scholarly journals Serotype Distribution, Antimicrobial Susceptibility, Multilocus Sequencing Type and Virulence of Invasive Streptococcus pneumoniae in China: A Six-Year Multicenter Study

2022 ◽  
Vol 12 ◽  
Author(s):  
Menglan Zhou ◽  
Ziran Wang ◽  
Li Zhang ◽  
Timothy Kudinha ◽  
Haoran An ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Multicenter Study ◽  
Antimicrobial Susceptibility ◽  
Capsular Polysaccharide ◽  
Microdilution Method ◽  
Strain Collection ◽  
Broth Microdilution Method ◽  
Quellung Reaction ◽  
Resistance Rates ◽  
Virulence Diversity

Background:Streptococcus pneumoniae is an important human pathogen that can cause severe invasive pneumococcal diseases (IPDs). The aim of this multicenter study was to investigate the serotype and sequence type (ST) distribution, antimicrobial susceptibility, and virulence of S. pneumoniae strains causing IPD in China.Methods: A total of 300 invasive S. pneumoniae isolates were included in this study. The serotype, ST, and antimicrobial susceptibility of the strains, were determined by the Quellung reaction, multi-locus sequence typing (MLST) and broth microdilution method, respectively. The virulence level of the strains in the most prevalent serotypes was evaluated by a mouse sepsis model, and the expression level of well-known virulence genes was measured by RT-PCR.Results: The most common serotypes in this study were 23F, 19A, 19F, 3, and 14. The serotype coverages of PCV7, PCV10, PCV13, and PPV23 vaccines on the strain collection were 42.3, 45.3, 73.3 and 79.3%, respectively. The most common STs were ST320, ST81, ST271, ST876, and ST3173. All strains were susceptible to ertapenem, levofloxacin, moxifloxacin, linezolid, and vancomycin, but a very high proportion (>95%) was resistant to macrolides and clindamycin. Based on the oral, meningitis and non-meningitis breakpoints, penicillin non-susceptible Streptococcus pneumoniae (PNSP) accounted for 67.7, 67.7 and 4.3% of the isolates, respectively. Serotype 3 strains were characterized by high virulence levels and low antimicrobial-resistance rates, while strains of serotypes 23F, 19F, 19A, and 14, exhibited low virulence and high resistance rates to antibiotics. Capsular polysaccharide and non-capsular virulence factors were collectively responsible for the virulence diversity of S. pneumoniae strains.Conclusion: Our study provides a comprehensive insight into the epidemiology and virulence diversity of S. pneumoniae strains causing IPD in China.

Comparison of antimicrobial resistance patterns in Streptococcus pneumoniae from respiratory and blood cultures in Canadian hospitals from 2007–16

2019 ◽  
Vol 74 (Supplement_4) ◽  
pp. iv39-iv47 ◽  
Author(s):  
Alyssa R Golden ◽  
Melanie R Baxter ◽  
Ross J Davidson ◽  
Irene Martin ◽  
Walter Demczuk ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Antimicrobial Susceptibility ◽  
Invasive Disease ◽  
Non Invasive ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
Resistance Patterns ◽  
Specific Factors ◽  
Susceptibility Patterns ◽  
Respiratory Specimens

Abstract Objectives To compare the epidemiology and antimicrobial susceptibility patterns of Streptococcus pneumoniae collected from respiratory and blood culture samples in Canada between 2007 and 2016. Methods S. pneumoniae strains were obtained from Canadian hospitals as part of the ongoing national surveillance study, CANWARD. Isolates were serotyped using the Quellung method. Antimicrobial susceptibility testing was performed using the CLSI broth microdilution method. MDR and XDR were defined as resistance to three or more and five or more classes of antimicrobials, respectively. Results Of the 2581 S. pneumoniae isolates collected, 1685 (65.3%) and 896 (34.7%) were obtained from respiratory and blood samples, respectively. Respiratory isolates demonstrated lower rates of antimicrobial susceptibility than blood isolates to penicillin, ceftriaxone, clarithromycin, clindamycin, doxycycline and trimethoprim/sulfamethoxazole (P ≤ 0.03). From 2007 to 2016, invasive isolates demonstrated trends towards increasing penicillin susceptibility and decreasing clarithromycin susceptibility. MDR was significantly higher in respiratory S. pneumoniae compared with blood (9.1% versus 4.5%, P < 0.0001). Serotypes 11A, 16F, 19F, 23A/B/F, 34, 35B and non-typeable strains were more commonly isolated from respiratory specimens, while 4, 5, 7F, 8, 12F, 14 and 19A were more commonly invasive serotypes. Numerous serotypes, including 3 and 22F, were isolated frequently from both specimen sources. Conclusions S. pneumoniae from respiratory samples demonstrated lower antimicrobial susceptibilities and higher MDR in a greater diversity of serotypes than isolates obtained from blood. Many serotypes were associated with one specific specimen source, while others were associated with both; genetic characterization is necessary to elucidate the specific factors influencing the ability of these serotypes to commonly cause both invasive and non-invasive disease.

