1.Comparison of Epsilometer test and agar dilution method in detecting the sensitivity of Helicobacter pylori to metronidazole.
Xue Li TIAN ; Zhi Qiang SONG ; Bao Jun SUO ; Li Ya ZHOU ; Cai Ling LI ; Yu Xin ZHANG
Journal of Peking University(Health Sciences) 2023;55(5):934-938
OBJECTIVE:
Agar dilution method (ADM) was used as the golden standard to evaluate the consistency of Epsilometer test (E-test) in detecting the sensitivity of Helicobacter pylori (H. pylori) to metronidazole.
METHODS:
From August 2018 to July 2020, patients with H. pylori infection treated for the first time in Peking University Third Hospital for gastroscopy due to dyspepsia were included in this study. Gastric mucosas were taken from the patients with H. pylori infection. H. pylori culture was performed. Both the ADM and E-test were applied to the antibiotic susceptibility of H. pylori to metro-nidazole, and the consistency and correlation between the two methods were validated.
RESULTS:
In the study, 105 clinical isolates of H. pylori were successfully cultured, and the minimum inhibitory concentration ≥ 8 mg/L was defined as drug resistance. Both ADM and the E-test showed high resistance rates to metronidazole, 64.8% and 62.9%, respectively. Among them, 66 drug-resistant strains were detected by ADM and E-test, and 37 were sensitive strains, so the consistency rate was 98.1%. Two strains were evaluated as drug resistance by ADM, but sensitive by the E-test, with a very major error rate of 1.9%. There was zero strain sensitive according to ADM but assessed as resistant by the E-test, so the major error rate was 0%. Taking ADM as the gold standard, the sensitivity of E-test in the detection of metronidazole susceptibility was 97.1% (95%CI: 0.888-0.995), and the specificity was 100% (95%CI: 0.883-1.000). Cohen's kappa analysis showed substantial agreement, and kappa coefficient was 0.959 (95%CI: 0.902-1.016, P < 0.001). Spearmans correlation analysis confirmed this correlation was significant (r=0.807, P < 0.001). The consistency evaluation of Bland-Altman method indicated that it was good, and there was no measured value outside the consistency interval. In this study, cost analysis, including materials and labor, showed a 32.2% higher cost per analyte for ADM as compared with the E-test (356.6 yuan vs. 269.8 yuan).
CONCLUSION
The susceptibility test of H. pylori to metronidazole by E-test presents better agreement with ADM. Because it is less expensive, less labor intensive, and more rapid, it is an easy and reliable method for H. pylori susceptibility testing.
Humans
;
Metronidazole/therapeutic use*
;
Helicobacter pylori
;
Agar/therapeutic use*
;
Disk Diffusion Antimicrobial Tests
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Microbial Sensitivity Tests
;
Helicobacter Infections/drug therapy*
;
Anti-Bacterial Agents/therapeutic use*
2.Isolation, identification and antibiogram profiling of bacteria isolated from water, seafood, and macroplastic samples from Baseco Beach, Manila Bay
Marilen P. Balolong ; Edison Jay A. Pagoso ; Antonio Nikolai E. Tesoro ; Maria Constancia O. Carrillo ; Kei Kitahara
Philippine Journal of Health Research and Development 2020;24(3):20-30
Background and Objective:
Manila Bay plays an important role both in economics and ecology because it serves as the major economic center of the Philippines and as it harbors different habitats and biodiversity. Unfortunately, it is threatened by various pollutions including the unregulated discharge of wastewater from industrial, agricultural, and household sectors and improper disposal of trash such as macroplastics among others. All these contributes to the current state of Manila Bay. This study identified bacteria isolated from water, seafood and floating macroplastic samples from Baseco Beach, Manila Bay and determined their antibiogram profiles.
Methodology:
Bacterial isolates were obtained from water, seafoods and macroplastic samples from Baseco Beach, Manila Bay using conventional culture techniques. Identification of the isolates was done using Vitek-2 Automated System and antibiogram profiling was done using Kirby-Bauer Disk Diffusion Susceptibility Test.
