Among gram-negative bacteria, rate of antibiotic resistance has been increasing. As a result, carbapenem is now considered as a last resort of therapeutic regimens for gram-negative bacterial infections. The choice of antibiotics has been impeded by the spread of organisms producing metallo-beta-lactamases (MBL), which can confer resistance to nearly all beta-lactams. MBLs have extremely diverse structures and are carried by various organisms including human pathogens. This review will focus on the classification and current status of MBL reported in Korea.
Anti-Bacterial Agents ; beta-Lactams ; Drug Resistance, Microbial ; Gram-Negative Bacteria ; Gram-Negative Bacterial Infections ; Health Resorts ; Humans ; Korea

Cardiobacterium hominis, a fastidious gram-negative bacillus rarely causing endocarditis, was isolated from blood culture of a 41-year-old man with subacute bacterial endocarditis. The patient had undergone an operation of valve replacement 4 years before. Growth of the organism was only detected in 1 of 6 blood cultures after 7 days incubation. The isolate showed typical characteristics of C. hominis, i.e., tear-drop like cells and a weak positive indole reaction. The isolate was susceptible to many antimicrobial agents, but penicillin G and streptomycin therapy failed to cure the disease.
Adult ; Bacterial Infections/complications* ; Case Report ; Endocarditis, Subacute Bacterial/etiology* ; Gram-Negative Bacteria ; Human ; Male

BACKGROUNDThe Study for Monitoring Antimicrobial Resistance Trends program monitors the activity of antibiotics against aerobic and facultative Gram-negative bacilli (GNBs) from intra-abdominal infections (IAIs) in patients worldwide.

METHODSIn 2011, 1 929 aerobic and facultative GNBs from 21 hospitals in 16 cities in China were collected. All isolates were tested using a panel of 12 antimicrobial agents, and susceptibility was determined following the Clinical Laboratory Standards Institute guidelines.

RESULTSAmong the Gram-negative pathogens causing IAIs, Escherichia coli (47.3%) was the most commonly isolated, followed by Klebsiella pneumoniae (17.2%), Pseudomonas aeruginosa (10.1%), and Acinetobacter baumannii (8.3%). Enterobacteriaceae comprised 78.8% (1521/1929) of the total isolates. Among the antimicrobial agents tested, ertapenem and imipenem were the most active agents against Enterobacteriaceae, with susceptibility rates of 95.1% and 94.4%, followed by amikacin (93.9%) and piperacillin/tazobactam (87.7%). Susceptibility rates of ceftriaxone, cefotaxime, ceftazidime, and cefepime against Enterobacteriaceae were 38.3%, 38.3%, 61.1%, and 50.8%, respectively. The leastactive agent against Enterobacteriaceae was ampicillin/sulbactam (25.9%). The extended-spectrum β-lactamase (ESBL) rates among E. coli, K. pneumoniae, Klebsiella oxytoca, and Proteus mirabilis were 68.8%, 38.1%, 41.2%, and 57.7%, respectively.

CONCLUSIONSEnterobacteriaceae were the major pathogens causing IAIs, and the most active agents against the study isolates (including those producing ESBLs) were ertapenem, imipenem, and amikacin. Including the carbapenems, most agents exhibited reduced susceptibility against ESBL-positive and multidrug-resistant isolates.

Anti-Bacterial Agents ; pharmacology ; China ; Enterobacteriaceae ; classification ; drug effects ; genetics ; pathogenicity ; Gram-Negative Bacteria ; classification ; genetics ; Gram-Negative Bacterial Infections ; microbiology ; Humans ; Intraabdominal Infections ; microbiology ; Microbial Sensitivity Tests

Over the past decade, infections caused by antimicrobial-resistant bacteria have increased and continued to challenge physicians. Recent data show rapidly increasing rates of infection due to multidrug-resistant (MDR) gram-negative bacilli. Furthermore, pandrug-resistant infections now occur, especially due to gram-negative bacilli, and our therapeutic options for these pathogens are extremely limited. Infection caused by MDR bacteria was associated with a greater likelihood of inappropriate antimicrobial therapy, and inappropriate antimicrobial therapy has an adverse effect on survival in patients with serious infections. Consequently, it may be presumed that serious infections caused by MDR bacteria have a worse prognosis because of the delay in initiation of appropriate antimicrobial therapy. Empirical antibiotics for serious infections should be recommended on the basis of the distribution of pathogens and their susceptibility patterns in the institution where the regimen is administered. Therefore, physicians who are caring for patients with bacterial infection should be familiar with local antimicrobial susceptibility patterns and the epidemiology of MDR bacterial infections, in order to improve the treatment outcome of the patients. This comprehensive review aims to describe the epidemiology and clinical implications of MDR gram-negative bacterial infections in Korea, a country with a high prevalence of antimicrobial-resistant pathogens.
Anti-Bacterial Agents ; Anti-Infective Agents ; Bacteria ; Bacterial Infections ; Gram-Negative Bacterial Infections ; Humans ; Korea ; Prevalence ; Prognosis ; Treatment Outcome

Chromobacterium violaceum is a gram negative straight rod, 0.8-1.2 by 2.5 to 6.0 m, which is motile by one polar flagella and one to four lateral flagella. The organism inhabits soil and water and is often found in semitropical and tropical climates. Infections in humans are rare. We report a case of infection caused by strains of C. violaceum. A 38-year-old male patient was admitted to KyungHee University Hospital, Seoul, Korea on July 28th, 2003, after a car accident. The patient had multiple trauma and lacerations. He had an open wound in the left tibial area from which C. violaceum was isolated. The strain was resistant to ampicillin, tobramycin, ampicillin/sulbactam, ceftriaxone and cefepime, but was susceptible to amikacin, gentamicin, ciprofloxacin, levofloxacin, trimethoprim/sulfamethoxazole and piperacillin/tazobactam. The patient was treated successfully by debridement, cephapirin sodium and astromicine sulfate.
Wound Infection/*etiology ; Male ; Humans ; Gram-Negative Bacterial Infections/*etiology ; Chromobacterium/*isolation & purification ; Adult ; *Accidents, Traffic

