arthroplasty (TKA) using a sonication method. METHODS: Nineteen femoral implants explanted from patients with infected TKA were sterilized with a standard autoclave method. Standard culture of the fluid before and after sonication of the sterilized implants was performed to detect pathogenic microorganisms. Additional experiments were performed to evaluate the sterility of the recycled implant by inducing artificial biofilm formation. Methicillin-resistant Staphylococcus aureus (MRSA) was inoculated into 10 implants and sterilization in a standard autoclave was performed, and then the fluid was cultured before and after sonication. RESULTS: Two of the 19 sterilized implants were positive for growth of bacteria after sonication, whereas no growth was detected in the cultured fluid from the sterilized implants before sonication. The bacteria were Staphylococcus species in all two cases. In one of 10 implants inoculated with MRSA, the culture was positive for growth of bacteria both before and after sonication. However, Staphylococcus epidermidis was cultured from both occasions and thus this implant was thought to be contaminated. CONCLUSIONS: We found sonication for identification of pathogens could be helpful, but this finding should be interpreted carefully because of the possibility of contamination. Sterilization of an infected femoral implant with an autoclave method could be a good method for using the temporary articulating antibiotic spacer in two-stage revision arthroplasty.
Arthroplasty ; Arthroplasty, Replacement, Knee* ; Bacteria ; Biofilms ; Diagnosis ; Humans ; Infertility* ; Methicillin-Resistant Staphylococcus aureus ; Methods* ; Sonication* ; Staphylococcus ; Staphylococcus epidermidis ; Sterilization

Propionibacterium acnes, a gram-positive, anaerobic, and aerotolerant bacterium that is found frequently in the skin as part of the human microbiome causes inflammatory acne, shoulder infection, and the contamination of medical devices. The study goals were the antibiotic resistant and molecular epidemiological characterization of the P. acnes isolates in Korea. A total of 22 P. acnes isolates originated from diverse patients were obtained from three National Culture Collections for Pathogens in South Korea. The hemolytic properties and minimum inhibitory concentrations (MIC) of five antibiotics (tetracycline, doxycycline, clindamycin, erythromycin, and minocycline) were determined. Only one isolate showed high MIC values and resistance to all five antibiotics. Genotypic characterization was achieved by multilocus sequence typing (MLST) for eight loci (aroE, guaA, tly, camp2, atpD, gmk, lepA, and sodA) and repetitive-sequence-based PCR (rep-PCR) analysis using the DiversiLab kit. MLST revealed four phylogroups that were type IA₁ (27.3%), type IA₂ (18.2%), type IB (13.6%), and type II (40.9%). Rep-PCR results demonstrated three clusters that were cluster I (39.1%), cluster II (45.5%), and cluster III (13.6%). The isolates of cluster I were part of phylogroup type IA (both IA₁ and IA₂), and the isolates of cluster II belonged to phylogroup type II. All isolates of phylogroup type IB were hemolytic and belonged to cluster III. The results of rep-PCR clustering analysis showed a good correlation with those of MLST phylogroups, suggesting that rep-PCR could be an alternative method to track P. acnes subtype lineages.
Acne Vulgaris ; Anti-Bacterial Agents ; Clindamycin ; Doxycycline ; Erythromycin ; Humans ; Korea ; Methods ; Microbial Sensitivity Tests ; Microbiota ; Multilocus Sequence Typing* ; Polymerase Chain Reaction* ; Propionibacterium acnes* ; Propionibacterium* ; Shoulder ; Skin

The goal of this research was to determine the relationship between the stage of chronic periodontitis and the presence of six bacterial pathogens (Aggregatibacter actinomycetemcomitans: AA, Fusobacterium nucleatum: FN, Porphyromonas gingivalis: PG, Prevotella intermedia: PI, Enterococcus faecalis: EF, and Parvimonas micra: PM). Forty-six chronic periodontitis patients visiting a dental hospital were included in this investigation. They were classified into four chronic periodontitis stages based on the sulcus bleeding index value and the probing depth. The tissue samples from the periodontal surgery were used for a direct PCR detection assay. A total of 49 samples from 46 patients were collected and classified into four chronic periodontitis groups (N: 6, P1: 13, P2: 18, P3: 12). The PCR assay showed that FN, PI, and PM were involved from the beginning of chronic periodontitis (P1), while AA and PG existed regardless of the disease stages. EF was strongly linked to the P3 stage of the disease. In order to assess the effect of dental treatments on patients with chronic periodontitis, EF should be a critical marker for P3 patients, while FN, PI, and PM would be good indicators for chronic periodontitis.
Chronic Periodontitis* ; Enterococcus faecalis ; Fusobacterium nucleatum ; Hemorrhage ; Humans ; Polymerase Chain Reaction ; Porphyromonas gingivalis ; Prevotella intermedia

