scholarly journals Streptococcus agalactiae in pregnant women: serotype and antimicrobial susceptibility patterns over five years in Eastern Sicily (Italy)

2020 ◽  
Vol 39 (12) ◽  
pp. 2387-2396
Author(s):  
Carlo Genovese ◽  
Floriana D’Angeli ◽  
Valentina Di Salvatore ◽  
Gianna Tempera ◽  
Daria Nicolosi
Keyword(s):  
Pregnant Women ◽  
Antimicrobial Susceptibility ◽  
Streptococcus Agalactiae ◽  
Late Onset ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Resistance Pattern ◽  
Disk Diffusion Method ◽  
Defibrinated Sheep Blood ◽  
Disk Diffusion Test

AbstractStreptococcus agalactiae (also known Group B Streptococcus or GBS) represents the main pathogen responsible for early- and late-onset infections in newborns. The present study aimed to determine the antimicrobial susceptibility pattern and the capsular serotypes of GBS isolated in Eastern Sicily over 5 years, from January 2015 to December 2019. A total of 3494 GBS were isolated from vaginal swabs of pregnant women (37–39 weeks), as recommended by the Centers for Disease Control and Prevention. Capsular polysaccharide’s typing of GBS was determined by a commercial latex agglutination test containing reagents to serotypes I–IX. The antimicrobial resistance pattern of GBS was determined through the disk diffusion method (Kirby-Bauer) and the double-disk diffusion test on Mueller-Hinton agar plates supplemented with 5% defibrinated sheep blood, according to the guidelines of the Clinical and Laboratory Standards Institute. Serotypes III (1218, 34.9%) and V (1069, 30.6%) were the prevalent colonizers, followed by not typable (570, 16.3%) and serotypes Ia (548, 15.7%), Ib (47, 1.3%), II (40, 1.1%), and IV (2, 0.1%). All 3494 clinical isolates were susceptible to cefditoren and vancomycin. Resistance to penicillin, ampicillin, levofloxacin, clindamycin, and erythromycin was observed in 6 (0.2%), 5 (0.1%), 161 (4.6%), 1090 (31.2%), and 1402 (40.1%) of the strains, respectively. Most of erythromycin-resistant GBS (1090/1402) showed the cMLSB phenotype, 276 the M phenotype, and 36 the iMLSB phenotype. Our findings revealed a higher prevalence of serotype III and a relevant resistance rate, among GBS strains, to the most frequently used antibiotics in antenatal screening.

Staphylococci isolated from animals and food with phenotypically reduced susceptibility to β-lactamase-resistant β-lactam antibiotics

2004 ◽  
Vol 52 (1) ◽  
pp. 7-17 ◽  
Author(s):  
Éva J. Kaszanyitzky ◽  
Zsuzsanna Egyed ◽  
Sz. Jánosi ◽  
Judit Keserű ◽  
Zsuzsanna Gál ◽  
...  
Keyword(s):  
Inhibition Zone ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Resistance Pattern ◽  
Coagulase Negative Staphylococci ◽  
Disk Diffusion Method ◽  
Disk Diffusion Test ◽  
Methicillin Resistant ◽  
Zone Diameter ◽  
Mrsa Strains

The antibiotic resistance pattern of 1921 Staphylococcus strains isolated from animals and food within the last two years were examined using diffusion tests. Among them there were only 35 strains of S. aureus having an inhibition zone diameter of 15 mm or less, and 4 strains of coagulase-negative staphylococci (CNS) having a zone diameter of 18 mm or less to 1-µg oxacillin disk. These 39 strains were examined also by E-test to oxacillin and for the detection of the mecA gene by PCR in order to determine whether they might be real methicillin-resistant staphylococci. Among the 39 strains there were only two that were susceptible to penicillin by disk diffusion method; however, further examination by the penicillinase test showed that they produced ß-lactamase. While 19 (15 S. aureus, 4 CNS) strains were resistant and 7 strains were intermediate to oxacillin in disk diffusion test, the E-test gave 8 resistant and 5 intermediate results. Six out of the 8 oxacillin-resistant strains examined by disk diffusion and E-test harboured the mecA gene. Thus only 6 out of the examined 1921 strains proved to be mecA positive. These methicillin-resistant, mecA-positive strains (5 of the S. aureus strains and 1 of the S. epidermidis) originated from two dairy herds. The results prove that methicillin-resistant S. aureus (MRSA) strains in animals are really rare in Hungary. Eighteen strains were chosen and screened for minimal inhibitory concentration (MIC) of oxacillin with or without clavulanic acid or sulbactam, and three of them produced methicillinase enzyme.

