1) A study of 1,991 Group B Streptococcus (GBS) isolates collected between 2008-2009 from a hospital in Philadelphia found no isolates exhibited non-penicillin susceptibility based on broth microdilution testing.
2) Three screening methods for detecting non-penicillin susceptible GBS were evaluated: oxacillin and ceftizoxime disk tests and oxacillin screening agar. The disk tests showed high false positive rates while the agar was 100% specific but sensitivity was unknown.
3) Based on the currently very low prevalence of non-penicillin susceptible GBS and lack of a high-performance screening method, routine screening for resistance is not presently recommended.
Incidence rate of multidrug-resistant organisms in a tertiary care hospital, ...Apollo Hospitals
Antimicrobial resistance to microorganisms is a growing public health concern globally, especially in developing countries. This study was conducted to study the incidence rate of multidrug-resistant organisms with their antibiotic sensitivity pattern.
Background and study aim: During last two decades, there has been a world-wide trend in increasing occurrence of enterococcal infections in the hospitals. The aim of present study was to determine the spectrum of enterococcal infections, species prevalence, antimicrobial and characteristics of vancomycin resistant enterococci (VRE) in a tertiary care hospital, Eastern India.
Patients and Methods: Between January 2013 and July 2014, 152 Enterococcus species were obtained from clinical samples. Enterococci were identified using standard biochemical tests. Antimicrobial susceptibility was tested by Kirby-Bauer disk diffusion according to Clinical resistance
& Laboratory Standards Institute (CLSI) guidelines.VRE agar base was used to screen VRE isolates. Minimum inhibitory concentration (MIC) values of VRE isolates were determined using Epsilometer-test. VRE isolates were also examined by PCR to detect vanA gene.
Results: From 1602 clinical samples, 961 (60%) were culture positive and 152 (15.8%) enterococcal isolates were obtained. Most common species isolated was E. faecalis (63.8%) followed by E. faecium (35.5%). Majority of enterococcal infections were detected from ICUs and surgical wards and clinically presented as UTIs. Disk diffusion method showed 67.1% were resistant to penicillin, 61.2% ampicillin, 58.5% ciprofloxacin, 46.7% high-level gentamicin, 42. 8% high-level streptomycin, 7.9% teicoplanin and none to linezolid. Twenty (13.2%) enterococcal isolates were vancomycin resistant in VRE screen and disk diffusion method. Epsilometer-test of VRE isolates showed 8 (40%) isolates were resistant and 9 (45%) were intermediately resistant. From 20 VRE isolates, six showed VanA and two VanB phenotypes and all six VanA phenotypes had vanA gene cluster.
Conclusion: More accurate and reliable MIC determination tests should be performed in all suspected VRE isolates. Confirmatory PCR is required for identifying resistant gene cluster.
Key words: Enterococci, E. faecalis, E. faecium, VRE, vanA gene
Incidence rate of multidrug-resistant organisms in a tertiary care hospital, ...Apollo Hospitals
Antimicrobial resistance to microorganisms is a growing public health concern globally, especially in developing countries. This study was conducted to study the incidence rate of multidrug-resistant organisms with their antibiotic sensitivity pattern.
Background and study aim: During last two decades, there has been a world-wide trend in increasing occurrence of enterococcal infections in the hospitals. The aim of present study was to determine the spectrum of enterococcal infections, species prevalence, antimicrobial and characteristics of vancomycin resistant enterococci (VRE) in a tertiary care hospital, Eastern India.
Patients and Methods: Between January 2013 and July 2014, 152 Enterococcus species were obtained from clinical samples. Enterococci were identified using standard biochemical tests. Antimicrobial susceptibility was tested by Kirby-Bauer disk diffusion according to Clinical resistance
& Laboratory Standards Institute (CLSI) guidelines.VRE agar base was used to screen VRE isolates. Minimum inhibitory concentration (MIC) values of VRE isolates were determined using Epsilometer-test. VRE isolates were also examined by PCR to detect vanA gene.
Results: From 1602 clinical samples, 961 (60%) were culture positive and 152 (15.8%) enterococcal isolates were obtained. Most common species isolated was E. faecalis (63.8%) followed by E. faecium (35.5%). Majority of enterococcal infections were detected from ICUs and surgical wards and clinically presented as UTIs. Disk diffusion method showed 67.1% were resistant to penicillin, 61.2% ampicillin, 58.5% ciprofloxacin, 46.7% high-level gentamicin, 42. 8% high-level streptomycin, 7.9% teicoplanin and none to linezolid. Twenty (13.2%) enterococcal isolates were vancomycin resistant in VRE screen and disk diffusion method. Epsilometer-test of VRE isolates showed 8 (40%) isolates were resistant and 9 (45%) were intermediately resistant. From 20 VRE isolates, six showed VanA and two VanB phenotypes and all six VanA phenotypes had vanA gene cluster.
