scholarly journals Listeriosis Cases and Genetic Diversity of Their L. monocytogenes Isolates in China, 2008–2019

2021 ◽  
Vol 11 ◽  
Author(s):  
Binghuai Lu ◽  
Junwen Yang ◽  
Chunyan Gao ◽  
Dong Li ◽  
Yanchao Cui ◽  
...  
Keyword(s):  
Fetal Loss ◽  
Genotypic Diversity ◽  
Fetal Membrane ◽  
Neonatal Infections ◽  
Microdilution Method ◽  
Food Borne ◽  
Broth Microdilution Method ◽  
High Prevalence ◽  
Nationwide Surveillance ◽  
Sequence Types

Listeriosis, caused by Listeria monocytogenes, is a severe food-borne infection. The nationwide surveillance in China concerning listeriosis is urgently needed. In the present study, 144 L. monocytogenes isolates were collected from the samples of blood, cerebrospinal fluid (CSF), and fetal membrane/placenta in China for 12 years from 2008 to 2019. We summarized these listeriosis patients’ demographical and clinical features and outcomes. The susceptibility profile for 12 antibiotics was also determined by the broth microdilution method. Multilocus sequence typing (MLST) and serogroups of these listeria isolates were analyzed to designate epidemiological types. We enrolled 144 cases from 29 healthcare centers, including 96 maternal-neonatal infections, 33 cases of bacteremia, 13 cases of neurolisteriosis, and two cutaneous listeriosis. There were 31 (59.6%) fetal loss in 52 pregnant women and four (9.8%) neonatal death in 41 newborns. Among the 48 nonmaternal-neonatal cases, 12.5% (6/48) died, 41.7% (20/48) were female, and 64.6% (31/48) occurred in those with significant comorbidities. By MLST, the strains were distinguished into 23 individual sequence types (STs). The most prevalent ST was ST87 (49 isolates, 34.0%), followed by ST1 (18, 12.5%), ST8 (10, 6.9%), ST619 (9, 6.3%), ST7 (7, 4.9%) and ST3 (7, 4.9%). Furthermore, all L. monocytogenes isolates were uniformly susceptible to penicillin, ampicillin, and meropenem. In summary, our study highlights a high genotypic diversity of L. monocytogenes strains causing clinical listeriosis in China. Furthermore, a high prevalence of ST87 and ST1 in the listeriosis should be noted.

scholarly journals High Prevalence of Azole-Resistant Aspergillus fumigatus in Adults with Cystic Fibrosis Exposed to Itraconazole

2011 ◽  
Vol 56 (2) ◽  
pp. 869-874 ◽  
Author(s):  
Pierre-Régis Burgel ◽  
Marie-Thérèse Baixench ◽  
Michaël Amsellem ◽  
Etienne Audureau ◽  
Jeanne Chapron ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Aspergillus Fumigatus ◽  
Allergic Bronchopulmonary Aspergillosis ◽  
Previous Treatment ◽  
University Hospital ◽  
Clinical Implications ◽  
Content Type ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
High Prevalence

ABSTRACTAspergillus fumigatusis the most frequent fungus found in the sputum of cystic fibrosis (CF) subjects. Itraconazole is prescribed for allergic bronchopulmonary aspergillosis (ABPA) orAspergillusbronchitis in CF subjects. We hypothesized thatA. fumigatusisolates in the sputum of CF subjects with previous exposure to itraconazole was associated with higher prevalence of azole resistance. From June 2010 to April 2011, sputum samples from adult CF subjects at Cochin University Hospital (France) were examined systematically for the detection ofA. fumigatus. MICs ofA. fumigatusisolates against azoles were screened using Etest, and reduced susceptibility to azoles was confirmed using the CLSI broth microdilution method.A. fumigatuswas isolated from the sputum of 131/249 (52.6%) adult CF subjects, and 47/131 (35.9%) subjects had received previous treatment with itraconazole. ReducedA. fumigatussusceptibility to itraconazole (MIC, ≥2 mg/liter) was confirmed in 6/131 (4.6%) subjects. All 6 isolates also had reduced susceptibility to posaconazole (MIC, ≥0.5 mg/liter), and 3/6 isolates had reduced susceptibility to voriconazole (MIC, ≥2 mg/liter). Mutations in thecyp51Agene were detected at positions previously implicated to cause resistance in 5 isolates. Azole-resistantA. fumigatusisolates were found in 5/25 (20%) subjects exposed to itraconazole within the previous 3 years. High rates of azole-resistantA. fumigatusisolates were present in adult CF subjects and were associated with recent itraconazole exposure. Although the clinical implications of these findings will require further studies, the cautious use of itraconazole in adult CF subjects can be recommended.