scholarly journals MOLECULAR IDENTIFICATION AND ANTIMICROBIAL RESISTANCE PATTERN OF SEVEN CLINICAL ISOLATES OF Nocardia spp. IN BRAZIL

2015 ◽  
Vol 57 (3) ◽  
pp. 251-256 ◽  
Author(s):  
Larissa Anuska Zeni CONDAS ◽  
Márcio Garcia RIBEIRO ◽  
Marisol Domingues MURO ◽  
Agueda Palmira Castagna de VARGAS ◽  
Tetsuhiro MATSUZAWA ◽  
...  
Keyword(s):  
Antimicrobial Susceptibility ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Resistance Pattern ◽  
Sequencing Analysis ◽  
Disk Diffusion Method ◽  
Antimicrobial Susceptibility Pattern ◽  
Nocardia Farcinica ◽  
Minimal Concentration ◽  
Immunosuppressive Diseases

Nocardia is a ubiquitous microorganism related to pyogranulomatous infection, which is difficult to treat in humans and animals. The occurrence of the disease is on the rise in many countries due to an increase in immunosuppressive diseases and treatments. This report of cases from Brazil presents the genotypic characterization and the antimicrobial susceptibility pattern using the disk-diffusion method and inhibitory minimal concentration with E-test® strips. In summary, this report focuses on infections in young adult men, of which three cases were cutaneous, two pulmonary, one neurological and one systemic. The pulmonary, neurological and systemic cases were attributed to immunosuppressive diseases or treatments. Sequencing analysis of the 16S rRNA segments (1491 bp) identified four isolates of Nocardia farcinica, two isolates of Nocardia nova and one isolate of Nocardia asiatica. N. farcinica was involved in two cutaneous, one systemic and other pulmonary cases; N. nova was involved in one neurological and one pulmonary case; and Nocardia asiatica in one cutaneous case. The disk-diffusion antimicrobial susceptibility test showed that the most effective antimicrobials were amikacin (100%), amoxicillin/clavulanate (100%), cephalexin (100%) and ceftiofur (100%), while isolates had presented most resistance to gentamicin (43%), sulfamethoxazole/trimethoprim (43%) and ampicillin (29%). However, on the inhibitory minimal concentration test (MIC test), only one of the four isolates of Nocardia farcinica was resistant to sulfamethoxazole/trimethoprim.

scholarly journals Vibrio alginolyticusAssociated Chronic Myringitis Acquired in Mediterranean Waters of Turkey

2015 ◽  
Vol 2015 ◽  
pp. 1-3 ◽  
Author(s):  
Burak Ekrem Citil ◽  
Serhan Derin ◽  
Funda Sankur ◽  
Murat Sahan ◽  
Mahmut Ugur Citil
Keyword(s):  
Antimicrobial Susceptibility ◽  
Vibrio Parahaemolyticus ◽  
Vibrio Alginolyticus ◽  
Clinical Isolates ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
External Ear ◽  
Disk Diffusion Method ◽  
Ear Infections

Vibrio alginolyticuswas originally classified as biotype 2 ofVibrio parahaemolyticus. Most clinical isolates are recovered from superficial wounds or the external ear infections.V. alginolyticusis acknowledged to be nearly nonpathogenic in humans. The reason for presence ofV. alginolyticus’s virulence is uncertain. We describe a chronic myringitis case in a 47-year-old female due toV. alginolyticus. According to her anamnesis, it was detected that she had sea bathing history in Mugla Coast in Turkey. Pure isolation ofV. alginolyticuswas obtained from external auditory canal’s culture. Investigation and antimicrobial susceptibility of the isolate were performed by the automatized BD Phoenix system and Kirby-Bauer disk diffusion method, respectively. The bacteria were sensitive to all antibiotics. This case was presented to pay attention toVibrio alginolyticusinfections.