scholarly journals Invasive isolates of Streptococcus pneumoniae in Serbia: Antimicrobial susceptibility and serotypes

2013 ◽  
Vol 141 (1-2) ◽  
pp. 48-53 ◽  
Author(s):  
Ina Gajic ◽  
Vera Mijac ◽  
Lazar Ranin ◽  
Dragana Andjelkovic ◽  
Miroslava Radicevic ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Invasive Pneumococcal Disease ◽  
Antimicrobial Susceptibility ◽  
Pneumococcal Disease ◽  
Medical Problem ◽  
Resistance Rate ◽  
Reference Laboratory ◽  
Susceptibility Pattern ◽  
Antimicrobial Susceptibility Pattern ◽  
Resistance Rates

Introduction. Streptococcus pneumoniae is one of the leading causes of bacterial meningitis and sepsis. Invasive pneumococcal disease is a significant medical problem worldwide, particularly in children, due to a huge increase of pneumococcal resistance to antibiotics. Objective. The aim of the study was to investigate the antimicrobial susceptibility pattern of invasive pneumococcal isolates, as well as to determine whether decreased S. pneumoniae susceptibility to antibiotics was related to a particular serotype. Methods. Antimicrobial susceptibility to 19 antibiotics was determined in 58 invasive pneumococcal strains that were collected from seven regional centers during the period July 2009 to February 2011 in the National Reference Laboratory for streptococci and pneumococci. Results. The overall nonsusceptibility rate to penicillin was detected in 34% of pneumococcal isolates and to erythromycin in 36%. Higher resistance rates were observed among children than among adults. Penicillin resistance rate was 65% in children versus 22% in adults, while erythromycin nonsusceptibility rate was 47% in children versus 32% in adults. Co-resistance to penicillin and erythromycin was detected in 21% strains, mostly isolated from children. Multiresistance was found in one third of isolates. All strains were susceptible to vancomycin, linezolid, fluoroquinolones, telithromycin and rifampicin, while 23 (40%) isolates were susceptible to all tested antibiotics. The most common resistant serotypes were 19F and 14. Conclusion. The study has revealed that penicillin and macrolide resistance among invasive pneumococcal isolates is very high in Serbia. This emphasizes the need for continuous monitoring for invasive pneumococcal disease to document the serotype distribution and antimicrobial susceptibility pattern.

Antimicrobial Resistance in Campylobacter jejuni from Broilers and Broiler House Environments in Norway

2007 ◽  
Vol 70 (3) ◽  
pp. 736-738 ◽  
Author(s):  
M. NORSTRÖM ◽  
G. JOHNSEN ◽  
M. HOFSHAGEN ◽  
H. THARALDSEN ◽  
H. KRUSE
Keyword(s):  
Antimicrobial Resistance ◽  
Campylobacter Jejuni ◽  
Antimicrobial Susceptibility ◽  
Antimicrobial Agents ◽  
Monitoring Program ◽  
Outdoor Environment ◽  
Susceptibility Data ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
Broiler House

Antimicrobial susceptibility in Campylobacter jejuni collected from the environment outside four broiler houses (n = 63) and from the environment inside these broiler houses (including broiler droppings) (n = 36) from May to September 2004 was studied and compared with isolates from Norwegian broilers analyzed within the frame of the Norwegian monitoring program of antimicrobial resistance in feed, food, and animals (NORM-VET) in 2004 (n = 75). The MICs of oxytetracycline, ampicillin, erythromycin, gentamicin, enrofloxacin, and nalidixic acid were obtained by the broth microdilution method VetMIC. The present study, which to our knowledge is the first Norwegian study on the occurrence of antimicrobial resistance in Campylobacter spp. from the environment of broiler houses, revealed a very low occurrence of antimicrobial resistance in C. jejuni from the broilers and broiler house environments studied. All isolates originating from the four broiler houses studied were susceptible to all the antimicrobial agents tested, except for one isolate from the outdoor environment (courtyard soil), which was resistant to oxytetracycline (MIC, 8 mg/liter). For the isolates from broilers (NORM-VET), low prevalences of resistance to oxytetracycline (1.3%) and ampicillin (4%) were observed. No quinolone resistance was observed. The results for the broiler isolates are in agreement with the earlier findings of a very low prevalence of resistance in Campylobacter from broilers in Norway, which reflects the low usage of antimicrobials in Norwegian broiler production. Furthermore, the present data are in accordance with antimicrobial susceptibility data for C. jejuni from domestically acquired human cases.

