BACKGROUND: Mecillinam, an amidinopenicillin antibiotic, has been used to treat urinary tract infections and bacterial enteritis in many countries. In this study, we evaluated in vitro activity of mecillinam against Enterobacteriaceae isolates from urine, and Salmonella and Shigella isolates from patients with bacterial gastroenteritis. MATERIALS AND METHODS: A total of 308 clinical strains were collected and were comprised of Escherichia coli (n=109), Klebsiella pneumoniae (n=52), Enterobacter spp. (n=30), Serratia marcescens (n=30) and Proteus spp. (n=29) isolated from a university hospital in Korea in 2007, and of Salmonella spp. (n=28) and Shigella spp. (n=30) isolated from Korean diarrheal patients from 2001 to 2006. Antimicrobial susceptibility was tested by Clinical Laboratory Standard Institute (CLSI) agar dilution method. CLSI breakpoint of mecillinam for E. coli urinary tract isolates was applied to all other isolates. RESULTS: In E. coli, rate of susceptibility to ampicillin was 30%, but 99-100% to amikacin and cefotaxime. Most (96%) of E. coli isolates, including extended-spectrum beta-lactamase (ESBL) producers, were susceptible to mecillinam. All ESBL producers, except for one isolate, were inhibited by < or =4 microg/mL of mecillinam. MIC90 of mecillinam for K. pneumoniae and Enterobacter spp. was 8 microg/mL and 1 microg/mL, respectively, and the susceptibility rate was 92% and 97%, respectively. However, MIC90 of mecillinam for S. marcescens isolates was >128 microg/mL and most of them were resistant to mecillinam. All Salmonella isolates and 27 of 30 Shigella isolates were susceptible to mecillinam. CONCLUSION: Mecillinam was active in vitro against most Enterobacteriaceae, Salmonella, and Shigella isolates except for S. marcescens. Therefore, mecillinam can be a good alternative agent for treating urinary tract infection and bacterial gastroenteritis.
Agar ; Amdinocillin ; Amikacin ; Ampicillin ; beta-Lactamases ; Cefotaxime ; Enteritis ; Enterobacter ; Enterobacteriaceae ; Escherichia coli ; Gastroenteritis ; Humans ; Klebsiella pneumoniae ; Korea ; Pneumonia ; Proteus ; Salmonella ; Serratia marcescens ; Shigella ; Urinary Tract ; Urinary Tract Infections

BACKGROUND: Mecillinam, an amidinopenicillin antibiotic, has been used to treat urinary tract infections and bacterial enteritis in many countries. In this study, we evaluated in vitro activity of mecillinam against Enterobacteriaceae isolates from urine, and Salmonella and Shigella isolates from patients with bacterial gastroenteritis. MATERIALS AND METHODS: A total of 308 clinical strains were collected and were comprised of Escherichia coli (n=109), Klebsiella pneumoniae (n=52), Enterobacter spp. (n=30), Serratia marcescens (n=30) and Proteus spp. (n=29) isolated from a university hospital in Korea in 2007, and of Salmonella spp. (n=28) and Shigella spp. (n=30) isolated from Korean diarrheal patients from 2001 to 2006. Antimicrobial susceptibility was tested by Clinical Laboratory Standard Institute (CLSI) agar dilution method. CLSI breakpoint of mecillinam for E. coli urinary tract isolates was applied to all other isolates. RESULTS: In E. coli, rate of susceptibility to ampicillin was 30%, but 99-100% to amikacin and cefotaxime. Most (96%) of E. coli isolates, including extended-spectrum beta-lactamase (ESBL) producers, were susceptible to mecillinam. All ESBL producers, except for one isolate, were inhibited by < or =4 microg/mL of mecillinam. MIC90 of mecillinam for K. pneumoniae and Enterobacter spp. was 8 microg/mL and 1 microg/mL, respectively, and the susceptibility rate was 92% and 97%, respectively. However, MIC90 of mecillinam for S. marcescens isolates was >128 microg/mL and most of them were resistant to mecillinam. All Salmonella isolates and 27 of 30 Shigella isolates were susceptible to mecillinam. CONCLUSION: Mecillinam was active in vitro against most Enterobacteriaceae, Salmonella, and Shigella isolates except for S. marcescens. Therefore, mecillinam can be a good alternative agent for treating urinary tract infection and bacterial gastroenteritis.
Agar ; Amdinocillin ; Amikacin ; Ampicillin ; beta-Lactamases ; Cefotaxime ; Enteritis ; Enterobacter ; Enterobacteriaceae ; Escherichia coli ; Gastroenteritis ; Humans ; Klebsiella pneumoniae ; Korea ; Pneumonia ; Proteus ; Salmonella ; Serratia marcescens ; Shigella ; Urinary Tract ; Urinary Tract Infections