scholarly journals In vitro antimicrobial screening of Lycoperdon lividium and determination of the ethanol extract composition by gas chromatography/mass spectrometry

2016 ◽  
Vol 11 (2) ◽  
pp. 389 ◽  
Author(s):  
Kerem Canli ◽  
Ergin Murat Altuner ◽  
Ilgaz Akata ◽  
Yavuz Turkmen ◽  
Ugur Uzek
Keyword(s):  
Antimicrobial Activity ◽  
Video Clip ◽  
Ethanol Extract ◽  
Disk Diffusion ◽  
Gas Chromatography Mass Spectrometry ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
Disk Diffusion Test ◽  
Wide Range

<p class="Abstract">The aim of this study was to investigate the antimicrobial activity of <em>Lycoperdon lividium</em> against 17 bacterial and 1 fungal strains and analyse the composition of ethanol extracts by GC/MS. The in vitro antimicrobial activity of <em>L. lividium</em> extracts having 15 mg/mL concentration was assessed against a wide range of strains by disk diffusion method. The ethanol extract of <em>L. lividium</em> had antimicrobial activity against several microorganism tested, but it was active especially against <em>S. carnosus</em>. The results obtained herein indicate that <em>L. lividium</em> contains several active metabolites.</p><p class="Abstract">Video clip</p><p><a href="https://youtube.com/v/ymWOQBeNN84">Disk diffusion test</a>: 7 min 11 sec</p>

scholarly journals Performance Evaluation of BD Phoenix NMIC-413 Antimicrobial Susceptibility Testing Panel for Imipenem, Meropenem, and Ertapenem Against Clinical Carbapenem-Resistant and Carbapenem-Susceptible Enterobacterales

2021 ◽  
Vol 8 ◽  
Author(s):  
Jingjia Zhang ◽  
Peiyao Jia ◽  
Ying Zhu ◽  
Ge Zhang ◽  
Yingchun Xu ◽  
...  
Keyword(s):  
Antimicrobial Susceptibility ◽  
Susceptibility Testing ◽  
Antimicrobial Susceptibility Testing ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Screening Methods ◽  
Major Error ◽  
Disk Diffusion Method ◽  
Suitable Alternative ◽  
Carbapenem Resistant

Purpose: The infection of carbapenem-resistant Enterobacterales (CRE) has become a major clinical and healthcare problem worldwide. The screening methods of CRE have been extensively developed but still need improving [e.g., tests with accurate and simple minimum inhibitory (MICs)]. In this study, the performance of the BD Phoenix NMIC-413 AST panel was evaluated against clinical CRE and carbapenem-susceptible Enterobacterales (CSE) in China. The panel was first evaluated in the Chinese clinical lab.Methods: Antimicrobial susceptibility testing of 303 clinical Enterobacterales isolates were conducted by broth microdilution (BMD), Phoenix NMIC-413 AST panel, and disk diffusion method for imipenem, ertapenem, and meropenem. Considering BMD is a gold standard, essential agreement (EA), categorical agreement (CA), minor error (MIE), major error (ME), and very major error (VME) were determined according to CLSI guidelines. CA and EA &gt; 90%, ME &lt;3%, and VME &lt;1.5% were considered as acceptable criteria. Polymerase chain reaction and sanger sequencing were performed to determine the β-lactamase genotypes of CRE isolates.Results: Three hundred and three isolates included 195 CREs and 108 CSEs were enrolled according to the BMD-MIC values of three carbapenems. Tested CREs showing 100 blaKPC−2-positive organisms, 31 blaIMP-positive organisms, 28 blaNDM-positive organisms, 5 blaVIM-positive organisms, 2 both blaIMP and blaVIM-positive organisms, 2 blaOXA−48-positive organisms, and 27 isolates without carbapenemase genes. For the Phoenix NMIC-413 method, CA and EA rates &gt;93%, MIE rates &lt;5%, ME rates &lt;1.75%, and VME rates were 0%, across the three drugs. For the disk diffusion method, the CA rates for three drugs were all &gt;93%, while the MIE and ME rates were all &lt;5 and &lt;3%, respectively. VME rate was 3.28% for imipenem, exceeded the cut-off value specified by CLSI M52, 0 and 0.56% for ertapenem and meropenem, separately.Conclusion: Based on the genomic data, the detection of CRE and CSE was more reliable using the BD Phoenix NMIC-413 panel compared to the BMD and disk approaches. Therefore, our study supports the use of BD Phoenix NMIC-413 panel as a suitable alternative to BMD for the detection of carbapenem resistant isolates in a clinical setting.

