Major pathogenic Gramnegative organisms such as P. aeruginosa, Serratia species, E. coli, Enterobacter species which are isolated from the specimens in large medical centers are greatly resistant to the commonly used antibiotics. Gramnegative bacilli, which had been isolated in Yeungnam Uni rersity Hospital during the period from December 1992 to April 1993 and turned out to be resistant to the primary antibiotics susceptibility test for chloramphenicoi, ampicillin, eephaiothin,- geniamicitt, tetracyclin, amikin and tobramycin, were subjected to the secondary antibiotics susceptibility test for aztreonam, ceftazidime, ciprofloxacine, cefotaxime, cefamandole, piperacillin, ticarcillin and sulfamethoxazole trimethopime. Out of 315 tested organisms, 167 organisms (53%) were resistant to all secondary antibiotics in vitro. Antimicrobial activity of ceftazidime (37.1%), aztreonam (11. %), ciprofloxacine (7.9%) against Gram negative bacilli were slightly more active than other antibiotics tested, while cefamandole was not active to all the Gramnegative bacilli tested. According to the specimens, E. coli was the most frequently resistant organisms to the primary antibiotics from urine, A. baumanii, from respiratory system and wounds, and P. aeruginosa from various specimens. In summary, Gram negative bacilli resistant to the primarily applied antibiotics also were resistant to the secondary antibiotics. Rearrangement of the antibiotics disks for the antibiotic susceptibility test should be considered.
Amikacin ; Ampicillin ; Anti-Bacterial Agents* ; Aztreonam ; Cefamandole ; Cefotaxime ; Ceftazidime ; Ciprofloxacin ; Enterobacter ; Piperacillin ; Respiratory System ; Serratia ; Sulfamethoxazole ; Ticarcillin ; Tobramycin ; Wounds and Injuries

BACKGROUND: We monitored the prevalence of antimicrobial resistance and the pattern of multiple drug resistance in Escherichia coli isolated from healthy people in the community. METHODS: We performed antimicrobial susceptibility testing on 491 isolates of E. coli from 692 healthy people in Incheon from February to July in 2006. The results were interpreted according to the CLSI guidelines. RESULTS: The highest rate of resistance was observed against tetracycline (46.6%), ampicillin (41.1%), ticarcillin (37.9%), streptomycin (31.0%), and nalidixic acid (23.6%). Twenty six percent of isolates were observed to be resistant to five or more of the antimicrobials tested. CONCLUSION: In order to maintain a low level of antimicrobial use and resistance, the surveillance of antimicrobial resistance in the community would be very important, as it provides epidemical data to set up and control antibiotic guidelines and serves as an early warning for resistance in pathogenic bacteria.
Ampicillin ; Bacteria ; Drug Resistance, Multiple ; Escherichia coli* ; Escherichia* ; Healthy Volunteers* ; Incheon ; Nalidixic Acid ; Prevalence ; Streptomycin ; Tetracycline ; Ticarcillin

Of total 1,438 specimens of patients with diarrhea in Seoul, 2011, 217 samples (15%) were found pathogenic Escherichia coli that included 192 strains (89%) of enterotoxigenic E. coli (ETEC) and enteroaggregative E. coli (EAEC). The highest isolation rate for ETEC and EAEC was found in August and September. Sixty two pathogenic E. coli strains (34 ETEC and 28 EAEC strains) were selected from 175 strains (94 ETEC and 81 EAEC strains) isolated in August and September. Of 94 strains characterized for ETEC phenotype, 76 (81%) expressed heat-stable toxin (ST) only. Antimicrobial susceptibility test was carried out by using sixteen types of antibiotics. A high level of antimicrobial resistance to tetracycline (57%), ampicillin and ticarcillin (54%) was observed among EAEC isolates while the highest resistance rate of ETEC was found for nalidixic acid (47%), followed by tetracycline (32%). As to the antimicrobial susceptibility test, EAEC showed the complicated multi-drug resistant patterns in which the resistance was higher than ETEC. Pulsed-field gel electrophoresis (PFGE) was carried out to examine the genetic relatedness among ETEC and EAEC isolates. Except for 11 strains, 51 strains were divided by eight pulsotypes. In PFGE analysis, isolates from foodborne disease outbreaks in August and September 2011 showed close relation.
Ampicillin ; Anti-Bacterial Agents ; Diarrhea ; Disease Outbreaks ; Electrophoresis, Gel, Pulsed-Field ; Enterotoxigenic Escherichia coli ; Escherichia coli ; Foodborne Diseases ; Humans ; Nalidixic Acid ; Phenotype ; Tetracycline ; Ticarcillin