This study was performed for the assessing the distribution, drug resistance and its transferability, and cell agglutinating ability of Enterobacteriaceae isolated from urine of patients with urinary tract infection. Total 164 strains of Strains of Enterobacteriaceae including, 91 strains of E. coli, 35 strains of klebsiella, 23 strains of Proteus, 6 strains of Serratia, 6 strains of Citrobacter, 3 strains of Enterobacteriaceae were isolated from urine. In the cell agglutinating test, most organisms, except Proteus, showed mannose resistant agglutination. Among organisms tested more than 20 strains, E. coli showed highest frequency of cell agglutination. In the comparison of cell agglutinating characteristics of E. coli and Klebsiella isolated from urine and other sources urinary isolates of E. coli showed higher frequency of agglutination and greater agglutinating potency than isolates from other sources, but Klebsiella showed little difference between isolates of urine and other sources. Urinary isolates usually showed high frequency of resistance to penicillin(90%), ampicillin(89%). sulfamethoxazole(69%), tetracycline(66%), chloramphenicol(53%), but showed low frequency of resistance to moxalactam(1%), amikacin(2%), and nalidixic acid (9%), and these resistance were highly transferable resistance mediated by R plasmid.
Agglutination ; Citrobacter ; Drug Resistance* ; Enterobacteriaceae ; Humans ; Klebsiella ; Mannose ; Nalidixic Acid ; Plasmids ; Proteus ; Serratia ; Urinary Tract Infections

We investigated the occurrence and genetic basis of AmpC beta-lactamase (AmpC)-mediated antibiotic resistance, by examining Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis isolates at a university hospital, from 2007 to 2010. The ampC genes were detected by multiplex AmpC PCR, and AmpC-positive strains were subjected to DNA sequencing. Extended-spectrum beta-lactamase (ESBL) production was assessed using the ESBL disk test based on the utilization of boronic acid. Carbapenem-resistant isolates were further investigated by the modified Hodge test, a carbapenemase inhibition test and SDS-PAGE experiments. AmpC expression was detected in 1.6% of E. coli (39 DHA-1, 45 CMY-2, and 1 CMY-1) isolates, 7.2% of K. pneumoniae (39 DHA-1, 45 CMY-2, and 1 CMY-1) isolates, and 2.5% of P. mirabilis (8 CMY-2 and 1 CMY-1) isolates. Of the 198 acquired AmpC producers, 58 isolates (29.3%) also produced an ESBL enzyme. Among the acquired AmpC-producing K. pneumoniae isolates, the minimum inhibitory concentration (MIC) MIC50/MIC90 values for cefoxitin, cefotaxime, cefepime, imipenem, and meropenem were >32/>32, 16/>32, 1/16, 0.25/0.5, and <0.125/0.125 microg/mL, respectively. The MIC values for carbapenem were > or =2 microg/mL for 2 K. pneumoniae isolates, both of which carried the blaDHA-1 gene with a loss of OmpK36 expression, but were negative for carbapenemase production. The acquisition of AmpC-mediated resistance in K. pneumoniae isolates increased, as did the proportion of AmpC and ESBL co-producers among the hospital isolates. The accurate identification of isolates producing AmpCs and ESBLs may aid in infection control and will assist physicians in selecting an appropriate antibiotic regimen.
Anti-Bacterial Agents/pharmacology ; Bacterial Proteins/*genetics ; DNA, Bacterial/genetics ; Enterobacteriaceae Infections/*epidemiology/*microbiology ; Escherichia coli/drug effects/enzymology/isolation & purification ; Hospitals, University/statistics & numerical data ; Humans ; Klebsiella pneumoniae/drug effects/enzymology/isolation & purification/*physiology ; Microbial Sensitivity Tests ; Multiplex Polymerase Chain Reaction ; Proteus mirabilis/drug effects/enzymology/isolation & purification ; Republic of Korea/epidemiology ; beta-Lactamases/*genetics