Salmonella enterica serovar Enteritidis is one of the major food borne pathogens. Utilizing lytic bacteriophages against this pathogen can be a new and effective approach for the prevention of food-contamination and food-borne infection. In this study, we isolated and characterized a Salmonella Enteritidis specific lytic bacteriophage (phage SE2). The bacteriolytic activity of planktonic and biofilmed cells against an antibiotic resistant strain of Salmonella Enteritidis was also evaluated. Phage SE2 revealed an efficient bacteriolytic effect with biofilm dispersing ability and could maintain its virulence even at extreme pH and temperature. It can be a potential biotherapeutic agent against Salmonella Enteritidis.
Bacteriophages ; Biofilms ; Drug Resistance ; Hydrogen-Ion Concentration ; Plankton ; Salmonella ; Salmonella enterica ; Salmonella enteritidis ; Sprains and Strains

Salmonella enterica has been one of the most widespread foodborne pathogens in Korea. Between 1998 and 2007, a total of 9,472 Salmonella isolates were identified from foodborne and waterborne illness patients. During that time, Korea was transitioning into a developed country in industry as well as in its hygiene system. Although the isolation number of total Salmonella including serovar Typhi has decreased since 1999, the isolation of rare Salmonella serovars has emerged. Three most prevalent serovars during 1998-2007 were S. enterica Typhi, S. enterica Enteritidis, and S. enterica Typhimurium. There were remarkable outbreaks caused by rare serovars such as S. enterica Othmarschen, S. enterica London and S. enterica Paratyphi A, and overseas traveler-associated infections caused by S. enterica Weltevreden and S. enterica Anatum. Salmonella serovars from overseas travelers made a diverse Salmonella serovar pool in Korea. This study is the first review of the status of the human Salmonella infection trend in a developing country during 1998-2007. Newly emerging rare Salmonella serovars should be traced and investigated to control new type pathogens in the developed world.
Food Microbiology ; Humans ; Republic of Korea ; Salmonella/classification/genetics/*isolation & purification ; Salmonella Infections/epidemiology/etiology/*microbiology ; Serotyping ; Water Microbiology

Salmonellae have been recognized as uncommon etiological organisms causing osteomyelitis in patients with sickle cell anemia and other immunocompromised conditions. A 34-year old man who had no underlying illness except for congenital block vertebrae at T10-11 vertebrae was admitted to the hospital due to lower back pain and fever for a week. Vertebral osteomyelitis was diagnosed and surgical drainage was performed. Salmonella enterica serovar Othmarschen was isolated from the drained pus. Therapy with ciprofloxacin for 8 weeks was successful without relapse. We describe here a case of vertebral osteomyelitis which was caused by S. Othmarschen in an immunocompetent patient.
Anemia, Sickle Cell ; Ciprofloxacin ; Drainage ; Fever ; Humans ; Low Back Pain ; Osteomyelitis ; Recurrence ; Salmonella ; Salmonella enterica ; Spine ; Suppuration

Salmonellae have been recognized as uncommon etiological organisms causing osteomyelitis in patients with sickle cell anemia and other immunocompromised conditions. A 34-year old man who had no underlying illness except for congenital block vertebrae at T10-11 vertebrae was admitted to the hospital due to lower back pain and fever for a week. Vertebral osteomyelitis was diagnosed and surgical drainage was performed. Salmonella enterica serovar Othmarschen was isolated from the drained pus. Therapy with ciprofloxacin for 8 weeks was successful without relapse. We describe here a case of vertebral osteomyelitis which was caused by S. Othmarschen in an immunocompetent patient.
Anemia, Sickle Cell ; Ciprofloxacin ; Drainage ; Fever ; Humans ; Low Back Pain ; Osteomyelitis ; Recurrence ; Salmonella ; Salmonella enterica ; Spine ; Suppuration