Bifidobacterium longum, indigenous bacteria of the gastrointestinal tract, is a species of anaerobic non-spore-forming gram-positive bacilli, and appears to play an important role in preventing overgrowth of pathogenic bacteria. This organism is very rarely isolated from clinical specimens. It is known to be very difficult to identify Bifidobacterium longum due to not only the variability in aerotolerance, colony morphology and stainability on gram staining, resulting the failure of distinguishing from other anaerobic non-spore-forming gram-positive bacilli by the conventional biochemical tests. Definitive identification of genus Bifidobacterium requires the analysis of the end-products of metabolism, volatile and non-volatile fatty acids, by gas-liquid chromatography (GLC). We report a case of sepsis caused by Bifidobacterium longum in a 19-year-old male who developed high fever, jaundice and hepatomegaly after he had been introduced with many small gold needles. Anaerobic non-spore-forming gram-positive bacilli were isolated from his blood and identified as Bifidobacterium longum by performing biochemical tests and the analysis of the metabolic end-products by GLC. He has been completely recovered after ticarcillin and metronidazole therapy. To our knowledge, this is the first report of incidental sepsis by Bifidobacterium longum in the world.
Bacteria ; Bifidobacterium* ; Chromatography, Gas ; Fatty Acids ; Fever ; Gastrointestinal Tract ; Hepatomegaly ; Humans ; Jaundice ; Male ; Metabolism ; Metronidazole ; Needles ; Sepsis* ; Sulfalene* ; Ticarcillin ; Young Adult

BACKGROUND AND OBJECTIVES: In patients with fungal sinusitis, purulent discharge from the maxillary sinus is frequently observed and it responds to antibiotic treatment. Even though fungal sinusitis is resolved after surgery, the purulent discharge continues in some cases. We aimed to identify the pathogens of the purulent discharge in fungal sinusitis and to obtain information for appropriate antibiotics through a sensitivity test. MATERIALS AND METHOD: Among 71 patients with fungal sinusitis of the maxillary sinus, purulent secretions were found in 44 patients (62%) during an endoscopic sinus surgery. Endoscope-guided collection of the maxillary sinus secretions were performed and specimens were sent to the laboratory for bacterial cultures and antibiotic sensitivity tests. RESULTS: Among 44 cases with fungal lesions and purulent secretion in the maxillary sinus, bacteria were isolated in 27 cases (61.4%). Gram (+) aerobes were recovered in 19 cases, and Gram (-) aerobes were recovered in 16 cases. Mixed infection by Gram (+) and Gram (-) bacteria were observed in 8 patients. Anaerobic bacteria were not isolated. Among the Gram (+) aerobes, S. aureus was the most common organism (8 cases), while Enterobacter aerogenes was the most common organism (7 cases) of the Gram (-) aerobes. In an antibiotic sensitivity test for Gram (+) bacteria, ciprofloxacin, vancomycin, and teicoplanin showed sensitivity over 85 %. For Gram (-) bacteria, ceftazidime, ciprofloxacin, ticarcillin, tobramycin, and imipenem showed sensitivity over 90%. CONCLUSION: In patients with fungal sinusitis, concomitant bacterial infections are identified in more than half of the cases. Thus, postoperative administration of appropriate antibiotics can be justified in the treatment of fungal sinusitis.
Anti-Bacterial Agents* ; Bacteria* ; Bacteria, Anaerobic ; Bacterial Infections ; Bacteriology ; Ceftazidime ; Ciprofloxacin ; Coinfection ; Enterobacter aerogenes ; Humans ; Imipenem ; Maxillary Sinus* ; Maxillary Sinusitis* ; Sinusitis ; Teicoplanin ; Ticarcillin ; Tobramycin ; Vancomycin