scholarly journals Cheese-related listeriosis outbreak, Portugal, March 2009 to February 2012

2015 ◽  
Vol 20 (17) ◽  
Author(s):  
R Magalhães ◽  
G Almeida ◽  
V Ferreira ◽  
I Santos ◽  
J Silva ◽  
...  
Keyword(s):  
Surveillance System ◽  
Fetal Loss ◽  
Case Fatality ◽  
Pulsed Field Gel Electrophoresis ◽  
Processing Plant ◽  
Neonatal Infections ◽  
Surveillance Programme ◽  
Source Of Infection ◽  
Food Borne ◽  
The Mean

In Portugal, listeriosis has been notifiable since April 2014, but there is no active surveillance programme for the disease. A retrospective study involving 25 national hospitals led to the detection of an outbreak that occurred between March 2009 and February 2012. The amount of time between the start of the outbreak and its detection was 16 months. Of the 30 cases of listeriosis reported, 27 were in the Lisbon and Vale do Tejo region. Two cases were maternal/neonatal infections and one resulted in fetal loss. The mean age of the non-maternal/neonatal cases was 59 years (standard deviation: 17); 13 cases were more than 65 years-old. The case fatality rate was 36.7%. All cases were caused by molecular serogroup IVb isolates indistinguishable by pulsed-field gel electrophoresis and ribotype profiles. Collaborative investigations with the national health and food safety authorities identified cheese as the probable source of infection, traced to a processing plant. The magnitude of this outbreak, the first reported food-borne listeriosis outbreak in Portugal, highlights the importance of having an effective listeriosis surveillance system in place for early detection and resolution of outbreaks, as well as the need for a process for the prompt submission of Listeria monocytogenes isolates for routine laboratory typing.

scholarly journals Punicalagin Inhibits Salmonella Virulence Factors and Has Anti-Quorum-Sensing Potential

2014 ◽  
Vol 80 (19) ◽  
pp. 6204-6211 ◽  
Author(s):  
Guanghui Li ◽  
Chunhong Yan ◽  
Yunfeng Xu ◽  
Yuqing Feng ◽  
Qian Wu ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Virulence Factors ◽  
Rt Pcr ◽  
Swarming Motility ◽  
Content Type ◽  
Microdilution Method ◽  
Food Borne ◽  
Broth Microdilution Method ◽  
Salmonella Virulence ◽  
Colonic Cells

ABSTRACTPunicalagin, an essential component of pomegranate rind, has been demonstrated to possess antimicrobial activity against several food-borne pathogens, but its activity on the virulence of pathogens and its anti-quorum-sensing (anti-QS) potential have been rarely reported. This study investigated the efficacy of subinhibitory concentrations of punicalagin onSalmonellavirulence factors and QS systems. A broth microdilution method was used to determine the MICs of punicalagin for 10Salmonellastrains. Motility assay and quantitative reverse transcription (RT)-PCR were performed to evaluate the effects of punicalagin on the virulence attributes and QS-related genes ofSalmonella. The MICs of punicalagin for severalSalmonellastrains ranged from 250 to 1,000 μg/ml. Motility assays showed that punicalagin, at 1/16× MIC and 1/32× MIC, significantly decreased bacterial swimming and swarming motility, which corresponded to downregulation of the motility-related genes (fliA,fliY,fljB,flhC, andfimD) in RT-PCR assays. RT-PCR also revealed that punicalagin downregulated the expression of most of the selected genes involved inSalmonellavirulence. Moreover, a QS inhibition assay indicated that punicalagin dose dependently inhibited the production of violacein byChromobacterium violaceumand repressed the expression of QS-related genes (sdiAandsrgE) inSalmonella. In addition, punicalagin significantly reducedSalmonellainvasion of colonic cells (P< 0.01) with no impact on adhesion. These findings suggest that punicalagin has the potential to be developed as an alternative or supplemental agent for prevention ofSalmonellainfection.