scholarly journals Antimicrobial susceptibility of Pasteurella multocida isolated from sheep and pigs in Spain – Short communication

2019 ◽  
Vol 67 (4) ◽  
pp. 489-498
Author(s):  
Dolores Cid ◽  
José Francisco Fernández-Garayzábal ◽  
Chris Pinto ◽  
Lucas Domínguez ◽  
Ana Isabel Vela
Keyword(s):  
High Resistance ◽  
Antimicrobial Susceptibility ◽  
Pasteurella Multocida ◽  
Antimicrobial Agents ◽  
Empirical Therapy ◽  
Microdilution Method ◽  
Low Levels ◽  
Resistance Rates ◽  
Farming Industry ◽  
Susceptibility Patterns

Pasteurella multocida is responsible for economically important diseases in sheep and pigs. Antimicrobial susceptibility studies are essential for initiating rational and effective empirical therapy of P. multocida infections. In this study we investigated the antimicrobial susceptibility to 18 antimicrobial agents of 156 clinical isolates of P. multocida from sheep (n = 87) and pigs (n = 69) using the microdilution method. Both sheep and pig isolates exhibited low levels of resistance (≤ 15%) to ceftiofur, gentamicin, neomycin, spectinomycin, chlortetracycline, tulathromycin, florfenicol, danofloxacin, and enrofloxacin and trimethoprim/sulphamethoxazole, high resistance rates (> 15% up to 50%) to oxytetracycline, tilmicosin, and tiamulin, and very high resistance rates (> 50%) to tylosin tartrate, clindamycin, and sulphadimethoxine. However, sheep isolates exhibited significantly lower percentages of resistance and lower MIC90 values (P < 0.05) than pig isolates for most of the antimicrobials tested. In addition, sheep isolates exhibited also significantly lower phenotypic antimicrobial resistance diversity (8 resistotypes vs. 30 resistotypes). LAC-LIN-SUL-MAC was the resistotype most frequently detected in sheep (39.1%) and LIN-SUL-MAC in pig isolates (26.1%). The differences in susceptibility patterns could be influenced by the lower use of antimicrobials in the small ruminant industry compared with the pig farming industry.

scholarly journals Variation in erythromycin and clindamycin susceptibilities of Streptococcus pneumoniae by four test methods.

1997 ◽  
Vol 41 (1) ◽  
pp. 129-134 ◽  
Author(s):  
E L Fasola ◽  
S Bajaksouzian ◽  
P C Appelbaum ◽  
M R Jacobs
Keyword(s):  
Streptococcus Pneumoniae ◽  
Susceptibility Testing ◽  
Ambient Air ◽  
Test Methods ◽  
Disk Diffusion ◽  
Broth Microdilution ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
Agar Dilution ◽  
Resistant Strains

Susceptibilities of 124 strains of Streptococcus pneumoniae to erythromycin and clindamycin were determined by the National Committee for the Clinical Laboratory Standards (NCCLS) broth microdilution method, with incubation for 20 to 24 h in ambient air and with modifications of this method by incubation for up to 48 h in air and CO2. Strains were also tested by agar dilution, E-test, and disk diffusion; good correlation was obtained with these methods, with clear separation into bimodal populations of susceptible and resistant stains. The broth microdilution method, however, using incubation in air for 24 h (NCCLS method), misclassified 4 of 92 erythromycin-resistant strains (1 as susceptible and 3 as intermediate) and 25 of 58 clindamycin-resistant strains (all as susceptible). With the exception of one strain with clindamycin, susceptible and resistant strains were correctly classified by the microdilution method with incubation in CO2 for 24 h or in ambient air for 48 h. Disk diffusion, agar dilution, and E-test methods with incubation in 5% CO2 are therefore reliable methods for susceptibility testing of pneumococci against these agents. However, the NCCLS microdilution method, which specifies incubation for 20 to 24 h in ambient air, produced significant very major errors (43%) clindamycin. Modification of the microdilution method by incubation in 5% CO2 or by extension of incubation time in ambient air to 48 h corrected these errors. Disk diffusion, however, was shown to be a simple, convenient, and reliable method for susceptibility testing of pneumococci to erythromycin and clindamycin and is suggested as the method of choice for these agents.

scholarly journals Antimicrobial Susceptibility of 6685 Organisms Isolated from Canadian Hospitals: CANWARD 2007

2009 ◽  
Vol 20 (suppl a) ◽  
pp. 20A-30A
Author(s):  
George G Zhanel ◽  
Mel DeCorby ◽  
Kim A Nichol ◽  
Aleksandra Wierzbowski ◽  
Patricia J Baudry ◽  
...  
Keyword(s):  
Antimicrobial Susceptibility ◽  
Susceptibility Testing ◽  
Methicillin Resistant ◽  
E Coli ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
Testing Susceptibility ◽  
Polymyxin E ◽  
Vancomycin Resistant ◽  
Gram Positive Cocci