BACKGROUND: The purpose of this study was to compare the outcome of carbapenem versus non-carbapenem antimicrobial therapy for pediatric urinary tract infections (UTIs) caused by extended-spectrum beta-lactamase (ESBL) producing Enterobacteriaceae. MATERIALS AND METHODS: From 2006 to 2011, 42 episodes of UTI caused by ESBL-producing Enterobacteriaceae were diagnosed at Seoul National University Children's Hospital. Patients were grouped according to the antimicrobials they received into a carbapenem group and a non-carbapenem group. Medical records were retrospectively reviewed to assess treatment outcome, time to defervescence after initiation of treatment, and relapse rate. RESULTS: There were 36 children with 42 episodes of UTI caused by ESBL-producing Enterobacteriaceae. Twenty-seven cases (64%) had an underlying urologic disease, 28 (67%) cases were caused by Escherichia coli, and 14 (33%) cases were caused by Klebsiella pneumoniae. Four (10%) cases were treated with carbapenem, 23 cases (55%) were treated with non-carbapenem, and 15 (36%) cases were treated by switching from a carbapenem to a non-carbapenem and vice versa. There was no treatment failure at the time of antimicrobial discontinuation. Between the carbapenem and the non-carbapenem treatment groups, there were no significant differences in bacterial etiology (P = 0.59), time to defervescence after the initiation of antimicrobials (P = 0.28), and relapse rate (P = 0.50). In vitro susceptibility to non-carbapenem antimicrobials did not affect the time to defervescence after the initiation of antimicrobial treatment, and the relapse rate in the non-carbapenem group. CONCLUSIONS: This study found no significant difference in the treatment outcome between pediatric patients treated with carbapenem and those treated with non-carbapenem antimicrobials for UTI caused by ESBL-producing Enterobacteriaceae. Therefore, the initially administered non-carbapenem can be maintained in UTI patients showing clinical improvement.
beta-Lactamases ; Child ; Enterobacteriaceae* ; Escherichia coli ; Humans ; Klebsiella pneumoniae ; Medical Records ; Recurrence ; Retrospective Studies ; Seoul ; Treatment Failure ; Treatment Outcome ; Urinary Tract Infections* ; Urinary Tract* ; Urologic Diseases

The purpose of the study was to collect the opinions of doctors who are specialists in infectious disease with regard to the current method used for isolation of patients with group 1 nationally notifiable infectious diseases in Korea. A web-based survey was conducted from June 27 to July 7, 2011. Relevant questions included: 1) adequacy of the current policy of forced hospital isolation; evaluation of current guidelines for release from hospital isolation; and 3) priority for policy switching from forced hospital isolation to home isolation. The rate of response to the survey was 28.4% (40 out of 140). First, the majority of infectious disease specialists in Korea believed that the current method of forced hospital isolation for patients with group 1 infectious diseases should be changed to the home isolation method. Second, if the Korean government changes its policy to home isolation, the top priority of the policy switch would be typhoid fever, followed by paratyphoid fever, shigellosis, cholera, and EHEC (enterohemorigic Escherichia coli). Regarding current guidelines for release from hospital isolation, in cases of shigellosis, EHEC, and hepatitis A, the majority of respondents supported the current guidelines, while they were not able to make collective opinions in cases of cholera and typhoid/paratyphoid fever. We were able to confirm that the majority of specialists want to change the current isolation method. Therefore, the Korean government should consider switching their policy from forced hospital isolation to home isolation.
Cholera ; Communicable Diseases ; Dysentery, Bacillary ; Enterohemorrhagic Escherichia coli ; Escherichia ; Fever ; Hepatitis A ; Humans ; Infectious Disease Medicine ; Korea ; Paratyphoid Fever ; Specialization ; Surveys and Questionnaires ; Typhoid Fever