scholarly journals Evaluation of different phenotypic methods for the detection of methicillin resistant Staphylococcus aureus and antimicrobial susceptibility pattern of MRSA

2017 ◽  
Vol 4 (9) ◽  
pp. 3297 ◽  
Author(s):  
Sheetal Sharma ◽  
Preeti Srivastava ◽  
Anjali Kulshrestha ◽  
Ameer Abbas
Keyword(s):  
Staphylococcus Aureus ◽  
Sensitivity And Specificity ◽  
Antimicrobial Susceptibility ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
Phenotypic Methods ◽  
Cefoxitin Disk ◽  
Cefoxitin Disk Diffusion

Background: Rapid and accurate detection of methicillin resistant Staphylococcus aureus (MRSA) is an important role of clinical microbiology laboratories to avoid treatment failure. The aim of this study was to compare conventional methods against the cefoxitin disc diffusion method to determine the best phenotypic method. Methods: Study was carried out in the Department of Microbiology, National Institute of Medical Sciences & Research, Jaipur (India), between July 2016 – December 2016. The methods included were Oxacillin E-test MIC, Oxacillin screen agar, Oxacillin disk diffusion, Cefoxitin disk diffusion and CHROMagar- MRSA methods. Antimicrobial susceptibility performed as per CLSI guidelines.Results: Out of 142 isolates of S. aureus, fifty three (37.32%) strains of MRSA were isolated from clinical specimen. E-MIC test was selected as gold standard method. The sensitivity and specificity of Oxacillin screen agar and CHROMagar-MRSA were same 98.07% and 97.80%, respectively. The sensitivity and specificity of oxacillin disk diffusion were 94.23% and 98.89%. Fifty three strains of S. aureus were MRSA by cefoxitin disk diffusion method and Oxacillin Ezy MIC test. The sensitivity and specificity of cefoxitin disk diffusion method and Oxacillin Ezy MIC method was 100% and 100% respectively. All isolates including MRSA were susceptible to Vancomycin and Linezolid. Conclusions: All phenotypic methods had high sensitivity and specificity for detection of MRSA. However, cefoxitin disk diffusion method in comparison to other methods had higher sensitivity and specificity. 

scholarly journals Use of an Oxacillin Disk Screening Test for Detection of Penicillin- and Ceftriaxone-Resistant Pneumococci

1999 ◽  
Vol 37 (4) ◽  
pp. 1178-1181 ◽  
Author(s):  
Louise P. Jetté ◽  
Christian Sinave
Keyword(s):  
Antimicrobial Agents ◽  
Clinical Laboratory ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
National Committee ◽  
Zone Of Inhibition ◽  
Diffusion Test ◽  
Disk Diffusion Method ◽  
Disk Diffusion Test ◽  
Intermediate Resistance

In a context of worldwide emergence of resistance amongStreptococcus pneumoniae strains, early detection of strains with decreased susceptibility to β-lactam antibiotics is important for clinicians. If the 1-μg oxacillin disk diffusion test is used as described by the National Committee for Clinical Laboratory Standards, no interpretation is available for strains showing zone sizes of ≤19 mm, and there is presently no disk diffusion test available for screening cephalosporin resistance. The zones obtained by the diffusion method by using the 1-μg oxacillin disk were compared with penicillin MICs for 1,116 clinical strains and with ceftriaxone MICs for 695 of these strains. Among the 342 strains with growth up to the 1-μg oxacillin disk margin, none were susceptible (MIC, ≤0.06 μg/ml), 62 had intermediate resistance (MIC, 0.12 to 1.0 μg/ml), and 280 were resistant (MIC, ≥2.0 μg/ml) to penicillin. For ceftriaxone, among 98 strains with no zone of inhibition in response to oxacillin, 68 had intermediate resistance (MIC, 1.0 μg/ml), and 22 were resistant (MIC, ≥2.0 μg/ml). To optimize the use of the disk diffusion method, we propose that the absence of a zone of inhibition around the 1-μg oxacillin disk be regarded as an indicator of nonsusceptibility to penicillin and ceftriaxone and recommend that such strains be reported as nonsusceptible to these antimicrobial agents, pending the results of a MIC quantitation method.