Rapidly increasing antimicrobial resistance and lack of effective antibiotics are dilemma in the treatment of infectious diseases. Clinicians are now considering the use of old antibiotics such as colistin, fosfomycin because of limitation of therapeutic options. The unique pharmacokinetic and pharmacodynamics properties of these antibiotics have led the new therapeutic approaches, such as the combination of agents and newer dosing regimens. Colistin has become the last drug of the treatment of multidrug resistant gram-negative bacteria and the loading dose and high dose maintenance has been suggested. Tigecycline is licensed for the treatment of complicated skin and intra-abdominal infections and has broad activity against gram-positive and gram-negative pathogens but cautious use in the treatment of bloodstream infection and pneumonia is recommended. Oral and intravenous fosfomycin may be effective treatment options in the case of resistant gram-negative infections but clinical studies are limited.
Anti-Bacterial Agents ; Bacteria* ; Colistin ; Communicable Diseases ; Fosfomycin ; Gram-Negative Bacteria ; Intraabdominal Infections ; Pneumonia ; Skin

Achromobacter denitrificans ; Adult ; Gram-Negative Bacterial Infections ; complications ; Humans ; Jaundice, Obstructive ; etiology ; Liver Abscess ; microbiology ; Male

BACKGROUND: Infection is a frequent complication in patients with chronic liver disease, mainly during the advanced stages. This study was performed to investigate the risk factors for infections in hospitalized patients with decompensated liver cirrhosis. METHODS: We analyzed 108 decompensated hospitalized cirrhotic patients (34 cases with infection and 117 cases without infection) without clinical evidence of infection at the time of admission and during initial 72 hours after admission. RESULTS: Univariate and multivariate analysis revealed that patients who developed an infection were more likely to have a lower serum albumin levels. Gram-negative bacterial strains were detected most frequently, in 13 of the 18 strains isolated. There was no significant difference in etiology of disease, Child-Pugh classification, cirrhotic complications including upper G-I bleeding, hepatocelluar caricnoma, invasive procedure, diabetus mellitus, admission to ICU, duration of admission, survival rate and various parameters related to liver and renal function between patients with infection and without infection. CONCLUSION: The present study indicates that decompensated cirrhotic patient with low serum albumin levels have a higher risk of developing a hospital acquired infection, especially by gram negative bacteria.
Classification ; Cross Infection ; Gram-Negative Bacteria ; Gram-Negative Bacterial Infections ; Hemorrhage ; Humans ; Liver Cirrhosis* ; Liver Diseases ; Liver* ; Multivariate Analysis ; Risk Factors* ; Serum Albumin ; Survival Rate

OBJECTIVENanobacteria, a new kind of bacteria found by a Finnish scholar, is considered to relate to many human diseases like nephrolithiasis. However, there are no data available on nanobacteria infection in Chinese people.

METHODSNanobacteria was detected in serum of 336 cases of healthy adults in Southern China by enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry stain. The monoclonal antibody of nanobacterum was supplied by Kuipio University of Finland.

RESULTSNanobacteria infection rates were 27 (8.0%), 19 (5.7%) in the healthy adults by ELISA and immunohistochemistry stain respectively. No difference was shown between the 2 methods and between male and female, statistically. Age and sex did not seem to be related to the infectious risk of nanobacteria. However, the infectious rate was lower in those below 30-year-old than that of people over 60-year-old (P < 0.05).

CONCLUSIONNanobacteria was existed in the serum of Chinese healthy people with an infectious rate of 8.0%.

Adult ; Arteriosclerosis ; microbiology ; China ; epidemiology ; Enzyme-Linked Immunosorbent Assay ; Female ; Gram-Negative Bacteria ; isolation & purification ; Gram-Negative Bacterial Infections ; blood ; epidemiology ; microbiology ; Humans ; Immunohistochemistry ; Kidney Calculi ; microbiology ; Male

OBJECTIVEThis study aims to assess and compare the prevalence of Porphyromonas endodontalis (P. endodontalis) in root canals associated with primary and secondary endodontic infections by using 16s rDNA PCR and real-time fluorescence quantitative polymerase chain reaction (RTFQ-PCR).

METHODSA total of 120 adult patients with one radiographically documented periapical lesion were included. Sixty teeth presented with primary endodontic infections and 60 with secondary endodontic infections requiring retreatment. P. endodontalis was identified by using 16s rDNA PCR techniques. The positive DNA expression of P. endodontalis in two types of infected root canals were quantitatively compared by using SYBR GREEN I RTFQ-PCR.

RESULTSThe prevalence of P. endodontalis in the root canals with primary endodontic infections was significantly higher than that in root canals with secondary endodontic infections (P = 0.001). However, RTFQ-PCR results showed no significant difference in DNA expression quantities between the primary and secondary endodontic infections root canals (P = 0.303).

CONCLUSIONP. endodontalis is more highly associated with root canals having primary endodontic infections, although P. endodontalis colonize in both root canals with primary and secondary chronic apical periodontitis.

Adult ; DNA, Bacterial ; Dental Pulp Cavity ; Gram-Negative Bacterial Infections ; Humans ; Polymerase Chain Reaction ; Porphyromonas endodontalis ; Retreatment