Results and Conclusions
A total of 30 bacterial isolates were obtained from different samples from water, seafood and macroplastic samples from Baseco Beach, Manila Bay. These isolates were identified and found to belong to 13 different bacterial species with Bacillus spp. comprising 33.33% of the isolates (10 out of 30), and Vibrio alginolyticus comprising 23.33% of the isolates (7 out of 30) and the other species comprise the remaining 43.34% (Pseudomonas spp., Vibrio fluvialis, Klebsiella pneumoniae, Shewanella alga, Sphingomonas paucimobilis, Staphylococcus haemolyticus, Chryseobacterium indologenes, Myroides sp. and Aeromonas salmonicida). Of these, six out of 30 isolates (20%) showed susceptibility to all six representative antibiotics used (Cefazolin 30μg, Gentamicin 10 μg, Chloramphenicol 30 μg, ampicillin 10 μg, Cefuroxime 30 μg, Ceftazidime 30 μg) while 7 isolates (23.33%) were resistant to only one class of antibiotic. Moreover, 17 out of 30 isolates (56.66%) were resistant to two or more classes of antibiotic while only one isolate (3.33%) was found to be resistant to gentamicin. All 30 isolates (100%) were susceptible to chloramphenicol.
Interestingly, three antibiotic resistant (AMR) bacteria were isolated from macroplastics namely
Pseudomonas oleovorans (S2), Vibrio alginolyticus (S5), and Pseudomonas alcaligenes (S29) which were all resistant to ampicillin and cefazolin. This is the first study in the Philippines to isolate AMR bacteria from macroplastics from Manila Bay. The presence of AMR bacteria in macroplastics shows that these materials can be a reservoir for its dynamics and distribution. Lastly, with the emergence of antimicrobial resistant bacteria, the elucidation of the antibiogram profile of bacteria is necessary to determine its implication sand threats to public health. This study served as a baseline study of presence of AMR bacteria in macroplastic samples from Manila Bay.
ays
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Microbial Sensitivity Tests
;
Disk Diffusion Antimicrobial Tests
3.Antifungal susceptibility and virulence of Aspergillus fumigatus environmental strains from a public tertiary hospital in Metro Manila, Philippines
Ferissa B ABLOLA ; Alice alma C BUNGAY
Philippine Journal of Health Research and Development 2019;23(3):10-21
Background and Objectives: The increase in the number of invasive Aspergillus infections has been observed among immunocompromised and hospitalized patients. In the Philippines to date, no published data focused on the prevalence of Aspergillus species or any other thermotolerant fungal species in a hospital environment. This research served as a primary study to characterize the antifungal susceptibility of environmental strains of Aspergillus fumigatus from a hospital facility against three antifungal agents and to determine the virulence of these isolates on BALB/c mice using an animal survival assay.
Methodology: Ten environmental strains of A. fumigatus were isolated from three air-conditioned wards in a medical facility using Andersen Air Sampler. The antifungal susceptibility profile of the isolates was determined against Voriconazole, Amphotericin B and Caspofungin. The virulence of these isolates was also tested on BALB/c mice using an animal survival assay. Moreover, the lung tissues of infected BALB/c mice were subjected to histopathological analyses using Gomori Methenamine Silver stain (GMS) and Hematoxylin & Eosin (H&E) stains.
Results: Etest result for antifungal susceptibility testing showed that two of the ten isolates were resistant to Amphotericin B (AF2-A and AF-3A); one isolate resistant to Voriconazole (AF2-A) and an isolate that manifested non- susceptibility to Caspofungin m(AF2-A). Epidemiological cut-off values were determined for each antifungal following the M38-A2 CLSI guidelines. BALB/c mice median survival analysis revealed that the isolate with the highest Minimum Inhibitory Concentration (MIC= 4.89 ?g/ml) for Voriconazole resulted in the most number of mortality with the least number of observation days. GMS AND H&E histopathology slides showed fungal elements embedded on left lung lobe of mice.
Conclusion: This study showed that there were strains of Aspergillus fumigatus from a hospital indoor air which were considered as resistant strains to Voriconazole, Amphotericin B, and Caspofungin (AF2-A and AF3-A). Lung tissues of infected mice showed characteristics of bronchopneumonia.
Survival Analysis ; Disk Diffusion Antimicrobial Tests
4.Septicemia Caused by Neisseria meningitidis With Decreased Ciprofloxacin Susceptibility: The First Case Report in Korea.
Ji Yeon AHN ; Joon Ki MIN ; Myeong Hee KIM ; Soo Youn MOON ; Ki Ho PARK ; Mi Suk LEE ; Jun Seong SON
Annals of Laboratory Medicine 2016;36(3):275-277
No abstract available.
Anti-Bacterial Agents/pharmacology
;
Bacterial Proteins/genetics
;
Ceftriaxone/pharmacology/therapeutic use
;
Ciprofloxacin/pharmacology/therapeutic use
;
DNA, Bacterial/analysis/metabolism
;
Disk Diffusion Antimicrobial Tests
;
*Drug Resistance, Bacterial
;
Female
;
Humans
;
Neisseria meningitidis/drug effects/genetics/*isolation & purification
;
Polymerase Chain Reaction
;
Sepsis/*diagnosis/drug therapy/microbiology
;
Transcription Factors/genetics
;
Young Adult
5.Identification of Pasteurella canis in a Soft Tissue Infection Caused by a Dog Bite: The First Report in Korea.