scholarly journals Co-occurrence of Carbapenemase-encoding Genes Among Klebsiella pneumoniae Clinical Isolates: Positive Relationship of bla NDM and bla SIM with Imipenem Resistance

2021 ◽  
Vol 14 (2) ◽  
Author(s):  
Maryam Galehdar ◽  
Maryam Ghane ◽  
Laleh Babaeekhou
Keyword(s):  
Klebsiella Pneumoniae ◽  
Multilocus Sequence Typing ◽  
Positive Relationship ◽  
Clinical Isolates ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
Significant Public Health ◽  
Overall Resistance ◽  
Encoding Genes ◽  
Sequence Types

Background: Carbapenem-resistant Klebsiella pneumoniae (CR-KP), known as a significant public health threat, is the most common causative agent of nosocomial and community-acquired infections. Objectives: This study aimed to evaluate resistance to carbapenems and determine the prevalence of carbapenemase genes and multilocus sequence typing (MLST) of K. pneumoniae clinical isolates. Methods: One-hundred K. pneumoniae isolates were evaluated. The minimum inhibitory concentrations (MIC) of imipenem and meropenem were assessed by the broth microdilution method. Multiplex-polymerase chain reaction (PCR) was applied to detect 11 carbapenemase-encoding genes belonging to different classes. The alleles and sequence types (ST) of three isolates were identified by MLST. Results: The MIC of carbapenems for the isolates ranged from 0.062 to 32 µg/mL. Overall, resistance rates to imipenem and meropenem were reported 11% and 34%, respectively. The bla IMP gene was the most abundant (78.4%), followed by bla OXA-48 (48.6%), bla GIM (27%), bla KPC (27%), bla SIM (21.6%), bla BIC (6.6%), bla NDM (16.2%), bla AIM (16.2%), bla VIM (16.2%), bla DIM (8.1%), and bla SPM (8.1%). The co-existence of carbapenemase genes was observed in 81.8% of the isolates. A positive relationship was found between the presence of bla NDM and bla SIM and resistance to imipenem. Multilocus sequence typing results showed three different sequence types, including ST14, ST5188, and ST1861. Conclusions: This study revealed a high prevalence of CR-KP isolates that suggests a high risk of horizontal gene transfer and potential to spread resistance among other strains. Since STs are reported for the first time in Iran, they can be considered as emerging strains.

scholarly journals In Vitro Activity of Dalbavancin against Refractory Multidrug-Resistant (MDR) Staphylococcus aureus Isolates

Antibiotics ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 865
Author(s):  
Dafne Bongiorno ◽  
Lorenzo Mattia Lazzaro ◽  
Stefania Stefani ◽  
Floriana Campanile
Keyword(s):  
Staphylococcus Aureus ◽  
Bactericidal Activity ◽  
Reference Strain ◽  
Multidrug Resistant ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
High Prevalence ◽  
Time Kill ◽  
Reference Strains