Conclusion: More accurate and reliable MIC determination tests should be performed in all suspected VRE isolates. Confirmatory PCR is required for identifying resistant gene cluster.
Key words: Enterococci, E. faecalis, E. faecium, VRE, vanA gene
Isolation, Characterization, and Antibiotics Resistance Profile of Staphyloco...AdeyemiKayode2
Isolation, Characterization, and Antibiotics Resistance Profile of Staphylococci from Indoor Air of the Students’ Halls of Residence at the Obafemi Awolowo University, Ile Ife, Nigeria.
Maternal colonization epidemiology studies - implications for vaccine studies...WAidid
The slideset is an overview on lessons learnt from maternal colonization epidemiology studies focused on:
- Association of maternal recto-vaginal GBS colonization and invasive GBS disease
- Correlate of protection against GBS colonization in pregnant women
The slideset underlines, moreover, the potential of GBS vaccine protecting against colonization:
- Could protect term and preterm (with early vaccination) newborns independent of antibody transfer.
- Protecting against maternal complications, including GBS associated chorioamnionitis and stillbirths.
Variable transcriptional adaptation between the laboratory (H37Rv) and clinic...Santhi Devasundaram
The remarkable success of M. tuberculosis as a pathogen is largely due to its ability to
persist within the host for long periods. To develop the effective intervention strategies, understanding the biology
of persistence is highly required. Accumulating evidences showed oxygen deprivation (hypoxia) as a potential
stimulus for triggering the transition of M. tuberculosis to a non-replicating persistent state analogous to
latency in vivo. To date, in vitro hypoxia experimental models used the laboratory adapted isolate H37Rv and
very little is known about the behavior of clinical isolates that are involved during disease outbreaks. Hence,
we compared the transcription profiles of H37Rv and two south Indian clinical isolates (S7 and S10) under hypoxia
to find differences in gene expression pattern.
Presented by Dr. Brecher at the 40th Annual Symposium "Diagnostic and Clinical Challenges of 20th Century Microbes", held on Nov 18, 2010 in Philadelphia.
Staphylococcus lugdunensis is a coagulase-negative staphylococci. The organism is found as a skin commensal in healthy individuals. S. lugdunensis has been implicated in invasive diseases. The mecA gene has been reported in several data, the first in a neonate with MRSL that produces an alternative penicillin binding protein (PBP2A).
Isolation, Characterization, and Antibiotics Resistance Profile of Staphyloco...AdeyemiKayode2
Isolation, Characterization, and Antibiotics Resistance Profile of Staphylococci from Indoor Air of the Students’ Halls of Residence at the Obafemi Awolowo University, Ile Ife, Nigeria.
Maternal colonization epidemiology studies - implications for vaccine studies...WAidid
The slideset is an overview on lessons learnt from maternal colonization epidemiology studies focused on:
- Association of maternal recto-vaginal GBS colonization and invasive GBS disease
- Correlate of protection against GBS colonization in pregnant women
The slideset underlines, moreover, the potential of GBS vaccine protecting against colonization:
- Could protect term and preterm (with early vaccination) newborns independent of antibody transfer.
- Protecting against maternal complications, including GBS associated chorioamnionitis and stillbirths.
Variable transcriptional adaptation between the laboratory (H37Rv) and clinic...Santhi Devasundaram
The remarkable success of M. tuberculosis as a pathogen is largely due to its ability to
persist within the host for long periods. To develop the effective intervention strategies, understanding the biology
of persistence is highly required. Accumulating evidences showed oxygen deprivation (hypoxia) as a potential
stimulus for triggering the transition of M. tuberculosis to a non-replicating persistent state analogous to
latency in vivo. To date, in vitro hypoxia experimental models used the laboratory adapted isolate H37Rv and
very little is known about the behavior of clinical isolates that are involved during disease outbreaks. Hence,
we compared the transcription profiles of H37Rv and two south Indian clinical isolates (S7 and S10) under hypoxia
to find differences in gene expression pattern.
Presented by Dr. Brecher at the 40th Annual Symposium "Diagnostic and Clinical Challenges of 20th Century Microbes", held on Nov 18, 2010 in Philadelphia.
Staphylococcus lugdunensis is a coagulase-negative staphylococci. The organism is found as a skin commensal in healthy individuals. S. lugdunensis has been implicated in invasive diseases. The mecA gene has been reported in several data, the first in a neonate with MRSL that produces an alternative penicillin binding protein (PBP2A).