Bongyoung KIM ; Hyunjoo PAI ; Kwang hyun LEE ; Yangsoon LEE
Annals of Laboratory Medicine 2016;36(6):617-619
No abstract available.
Animals
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Anti-Bacterial Agents/pharmacology
;
Bites and Stings
;
Disk Diffusion Antimicrobial Tests
;
Dogs
;
Female
;
Humans
;
Middle Aged
;
Pasteurella/drug effects/genetics/*isolation & purification
;
Pasteurella Infections/*diagnosis/microbiology
;
RNA, Ribosomal, 16S/chemistry/genetics/metabolism
;
Republic of Korea
;
Sequence Analysis, DNA
;
Soft Tissue Infections/*diagnosis/microbiology
6.Further Modification of the Modified Hodge Test for Detecting Metallo-beta-Lactamase-Producing Carbapenem-Resistant Enterobacteriaceae.
Hyun Ki KIM ; Jeong Su PARK ; Heungsup SUNG ; Mi Na KIM
Annals of Laboratory Medicine 2015;35(3):298-305
BACKGROUND: The modified Hodge test (MHT) was designed to detect carbapenemase-producing Enterobacteriaceae (CPE). This study evaluated variables to improve the performance of MHT. METHODS: Carbapenem-resistant Enterobacteriaceae isolated from November 2010 to March 2013 at the Asan Medical Center, were evaluated, including 33 metallo-beta-lactamase (MBL) producers and 103 non-CPEs. MHT was performed by using two carbapenem disks (ertapenem and meropenem; Becton Dickinson, USA), three media (Mueller-Hinton agar (MHA), MacConkey agar (MAC), and zinc-enriched MHA), and two inoculums (0.5-McFarland [McF] suspension and a 10-fold dilution of it.) PCR was performed to detect beta-lactamase genes of the MBL, AmpC, and CTX-M types. RESULTS: The sensitivity of MHT for detecting New Delhi metallo-beta-lactamase (NDM) producers was highest using ertapenem and 0.5-McF, 52.0% on MHA and 68.0% on MAC, respectively. NDM-producing Klebsiella pneumoniae (NDMKP) were detected with higher sensitivity on MAC (78.6%) vs. MHA (28.6%) (P=0.016), but VIM-producing Enterobacter, Citrobacter, and Serratia were detected with higher sensitivity on MHA (78.5%) vs. MAC (14.3%) (P=0.004). MBL producers were consistently identified with lower sensitivity using meropenem vs. ertapenem, 39.4% vs. 60.6% (P=0.0156), respectively. The effects of zinc and inoculum size were insignificant. Enterobacter aerogenes producing unspecified AmpC frequently demonstrated false positives, 66.7% with ertapenem and 22.2% with meropenem. CONCLUSIONS: The MHT should be adjusted for the local distribution of species and the carbapenemase type of MBL producers. MAC and ertapenem are preferable for assessing NDMKP, but MHA is better for VIM. Laboratory physicians should be aware of the limited sensitivity of MHT and its relatively high false-positive rate.
Anti-Bacterial Agents/pharmacology
;
Carbapenems/pharmacology
;
DNA, Bacterial/genetics/metabolism
;
Disk Diffusion Antimicrobial Tests
;
Drug Resistance, Bacterial
;
Enterobacteriaceae/drug effects/*enzymology/isolation & purification
;
Enterobacteriaceae Infections/microbiology
;
Humans
;
Multiplex Polymerase Chain Reaction
;
Phenotype
;
beta-Lactamases/genetics/*metabolism
7.Combined Use of the Modified Hodge Test and Carbapenemase Inhibition Test for Detection of Carbapenemase-Producing Enterobacteriaceae and Metallo-beta-Lactamase-Producing Pseudomonas spp..