BACKGROUND: Resistant organisms are now a growing and frequent problem in community-acquired infections. There is little information on the etiology and antimicrobial susceptibility patterns of community-acquired urinary tract infection (CA-UTI) at a tertiary-care hospital. METHODS: We evaluated the distribution of etiological organisms with their antimicrobial susceptibility patterns of CA-UTI in the patients visiting a tertiary-care hospital during the period of three years from 2001 through 2003. RESULTS: In total, 1,753 bacterial isolates yielded a significant growth as pathogens of CA-UTI in this study. The most common pathogen was Escherichia coli (38.3%), followed by Pseudomonas aeruginosa (10.8%), Enterococcus faecalis (7.3%), Klebsiella pneumoniae (6.4%), coagulase negative staphylococci (CoNS) (5.4%) and Staphylococcus aureus (5.2%). The prevalence of E. coli was significantly higher in females (P < 0.001), whereas P. aeruginosa, E. faecalis, and S. aureus were significantly more common in male group (P < 0.001). The susceptibility rate of E. coli was 26.0% to ampicillin, 65.8% to gentamicin, 51.3% to co-trimoxazole, and 62.5% to ciprofloxacin. The susceptibility patterns of Enterobacteriaceae other than E. coli were different from those of E. coli. Extended spectrum beta-lactamase was detected in 7.9% of E. coli and 15.6% of K. pneumoniae. CONCLUSION: This study demonstrates a diversity of etiological organisms and a high rate of resistance to commonly used antimicrobials of CA-UTI in patients visiting a tertiary-care hospital.
Ampicillin ; beta-Lactamases ; Ciprofloxacin ; Coagulase ; Community-Acquired Infections ; Drug Resistance, Microbial ; Enterobacteriaceae ; Enterococcus faecalis ; Escherichia coli ; Female ; Gentamicins ; Humans ; Klebsiella pneumoniae ; Male ; Pneumonia ; Prevalence ; Pseudomonas aeruginosa ; Staphylococcus aureus ; Trimethoprim, Sulfamethoxazole Drug Combination ; Urinary Tract Infections* ; Urinary Tract*

PURPOSE: This study was performed to evaluate the compliance with, and adequacy of, the Korean national guidelines which had been recommended until 2011 for isolation of patients with group 1 nationally notifiable infectious diseases (NNIDs), namely cholera, typhoid fever, paratyphoid fever, shigellosis, and enterohemorrhagic Escherichia coli (EHEC) infection. MATERIALS AND METHODS: We evaluated the clinical and microbiological characteristics of confirmed cases of group 1 NNIDs and compliance with the guidelines in 20 Korean hospitals nationwide in 2000-2010. We also compared the Korean guidelines with international guidelines. RESULTS: Among 528 confirmed cases (8 cases of cholera, 232 of typhoid fever, 81 of paratyphoid fever, 175 of shigellosis, and 32 EHEC infections), strict compliance with the Korean guideline was achieved in only 2.6% to 50.0%, depending on the disease. While the Korean guidelines recommend isolation of all patients with group 1 NNIDs, international guidelines recommend selective patient isolation and screening for fecal shedding, depending on the type of disease and patient status. CONCLUSION: Compliance with the previous national guidelines for group 1 NNIDs in Korea was generally very low. Further studies are needed to evaluate whether compliance was improved after implementation of the new guideline in 2012.
Cholera ; Communicable Disease Control ; Communicable Diseases* ; Compliance* ; Dysentery, Bacillary ; Enterohemorrhagic Escherichia coli ; Guideline Adherence ; Humans ; Korea* ; Mass Screening ; Methods ; Paratyphoid Fever ; Patient Isolation ; Typhoid Fever