Antibiotic Susceptibility Pattern of Pyogenic Bacterial Isolates in Sputum.IOSR Journals
Drugs Have Been Used For The Treatment Of Infectious Diseases Since 17th Century , However
Chemotherapy As A Science Has Began With Paul Ehrlich In The First Decade Of 20th Century . Paul Ehrlich
(1854-1915) Was One Of The Earliest Pioneers In The Field Of Antimicrobial Chemotherapy .1Ehrlich
Formulated The Principles Of “Selective Toxicity” ,I.E; Selective Inhibition Of The Growth Of Microorganisms
Without Damage To The Host.2 Resistance Has Been Documented Not Only Against Antibiotics Of
Natural And Semi- Synthetic Origin , But Also Against Purely Synthetic Compounds (Flouroquinolone) Or
Those Which Do Not Even Enter The Cells (Vancomycin) .3 However , The Euphoria Over The Potential
Conquest Of Infectious Diseases Was Short-Lived .Almost As Soon As Antibacterial Drugs Were Deployed ,
Bacteria Responded By Manifesting Various Forms Of Resistance.4 Considered As “Wonder Drugs”
Antibiotics Are Often Prescribed Inappropriately And Inadequately And Have Thus Became One Of The
Highly Abused Agents.5
The prevalence of extended spectrum beta-lactamases (ESBLs) among Escherichia...Open Access Research Paper
The prevalence of extended spectrum β-lactamases among 246 clinical isolates from Abia State University teaching Hospital patients was investigated. The isolates were made up of 134 Escherichia coli and 112 Klebsiella species. Antimicrobial susceptibility of the isolates was determined by the disc diffusion method. ESBL phenotypes were determined by the double disc synergy method using ceftazidime, cefotaxime, ceftriaxone and co-amoxiclav. Out of the 246 isolates, 125 (50.8%) were ESBL producers, made up of 62(50.8%) E. coli and 63 (50.4%) Klebsiella isolates. Seventeen (54.8%) of the ESBL producing E. coli isolates were from in-patients while 45 (47.9%) were from out-patients. For the ESBL positive Klebsiella spp., 14 (45.2%) and 49 (52.1%) were from in-patients and out-patients respectively. ESBL producing isolates were also found to be more prevalent among the female patients (72.8%) than among the male patients (27.2%). The isolates also expressed high rates of resistance to other classes of antibiotics tested. However, Amikacin was found to have excellent performance against the urinary isolates tested and therefore is recommended for the treatment of infections caused by Escherichia coli and Klebsiella species. This study shows high prevalence of ESBL producing E. coli and Klebsiella isolates clinical samples of patients attending the Abia State University Teaching Hospital Aba, Abia State Nigeria.
SALMONELLA ARIZOANE: AN UNCOMMON UROPATHOGEN?Nuhu Tanko
Salmonella arizonae is usually an uncommon uropathogen from many studies. But from this study, it was the second most prevalent uropathogen after E.coli.
The seminar is about this article: Containment of a Methicillin-resistant Staphylococcus aureus outbreak in a Neonatal Intensive Care Unit.
I described
The effect of silver nanoparticles on Staphylococcus epidermidis biofilm biom...Nanomedicine Journal (NMJ)
Abstract
Objective(s):
Bacterial biofilm has been considered responsible for many deaths and high health costs worldwide. Their better protection against antibacterial agents compared to free living cells leads to poor treatment efficiency. Nanotechnology is promising approach to combat biofilm infections. The aim of the present study was to eradicate Staphylococcus epidermidis biofilm with silver nanoparticles (SNPs).
Materials and Methods:
SNPs were used at different concentrations (two fold dilutions) and incubation times (24, 48, 72 h). The crystal violet staining and pour plate assays were used to assess biofilm biomass and bacterial viability, respectively. The ability of SNPs on biofilm matrix eradication was assessed through optical density ratio (ODr). Positive control was defined as an ODr =1.0.
Results:
The crystal violet assay indicated that the biofilm matrixes were intact at different concentrations of SNOs and incubation times. There were no significant differences between these parameters (P >0.05). Bacterial enumeration studies revealed that higher concentrations of SNPs were more effective in killing bacteria than lower ones. Although, longer incubation times led to enhancement of anti-biofilm activity of SNPs.
Conclusion:
The anti-biofilm activity of SNPs was concentration- and time-dependent. The results of this study highlighted that SNPs were effective against cell viability; however they were ineffective against biomass.
DOI: 10.21276/ijlssr.2016.2.3.5
ABSTRACT- Purpose: Multidrug resistant organisms are on rise. Various enzymes present in the organisms are
responsible for this resistance. Detection of these enzymes become challenging if organisms harbor multiple enzymes.
This study was done to find the prevalence of various enzymes at our tertiary care hospital.