Burkholderia pseudomallei is a gram-negative opportunistic intracellular pathogen that causes an acute and fatal septicemic melioidosis in humans. The organism is mainly found in Southeastern Asia and Northern Australia. Recently, we encountered a case of melioidosis in a Korean patient and performed the laboratory diagnosis of melioidosis. As a result, a gram negative bacterium was isolated from a melioidosis patient, and it was identified as B. pseudomallei on DNA sequencing of 16S ribosomal RNA with 99.9% homology and biochemical examination of VITEK gram-negative identification card. Also, DNA from cultured bacteria was tested in multiplex PCR, a 245 bp fragment amplified from the metalloprotease gene and a fragment of variable size ranging from 400~700 bp resulting from amplification of the 10 bp repetitive element for B. pseudomallei were confirmed after electrophoresis. The bacterium was sensitive to ceftazidime, imipenem and meropenem but resistant to ticarcillin. So far, there are no domestic cases of melioidosis in Korea, however, due to the increase in international travelers, the incidence of melioidosis is likely to increase. We report a recent case of melioidosis in a Korean patient.
Asia, Southeastern ; Australia ; Bacteria ; Burkholderia pseudomallei ; Ceftazidime ; Clinical Laboratory Techniques ; DNA ; Electrophoresis ; Humans ; Imipenem ; Incidence ; Korea ; Melioidosis ; Multiplex Polymerase Chain Reaction ; RNA, Ribosomal, 16S ; Sequence Analysis, DNA ; Thienamycins ; Ticarcillin

Shiga toxin-producing Escherichia coli (STEC) strains are commensal bacteria in cattle and cause food borne disease in human. We analyzed the isolation rate of STEC in stool specimens of patients with diarrhea and in fecal samples of cattle in Gwangju, Korea. STEC strains were detected from 33 (0.19%) out of 17,148 patients with diarrhea while there has been a progressive increase in the incidence rate from 0.07% in 2004 to 0.33% in 2008. We investigated serotypes, shiga toxin genes, and antimicrobial resistance patterns of the 44 STEC isolates from human and cattle sources. The 33 STEC isolates from human belonged to 14 O serotypes including O157, O26 and O111. The 11 isolates from cattle belonged to 11 O serotypes. PCR detection for stx genes showed that 12 (27.3%) isolates carried stx1 genes, 20 (45.5%) possessed stx2 genes, and 12 (27.3%) carried both stx1 and stx2. Of the 33 STEC isolates from human, 25 strains (76%) were resistant to one or more antibiotics. High level of resistance to tetracycline (73%) was most common, followed by ticarcillin and ampicillin (64%). But none of the 33 isolates from human were resistant to amikacin, cefazolin, cefepime, cefotetan, cefotaxime, ciprofloxacin, or imipenem. The 5 strains (45%) of the 11 isolates from cattle were resistant to at least one or three antibiotics but most of the isolates were sensitive to the 16 antibiotics employed in this survey. In conclusion, toxin types and serotypes of STEC isolated from human and cattle were diverse, and non-O157 STEC was also observed to be a greater proportion of STEC isolates. According to a specific comparison solely based on the toxin types and serotypes, most of the STEC strains isolated from cattle feces in Gwangju, Korea showed characteristics different from those isolated from patients. Therefore, laboratory surveillance is required to detect and carefully monitor the potentially hypervirulent STEC not only in human and cattle but also in other animals.
Amikacin ; Ampicillin ; Animals ; Anti-Bacterial Agents ; Bacteria ; Cattle ; Cefazolin ; Cefotaxime ; Cefotetan ; Cephalosporins ; Ciprofloxacin ; Diarrhea ; Feces ; Humans ; Imipenem ; Incidence ; Korea ; Organothiophosphorus Compounds ; Polymerase Chain Reaction ; Shiga Toxin ; Shiga-Toxigenic Escherichia coli ; Tetracycline ; Ticarcillin