BACKGROUND: Extended-spectrum ß-lactamase-producing Enterobacteriaceae (ESBL-PE) are increasingly reported as pathogens in urinary tract infections (UTIs). However, in Sri Lanka, the clinical and molecular epidemiology of ESBL-PE implicated in UTIs has not been well described. MATERIALS AND METHODS: We conducted prospective, laboratory-based surveillance from October to December 2013 at a tertiary care hospital in southern Sri Lanka and enrolled patients ≥1 year of age with clinically relevant UTIs due to ESBL-PE. Isolate identity, antimicrobial drug susceptibility, and ESBL production were determined. Presence of ß-lactamase genes, bla(SHV), bla(TEM), and bla(CTX-M), was identified by polymerase chain reaction. RESULTS: During the study period, Enterobacteriaceae were detected in 184 urine samples, with 74 (40.2%) being ESBL producers. Among 47 patients with ESBL-PE who had medical records available, 38 (80.9%) had clinically significant UTIs. Most UTIs (63.2%) were community acquired and 34.2% were in patients with diabetes. Among 36 cultured ESBL-PE isolates, significant susceptibility (>80%) was only retained to amikacin and the carbapenems. The group 1 bla(CTX-M) gene was present in 90.0% of Escherichia coli isolates and all Klebsiella pneumoniae and Enterobacter cloacae isolates. The bla(SHV) and bla(TEM) genes were more common in K. pneumoniae (75% and 50%) and E. cloacae (50% and 50%) isolates than in E. coli (10% and 20%) isolates, respectively. CONCLUSION: The majority of UTIs caused by ESBL-PE were acquired in the community and due to organisms carrying the group 1 CTX-M ß-lactamase. Further epidemiologic studies of infections due to ESBL-PE are urgently needed to better prevent and treat these infections in South Asia.
Amikacin ; Asia ; Carbapenems ; Cloaca ; Enterobacter cloacae ; Enterobacteriaceae* ; Epidemiologic Studies ; Escherichia coli ; Humans ; Klebsiella pneumoniae ; Medical Records ; Molecular Epidemiology ; Pneumonia ; Polymerase Chain Reaction ; Prospective Studies ; Sri Lanka* ; Tertiary Healthcare ; Urinary Tract Infections* ; Urinary Tract*

PURPOSE: A catheter-associated urinary tract infection, which frequently occurs in patients with an indwelling Foley catheter, can cause serious morbidity or mortality. Recently, antibiotic coated Foley catheters, to prevent catheter-associated urinary tract infections, have become commercially available. This study investigated the long-term effects of the use of antibiotic-coated Foley catheters on biofilm formations. MATERIALS AND METHODS: Silicone Foley or antibiotic-coated Foley catheters were indwelled in 72 patients with a neurogenic bladder. Each catheter was removed 1, 3, 5, 7, 14 and 28 days after insertion. The cell densities of the biofilm bacteria were evaluated by counting the number of colonies on plate cultures. The biofilm formations on the catheters were evaluated by scanning electron microscopy. The inner surface morphology of the catheter was imaged by field emission scanning electron microscopy (Philips-XL20SFEG), at 10kV, following gold sputtering for electrical conductance. Six catheters were studied in each group, and the means calculated for comparisons. RESULTS: Thick bacterial biofilms were observed on both the antibiotic- coated and silicone Foley catheters 7 days after insertion. There were no significant differences in the cell densities of the biofilm bacteria between the two types of catheter during days 7-28 after insertion (p<0.05). Two to three species of bacteria were isolated from the catheters in each patient; the most common species were Pseudomonas, Klebsiella, Serratia, Proteus species and Escherichia coli. CONCLUSIONS: The antibiotic-coated Foley catheters showed no preventive effects on the biofilm formations after 7 days of indwelling compared with the silicone Foley catheters. Our data suggest that the routine use of antibiotic-coated Foley catheters to prevent catheter-associated infection in patients with a neurogenic bladder is not reasonable. The emergence of resistance associated with antibiotic-coated catheters should be evaluated.
Anti-Bacterial Agents ; Bacteria ; Biofilms* ; Catheter-Related Infections ; Catheters* ; Cell Count ; Escherichia coli ; Humans ; Klebsiella ; Microscopy, Electron, Scanning ; Mortality ; Proteus ; Pseudomonas ; Serratia ; Silicones ; Urinary Bladder, Neurogenic ; Urinary Tract Infections