Wonkeun SONG ; Seong Geun HONG ; Dongeun YONG ; Seok Hoon JEONG ; Hyun Soo KIM ; Han Sung KIM ; Jae Seok KIM ; Il Kwon BAE
Annals of Laboratory Medicine 2015;35(2):212-219
BACKGROUND: We evaluated the combined use of the modified Hodge test (MHT) and carbapenemase inhibition test (CIT) using phenylboronic acid (PBA) and EDTA to detect carbapenemase-producing Enterobacteriaceae (CPE) and metallo-beta-lactamase (MBL)-producing Pseudomonas spp. METHODS: A total of 49 isolates of CPE (15 Klebsiella pneumoniae carbapenemase [KPC], 5 Guiana extended-spectrum beta-lactamase [GES]-5, 9 New Delhi metallo-beta-lactamase [NDM]-1, 5 Verona integron-encoded metallo-beta-lactamase [VIM]-2, 3 imipenem-hydrolyzing beta-lactamase [IMP], and 12 oxacillinase [OXA]-48-like), 25 isolates of MBL-producing Pseudomonas spp. (14 VIM-2 and 11 IMP), and 35 carbapenemase-negative controls were included. The MHT was performed for all isolates as recommended by the Clinical and Laboratory Standards Institute. Enhanced growth of the indicator strain was measured in mm with a ruler. The CIT was performed by directly dripping PBA and EDTA solutions onto carbapenem disks that were placed on Mueller-Hinton agar plates seeded with the test strain. RESULTS: Considering the results of the MHT with the ertapenem disk in Enterobacteriaceae and Pseudomonas spp., the CIT with the meropenem disk in Enterobacteriaceae, and the imipenem disk in Pseudomonas spp., three combined disk tests, namely MHT-positive plus PBA-positive, EDTA-positive, and MHT-positive plus PBA-negative plus EDTA-negative, had excellent sensitivity and specificity for the detection of KPC- (100% sensitivity and 100% specificity), MBL- (94% sensitivity and 100% specificity), and OXA-48-like-producing isolates (100% sensitivity and 100% specificity), respectively. CONCLUSIONS: Combined use of the MHT and CIT with PBA and EDTA, for the detection of CPE and MBL-producing Pseudomonas spp., is effective in detecting and characterizing carbapenemases in routine laboratories.
Bacterial Proteins/antagonists & inhibitors/*metabolism
;
Boronic Acids/chemistry/pharmacology
;
Disk Diffusion Antimicrobial Tests/*methods
;
Edetic Acid/chemistry/pharmacology
;
Enterobacteriaceae/drug effects/*enzymology
;
Enterobacteriaceae Infections/diagnosis
;
Humans
;
Pseudomonas/drug effects/*enzymology
;
Pseudomonas Infections/diagnosis
;
Sensitivity and Specificity
;
beta-Lactamases/chemistry/*metabolism
8.Antimicrobial Resistance Patterns and Integron Carriage of Escherichia coli Isolates Causing Community-Acquired Infections in Turkey.
Aysegul COPUR-CICEK ; Osman Birol OZGUMUS ; Aysegul SARAL ; Cemal SANDALLI
Annals of Laboratory Medicine 2014;34(2):139-144
We aimed to observe antimicrobial resistance patterns and integron carriage of Escherichia coli isolates causing community-acquired infections. Two hundred sixty-eight E. coli strains were obtained from outpatients with various infections at different polyclinics at the 82nd Year of State Hospital in Rize, Turkey. Susceptibility to antimicrobials was tested using a disk diffusion method. The presence of integrons was examined using PCR with specific primers. Positive PCR results were confirmed by sequencing. A broth mating method was used for conjugation assays. Extragenic palindromic-PCR was performed using the oligonucleotide primer BOXA1R. Resistance frequency for ampicillin, trimethoprim/sulfamethoxazole, and tetracycline was determined as 50.6%, 33.5%, and 36.8% respectively. No strains were resistant to amikacin. Seventy isolates were positive for the intI1 gene, of which 49 carried gene cassettes. Eleven isolates were positive for the intI2 gene, eight of which carried gene cassettes. Seven gene cassettes (dfrA1, dfrA5, dfrA7, dfrA17, aadA1, aadA5, and sat2) were predominantly harbored in integrons. We detected conjugative plasmids harboring integrons in two E. coli strains. Four strain clusters were yielded by BOX-PCR fingerprints showing that they were clonally related. No apparent relationship occurred among class 1 and 2 integron-carrying strains. We conclude that integrons are widespread in genetically variable E. coli strains and will continue to mediate dissemination of resistance genes in the community.
Anti-Bacterial Agents/*pharmacology
;
Community-Acquired Infections/*microbiology
;
Disk Diffusion Antimicrobial Tests
;
Drug Resistance, Bacterial
;
Escherichia coli/*drug effects/isolation & purification
;
Escherichia coli Proteins/*genetics
;
Humans
;
Integrases/genetics
;
Polymerase Chain Reaction
;
Turkey
9.Performance of Kiestra Total Laboratory Automation Combined with MS in Clinical Microbiology Practice.