Materials and methods: Extended spectrum beta lactamases (ESBL) detection was done by screening method followed
by two phenotypic confirmatory methods (double disc synergy and disc potentiation method). Carbapenems (imipenem,
meropenem) resistant strain were analyzed for metallo beta lactamases (MBL) and carbapenemases (KPC) using
combined disc test and modified Hodge test. Amp C detection was done by using cefoxitin disc on heavy lawn of E. coli
ATCC 25922. Distortion of the zone size on the streaked line of test was taken as positive for Amp C.
Results: 87.15% were screened positive for ESBL and confirmed cases were 36.80%. Carbapenem resistant was 31.86%,
MBL was 7.52%, KPC was 0.82 %, Amp C in 0.23%.
Conclusions: There is high prevalence of ESBL. Detection of these enzymes is important in routine diagnostics for
treatment. Co-expression of multiple enzymes was detected in this study. Judicious and rational use of antibiotics is
required which might lead to decrease in emergence of resistance. Also knowledge of the prevalence of these enzymes
helps in empirical antibiotic therapy and in infection control purpose.
Key-words- Multidrug resistant, ESBL, MBL, KPC, Amp C
A total number of 74 coagulase negative Staphylococci were isolated from orthopaedic patients in Ahmadu Bello University Teaching Hospital, Zaria, Nigeria. They were further characterized into various Staphylococci species using API STAPH identification kit: Staph xylosus (31.1%), Staph lentus (10.8%), Staph hominis (10.8%), Staph cohnii cohnii (5.4%), Staph epidermidis (4.1%) others were Staph cohnii ureal., Staph hyicus, Staph lugdunensis (2.7% each) Staph caprae , Staph capitis, Staph haemolyticus, Staph scuiri, Staph chromogenes and Staph warneri (1.4% each). Microcossus spp was 8.2% while 13.5% isolates were undetermined. Kirby Baurer disk method was used for the antibiotics susceptibility test, the result showed gentamicin and ciprofloxacin to be most active (96.6%), followed by vancomycin (93.1) and pefloxacin (87.9). The isolates were resistant to ampicillin (96.6), amoxicillin clavulanic acid (65.5%), clindamycin 41.4%). The aim of this study is to classify the coagulase negative Staphylococci isolates into species and to determine their antibiotic susceptibility
2. breakpoint proposed by Kimura and colleagues (5). None of
the tested GBS strains grew on the oxacillin screening agar.
To confirm that GBS isolates with the smallest oxacillin disk
zone sizes were not cryptic PNSGBS, despite penicillin MICs of
Յ0.06 g/ml, four isolates with zone sizes of 11, 12, 12, and 12 mm
were sequenced in the pbp2x region. None of these isolates con-
tained mutations associated with penicillin resistance.
Our study shows two important findings, that PNSGBS are
not emerging in our patient population and that a proposed
disk test (5) to detect PNSGBS has an unacceptably high false-
positive rate. Since our study was adequately powered to detect
a very low prevalence rate of PNSGBS, with a 95% chance of
detecting the 0.39% PNSGBS prevalence rate found in a re-
cent survey (2), we can conclude that emerging PNSGBS is
extremely unlikely in our patient population.
Kimura and colleagues (5) recently reported that disk diffu-
sion testing with the combination of oxacillin, ceftizoxime, and
ceftibuten disks is a useful screening method for the detection
of PNSGBS. Although they included 32 PNSGBS isolates in
their study, only 16 penicillin-susceptible isolates were tested
by them. Using a much larger population of penicillin-suscep-
tible GBS isolates, we found that their proposed method is
nonspecific, with true specificities of 77 and 46% for cefti-
zoxime and oxacillin, respectively. Based on the highest reli-
able prevalence of PNSGBS reported, 0.7% (6), and an as-
sumption of 100% sensitivity, the positive predictive values of
the suggested breakpoints would be 1 and 3%, respectively, for
oxacillin and ceftizoxime. Whether the oxacillin screening agar
test used by us, which was 100% specific, is of adequate sen-
sitivity requires study with a larger number of PNSGBS strains.
Based on the currently very low PNSGBS prevalence and the
absence of a known high-performance screening method, rou-
tine screening for these strains is not presently indicated.
Eric Chen, Matthew Delfiner, Shane Tepper, and Shannon
McGettigan provided excellent technical assistance, and the Clini-
cal Microbiology Staff of the Hospital of the University of Pennsyl-
vania kindly provided us with GBS isolates.
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Nizet, and B. W. Beall. 2008. Point mutation in the group B streptococcal
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FIG. 1. Distribution of zone diameters of oxacillin (A) and ceftizoxime (B) disk tests for 1,991 penicillin-susceptible GBS strains. Note
discontinuous axes.
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