BACKGROUND: Antimicrobial resistance is a growing problem in North American hospitals as well as hospitals worldwide. OBJECTIVES: To assess the antimicrobial susceptibility patterns of commonly used agents against the 20 most common organisms isolated from Canadian hospitals. METHODS: In total, 7881 isolates were obtained between January 1, 2007, and December 31, 2007, from 12 hospitals across Canada as part of the Canadian Ward Surveillance Study (CANWARD 2007). Of these, 6685 isolates (20 most common organisms) obtained from bacteremic, urinary, respiratory and wound specimens underwent antimicrobial susceptibility testing. Susceptibility testing was assessed using the Clinical and Laboratory Standards Institute broth microdilution method. RESULTS: The most active (based upon minimum inhibitory concentration [MIC] data only) agents against methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant Staphylococcus epidermidis (MRSE) were dalbavancin, daptomycin, linezolid, telavancin, tigecycline and vancomycin, with MICs required to inhibit the growth of 90% of organisms (MIC90) of 0.06 μg/mL and 0.06 μg/mL, 0.25 μg/mL and 0.25 μg/mL, 4 μg/mL and 1 μg/mL, 0.25 μg/mL and 0.25 μg/mL, 0.5 μg/mL and 0.25 μg/mL, and 1 μg/mL and 2 μg/mL, respectively. The most active agents against vancomycin-resistant enterococci were daptomycin, linezolid and tigecycline with MIC90sof 2 μg/mL, 4 μg/mL and 0.12 μg/mL, respectively. The most active agents againstEscherichia coliwere amikacin, cefepime, ertapenem, meropenem, piperacillin-tazobactam and tigecycline with MIC90sof 4 μg/mL, 2 μg/mL, 0.06 μg/mL or less, 0.12 μg/mL or less, 4 μg/mL and 1 μg/mL, respectively. The most active agents against extendedspectrum beta-lactamase-producing E coli were ertapenem, meropenem and tigecycline with MIC90sof 0.12 μg/mL or less, 0.12 μg/mL or less and 1 μg/mL, respectively. The most active agents againstPseudomonas aeruginosawere amikacin, cefepime, meropenem and piperacillin-tazobactam with MIC90sof 32 μg/mL, 32 μg/mL, 8 μg/mL and 64 μg/mL, respectively. The most active agents againstStenotrophomonas maltophiliawere tigecycline and trimethoprimsulfamethoxazole and levofloxacin with MIC90sof 8 μg/mL, 8 μg/mL and 8 μg/mL, respectively. The most active agents againstAcinetobacter baumanniiwere amikacin, fluoroquinolones (eg, levofloxacin), meropenem, and tigecycline with MIC90sof 2 μg/mL or less, 1 μg/mL, 4 μg/mL and 2 μg/mL, respectively. CONCLUSIONS: The most active agents versus Gram-positive cocci from Canadian hospitals were vancomycin, linezolid, daptomycin, tigecycline, dalbavancin and telavancin. The most active agents versus Gram-negative bacilli from Canadian hospitals were amikacin, cefepime, ertapenem (notP aeruginosa), meropenem, piperacillintazobactam and tigecycline (notP aeruginosa). Colistin (polymyxin E) was very active againstP aeruginosaandA baumannii.

scholarly journals Decline and Rise of the Antimicrobial Susceptibility of Streptococcus pneumoniae Isolated from Middle Ear Fluid in Children: Influence of Changes in Circulating Serotypes

2012 ◽  
Vol 56 (7) ◽  
pp. 3989-3991 ◽  
Author(s):  
Emilio Pérez-Trallero ◽  
José M. Marimón ◽  
Marta Alonso ◽  
María Ercibengoa ◽  
José M. García-Arenzana
Keyword(s):  
Streptococcus Pneumoniae ◽  
Antimicrobial Resistance ◽  
Middle Ear ◽  
Antimicrobial Susceptibility ◽  
Multidrug Resistant ◽  
Northern Spain ◽  
Content Type ◽  
Middle Ear Fluid ◽  
Resistance Rates ◽  
Heptavalent Pneumococcal Conjugate Vaccine

ABSTRACTChanges in the antimicrobial susceptibility ofStreptococcus pneumoniaecausing otitis media were studied in 916 isolates from children <5 years old between 1999 and 2010 in a region of northern Spain. The rate of antimicrobial resistance decreased between the period before the introduction of the heptavalent pneumococcal conjugate vaccine (from 1999 to 2001) and the period from 2005 to 2007. However, in 2008 to 2010, resistance rates increased again due to the spread of serotype 19A, especially the multidrug-resistant ST320 and ST276 clones.

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