The high prevalence of methicillin-resistant Staphylococcus aureus (MRSA) infections, always treated with vancomycin and daptomycin, has led to the emergence of vancomycin-intermediate (VISA), heteroresistant vancomycin-intermediate (hVISA) and daptomycin non-susceptible (DNS) S. aureus. Even if glycopeptides and daptomycin remain the keystone for treatment of resistant S. aureus, the need for alternative therapies that target MRSA has now become imperative. The in vitro antibacterial and bactericidal activity of dalbavancin was evaluated against clinically relevant S. aureus showing raised antibiotic resistance levels, from methicillin-susceptible to Multidrug-Resistant (MDR) MRSA, including hVISA, DNS and rifampicin-resistant (RIF-R) strains. A total of 124 S. aureus strains were tested for dalbavancin susceptibility, by the broth microdilution method. Two VISA and 2 hVISA reference strains, as well as a vancomycin-resistant (VRSA) reference strain and a methicillin-susceptible Staphylococcus aureus (MSSA) reference strain, were included as controls. Time–kill curves were assayed to assess bactericidal activity. Dalbavancin demonstrated excellent in vitro antibacterial and bactericidal activity against all S. aureus resistance classes, including hVISA and DNS isolates. The RIF-R strains showed the highest percentage of isolates with non-susceptibility, reflecting the correlation between rpoB mutations and VISA/hVISA emergence. Our observations suggest that dalbavancin can be considered as an effective alternative for the management of severe MRSA infections also sustained by refractory phenotypes.

scholarly journals Genetic diversity of vancomycinresistant Enterococcus faecium isolated from blood culture in patients with hematological malignancies

2021 ◽  
Vol 23 (3) ◽  
pp. 305-313
Author(s):  
Svetlana A. Khrulnova ◽  
Galina A. Klyasova ◽  
A.V. Fedorova ◽  
I.N. Frolova ◽  
B.V. Biderman
Keyword(s):  
Genetic Diversity ◽  
High Risk ◽  
Blood Culture ◽  
Enterococcus Faecium ◽  
Hematological Malignancies ◽  
Clonal Complex ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
Polymerase Chain ◽  
Sequence Types

Objective. To study the genetic diversity of vancomycin-resistant Enterococcus faecium (VR-E. faecium) isolated from the blood culture in patients with hematological malignancies by multilocus sequence typing (MLST). Materials and Methods. VR-E. faecium isolated from the blood culture in hematological patients in 6 hospitals of 4 Russian cities (2003–2019) were evaluated. Susceptibility to vancomycin was tested by the broth microdilution method (CLSI, 2018). Vancomycin-resistance genes (vanA, vanB) were identified by polymerase chain reaction. Genotyping of VR-E. faecium was performed by MLST. Results. A total of 83 VR-E. faecium were examined. The vanA genes were detected in 71.1% (n = 59) VR-E. faecium, vanB genes – in 28.9% (n = 24). A total of 22 sequence types (STs) belonging to epidemic clonal complex CC17 were detected. The dominant sequence types were ST17 (19.3%), ST78 (18.1%), ST80 (16.9%), and comprised 54.3% VR-E. faecium. Other sequence types included 1 to 4 strains. VR-E. faecium carrying vanA, in comparison with VR-E. faecium vanB, significantly more often belonged to ST78 (23.7% vs. 4.2%, p = 0.0559, respectively) and ST80 (23.7% versus 0%, p = 0.0079, respectively) and less frequently to ST17 (6,8% versus 50%, р < 0.0001). Circulation of 9 STs including «high-risk» clones ST17 and ST78 was detected during two study periods (2003–2011 and 2012–2019). Conclusions. This study showed a genetic diversity of VR-E. faecium that was represented by 22 STs. All VR-E. faecium belonged to epidemic clonal complex CC17 and comprised «high-risk» clones ST17, ST78 and less common STs.