BACKGROUND: Acinetobacter baumannii has emerged as a major cause of nosocomial outbreaks. It is particularly associated with nosocomial pneumonia and bloodstream infections in immunocompromised and debilitated patients with serious underlying pathologies. Over the last two decades, a remarkable rise in the rates of multidrug resistance to most antimicrobial agents that are active against A. baumannii has been noted worldwide. We evaluated the rates of antimicrobial resistance and changes in resistance over a 5-year period (2010–2014) in A. baumannii strains isolated from hospitalized patients in a tertiary Greek hospital. MATERIALS AND METHODS: Identification of A. baumannii was performed by standard biochemical methods and the Vitek 2 automated system, which was also used for susceptibility testing against 18 antibiotics: ampicillin/sulbactam, ticarcillin, ticarcillin/clavulanic acid, piperacillin, piperacillin/tazobactam, cefotaxime, ceftazidime, cefepime, imipenem, meropenem, gentamicin, amikacin, tobramycin, ciprofloxacin, tetracycline, tigecycline, trimethoprim/sulfamethoxazole, and colistin. Interpretation of susceptibility results was based on the Clinical and Laboratory Standards Institute criteria, except for tigecycline, for which the Food and Drug Administration breakpoints were applied. Multidrug resistance was defined as resistance to ≥3 classes of antimicrobial agents. RESULTS: Overall 914 clinical isolates of A. baumannii were recovered from the intensive care unit (ICU) (n = 493), and medical (n = 252) and surgical (n = 169) wards. Only 4.9% of these isolates were fully susceptible to the antimicrobials tested, while 92.89% of them were multidrug resistant (MDR), i.e., resistant to ≥3 classes of antibiotics. ICU isolates were the most resistant followed by isolates from surgical and medical wards. The most effective antimicrobial agents were, in descending order: colistin, amikacin, trimethoprim/sulfamethoxazole, tigecycline, and tobramycin. Nevertheless, with the exception of colistin, no antibiotic was associated with a susceptibility rate >40% for the entire study period. The most common phenotype showed resistance against ampicillin/sulbactam, cephalosporins, carbapenems, aminoglycosides, ciprofloxacin, and tigecycline. An extremely concerning increase in colistin-resistant isolates (7.9%) was noted in 2014, the most recent study year. CONCLUSION: The vast majority of A. baumannii clinical isolates in our hospital are MDR. The remaining therapeutic options for critically ill patients who suffer from MDR A. baumannii infections are severely limited, with A. baumannii beginning to develop resistance even against colistin. Scrupulous application of infection control practices should be implemented in every hospital unit. Lastly, given the lack of available therapeutic options for MDR A. baumannii infections, well-controlled clinical trials of combinations of existing antibiotics are clearly needed.
Acinetobacter baumannii* ; Acinetobacter* ; Amikacin ; Aminoglycosides ; Anti-Bacterial Agents ; Anti-Infective Agents ; Carbapenems ; Cefotaxime ; Ceftazidime ; Cephalosporins ; Ciprofloxacin ; Colistin ; Critical Illness ; Disease Outbreaks ; Drug Resistance, Multiple ; Gentamicins ; Hospital Units ; Humans ; Imipenem ; Infection Control ; Intensive Care Units ; Pathology ; Phenotype ; Piperacillin ; Pneumonia ; Tetracycline ; Ticarcillin ; Tobramycin ; United States Food and Drug Administration