scholarly journals Increasing Resistance and Changes in Distribution of Serotypes of Streptococcus agalactiae in Poland

Pathogens ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 526
Author(s):  
Dorota Kaminska ◽  
Magdalena Ratajczak ◽  
Anna Szumała-Kąkol ◽  
Jolanta Dlugaszewska ◽  
Dorota M. Nowak-Malczewska ◽  
...  
Keyword(s):  
Virulence Factors ◽  
Antimicrobial Susceptibility ◽  
Streptococcus Agalactiae ◽  
Penicillin G ◽  
Diffusion Method ◽  
Virulence Determinants ◽  
Group B Streptococci ◽  
Disk Diffusion Method ◽  
Microtiter Plate Assay ◽  
Genes Encoding

Streptococcus agalactiae is responsible for serious infections in newborn babies, pregnant women, and other patients. The aim of this study was to evaluate antimicrobial susceptibility, serotype distribution, and virulence determinants of the S. agalactiae isolates derived from clinical specimens considering the global increase of both antibiotic resistance and virulence. A total of 165 isolates were identified and serotyped by PCR techniques. Antimicrobial susceptibility was assessed by disk diffusion method, gradient diffusion method and VITEK® System. Virulence associated genes were investigated by PCR; ability to form biofilm was assessed using a microtiter plate assay. The highest observed MIC value for penicillin G was 0.12 µg/mL, seen in 8.5% of isolates. Resistance to erythromycin and clindamycin were found in 30.38% and 24.8% of the strains, respectively. The serotype III (32.73%), V (25.45%), and Ia (18.18%) were found as the most frequently represented. Previously unidentified strains in Poland, belonging to serotypes VI (three strains) and VII (one strain) were recognized. The presence of genes encoding various virulence factors as well as diverse ability to form biofilm were found. In conclusion, macrolide-resistance and decreased susceptibility to penicillin G were revealed signifying the increasing resistance among group B streptococci. Moreover, the presence of genes encoding various virulence factors and the ability to form biofilm were confirmed indicating their role in the pathomechanisms of the evaluated GBS infections.

scholarly journals Contamination and Antimicrobial Susceptibility Testing of Staphylococcus aureus Isolated from Pork in Fresh Markets, Nongchok District, Thailand

2021 ◽  
Vol 2021 ◽  
pp. 1-3
Author(s):  
Doungjit Kanungpean ◽  
Shinji Takai ◽  
Tsutomu Kakuda
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Susceptibility ◽  
Susceptibility Testing ◽  
Severe Infection ◽  
Antimicrobial Susceptibility Testing ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
Meat Markets ◽  
Pork Samples

We surveyed Staphylococcus aureus contamination in 110 pork samples from 12 fresh meat markets in Nongchok district, Bangkok, Thailand, and performed antimicrobial susceptibility testing with the disk diffusion method. The prevalence of S. aureus was 28.18%, and 52 strains were isolated. Antimicrobial susceptibility testing using the disk diffusion method revealed that 80.77% of the isolates were resistant to tetracycline and 76.92% to ampicillin. All strains were 100% susceptible to cloxacillin, cefoxitin, gentamicin, and cefazolin. The high percentage of antibiotic resistance to tetracycline and ampicillin was attributed to their use in treating infections in farmed animals and their addition to animal food for disease prevention. Interestingly, the present study revealed the intermediate resistance of S. aureus (13.46% of S. aureus-positive pork samples) to vancomycin which is a common medicine for treating severe infection in humans, suggesting that the trend of resistance might increase and becoming a serious problem of public health for both humans and animals.

Sign in / Sign up

Export Citation Format

Share Document