A 10 year surveillance for antimicrobial susceptibility of Escherichia coli and Klebsiella pneumoniae in community- and hospital-associated intra-abdominal infections in China

2013 ◽  
Vol 62 (9) ◽  
pp. 1343-1349 ◽  
Author(s):  
Qiwen Yang ◽  
Hui Zhang ◽  
Yao Wang ◽  
Yingchun Xu ◽  
Minjun Chen ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Klebsiella Pneumoniae ◽  
Fourth Generation ◽  
Extended Spectrum Beta Lactamase ◽  
E Coli ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
High Prevalence ◽  
Positive Rate ◽  
Abdominal Infections

The objective of this study was to investigate the susceptibility of hospital-associated (HA) and community-associated (CA) Escherichia coli and Klebsiella pneumoniae isolated from patients with intra-abdominal infections (IAIs) in China. From 2002 to 2011, the minimum inhibitory concentrations (MICs) of 12 antibiotics against 3074 E. coli and 1025 K. pneumoniae from 23 centres located in 16 cities were determined by the broth microdilution method. During the 10 year study period, ertapenem, imipenem, amikacin and piperacillin-tazobactam retained high and stable activity against E. coli and K. pneumoniae isolates regardless of whether their source was HA or CA and regardless of their extended-spectrum beta-lactamase (ESBL) production. However, the susceptibility of E. coli to cephalosporins and ampicillin-sulbactam decreased dramatically during the 10 years, especially for the CA isolates. Fluoroquinolones showed low activity against E. coli. During the whole study period, the ESBL rates for E. coli isolates from IAIs increased from 36.1 % in 2002–2003 to 68.1 % in 2010–2011 (P<0.001). Correspondingly, the ESBL rates in HA isolates increased from 52.2 % in 2002–2003 to 70.0 % in 2010–2011 (P = 0.001), and in CA isolates from 19.1 % in 2002–2003 to 61.6 % in 2010–2011 (P<0.001). The ESBL-positive rate in K. pneumoniae remained between 30.1 and 39.3 % of the total isolates with no significant change during the 10 years. In conclusion, carbapenems retained the highest susceptibility rates against HA and CA E. coli and K. pneumoniae. High prevalence of ESBL in HA E. coli and fast-growing resistance in CA E. coli severely limit the empirical use of the third- and fourth-generation cephalosporins in the therapy of IAIs.

scholarly journals Chemical Composition andIn VitroAntibacterial Activity ofMentha spicataEssential Oil against Common Food-Borne Pathogenic Bacteria

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Yasser Shahbazi
Keyword(s):  
Antibacterial Activity ◽  
Chemical Composition ◽  
Essential Oil ◽  
Pathogenic Bacteria ◽  
Inhibition Zone ◽  
Mentha Spicata ◽  
Common Food ◽  
Microdilution Method ◽  
Food Borne ◽  
Broth Microdilution Method

The aim of the present study was to investigate chemical composition and antibacterial activity of essential oil from the leaf ofMentha spicataplant against common food-borne pathogenic bacteria (Staphylococcus aureus, Bacillus subtilis, Bacillus cereus, Listeria monocytogenes, Salmonella typhimurium, andEscherichia coliO157:H7). Chemical composition of the essential oil was identified by gas chromatography coupled with mass spectrometer detector (GC-MS). The antibacterial activity of the essential oil was evaluated by broth microdilution method and agar disk diffusion assay. According to the result of GC-MS analysis, 18 components were identified, accounting for 99.89% of the whole essential oil. The main components were carvone (78.76%), limonene (11.50%),β-bourbonene (11.23%),cis-dihydrocarveol (1.43%),trans-caryophyllene (1.04%), menthone (1.01%), menthol (1%), and terpinen-4-ol (0.99). The essential oil exhibited moderate level of antibacterial activity against all test microorganisms. In general, Gram-positive bacteria were more susceptible toM. spicataessential oil than Gram-negative bacteria.L. monocytogeneswas the most sensitive of the microorganisms to the antibacterial activity ofM. spicataessential oil (inhibition zone = 22 mm and MIC and MBC = 2.5 µL/mL). Based on our results, the essential oil ofM. spicataplant collected from Kermanshah province, west of Iran, has a potential to be applied as antibacterial agent.

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