Nico T MUTTERS ; Caspar J HODIAMONT ; Menno D DE JONG ; Hendri P J OVERMEIJER ; Mandy VAN DEN BOOGAARD ; Caroline E VISSER
Annals of Laboratory Medicine 2014;34(2):111-117
BACKGROUND: Microbiological laboratories seek technologically innovative solutions to cope with large numbers of samples and limited personnel and financial resources. One platform that has recently become available is the Kiestra Total Laboratory Automation (TLA) system (BD Kiestra B.V., the Netherlands). This fully automated sample processing system, equipped with digital imaging technology, allows superior detection of microbial growth. Combining this approach with matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MS) (Bruker Daltonik, Germany) is expected to enable more rapid identification of pathogens. METHODS: Early growth detection by digital imaging using Kiestra TLA combined with MS was compared to conventional methods (CM) of detection. Accuracy and time taken for microbial identification were evaluated for the two methods in 219 clinical blood culture isolates. The possible clinical impact of earlier microbial identification was assessed according to antibiotic treatment prescription. RESULTS: Pathogen identification using Kiestra TLA combined with MS resulted in a 30.6 hr time gain per isolate compared to CM. Pathogens were successfully identified in 98.4% (249/253) of all tested isolates. Early microbial identification without susceptibility testing led to an adjustment of antibiotic regimen in 12% (24/200) of patients. CONCLUSIONS: The requisite 24 hr incubation time for microbial pathogens to reach sufficient growth for susceptibility testing and identification would be shortened by the implementation of Kiestra TLA in combination with MS, compared to the use of CM. Not only can this method optimize workflow and reduce costs, but it can allow potentially life-saving switches in antibiotic regimen to be initiated sooner.
Automation, Laboratory
;
Candida albicans/genetics/*isolation & purification
;
Disk Diffusion Antimicrobial Tests
;
Gram-Negative Bacteria/genetics/*isolation & purification
;
Gram-Positive Bacteria/genetics/*isolation & purification
;
Humans
;
RNA, Ribosomal, 16S/chemistry/genetics
;
Retrospective Studies
;
Sequence Analysis, RNA
;
*Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
10.In vitro effects of Salvia officinalis L. essential oil on Candida albicans.
Tularat SOOKTO ; Theerathavaj SRITHAVAJ ; Sroisiri THAWEBOON ; Boonyanit THAWEBOON ; Binit SHRESTHA
Asian Pacific Journal of Tropical Biomedicine 2013;3(5):376-380
OBJECTIVETo determine the anticandidal activities of Salvia officinalis L. (S. officinalis) essential oil against Candida albicans (C. albicans) and the inhibitory effects on the adhesion of C. albicans to polymethyl methacrylate (PMMA) resin surface.
METHODSDisc diffusion method was first used to test the anticandidal activities of the S. officinalis L. essential oil against the reference strain (ATCC 90028) and 2 clinical strains of C. albicans. Then the minimal inhibitory concentration (MIC) and minimal lethal concentration (MLC) were determined by modified membrane method. The adhesion of C. albicans to PMMA resin surface was assessed after immersion with S. officinalis L. essential oil at various concentrations of 1×MIC, 0.5×MIC and 0.25×MIC at room temperature for 30 min. One-way ANOVA was used to compare the Candida cell adhesion with the pretreatment agents and Tukey's test was used for multiple comparisons.
RESULTSS. officinalis L. essential oil exhibited anticandidal activity against all strains of C. albicans with inhibition zone ranging from 40.5 mm to 19.5 mm. The MIC and MLC of the oil were determined as 2.780 g/L against all test strains. According to the effects on C. albicans adhesion to PMMA resin surface, it was found that immersion in the essential oil at concentrations of 1×MIC (2.780 g/L), 0.5×MIC (1.390 g/L) and 0.25×MIC (0.695 g/L) for 30 min significantly reduced the adhesion of all 3 test strains to PMMA resin surface in a dose dependent manner (P<0.05).
CONCLUSIONSS. officinalis L. essential oil exhibited anticandidal activities against C. albicans and had inhibitory effects on the adhesion of the cells to PMMA resin surface. With further testing and development, S. officinalis essential oil may be used as an antifungal denture cleanser to prevent candidal adhesion and thus reduce the risk of candida-associated denture stomatitis.
Antifungal Agents ; chemistry ; pharmacology ; Candida albicans ; drug effects ; Disk Diffusion Antimicrobial Tests ; Microbial Sensitivity Tests ; Oils, Volatile ; chemistry ; pharmacology ; Salvia officinalis ; chemistry


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