scholarly journals Detection of an Archaic Clone of Staphylococcus aureuswith Low-Level Resistance to Methicillin in a Pediatric Hospital in Portugal and in International Samples: Relics of a Formerly Widely Disseminated Strain?

1999 ◽  
Vol 37 (6) ◽  
pp. 1913-1920 ◽  
Author(s):  
Raquel Sá-Leão ◽  
Ilda Santos Sanches ◽  
Dora Dias ◽  
Isabel Peres ◽  
Rosa M. Barros ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
The United States ◽  
Multidrug Resistant ◽  
Type I ◽  
Pediatric Hospital ◽  
Low Level ◽  
Clonal Type ◽  
Mrsa Strains ◽  
High Level ◽  
Level Resistance

Close to half of the 878 methicillin-resistant Staphylococcus aureus (MRSA) strains recovered between 1992 and 1997 from the pediatric hospital in Lisbon were bacteria in which antibiotic resistance was limited to β-lactam antibiotics. The other half were multidrug resistant. The coexistence of MRSA with such unequal antibiotic resistance profiles prompted us to use molecular typing techniques for the characterization of the MRSA strains. Fifty-three strains chosen randomly were typed by a combination of genotypic methods. Over 90% of the MRSA strains belonged to two clones: the most frequent one, designated the “pediatric clone,” was reminiscent of historically “early” MRSA: most isolates of this clone were only resistant to β-lactam antimicrobials and remained susceptible to macrolides, quinolones, clindamycin, spectinomycin, and tetracycline. They showed heterogeneous and low-level resistance to methicillin (MIC, 1.5 to 6 μg/ml), carried the ClaI-mecApolymorph II, were free of the transposon Tn554, and showed macrorestriction pattern D (clonal type II::NH::D). The second major clone was the internationally spread and multiresistant “Iberian” MRSA with homogeneous and high-level resistance to methicillin (MIC, >200 μg/ml) and clonal type I::E::A. Surprisingly, the multidrug-resistant and highly epidemic Iberian MRSA did not replace the much less resistant pediatric clone during the 6 years of surveillance. The pediatric clone was also identified among contemporary MRSA isolates from Poland, Argentina, The United States, and Colombia, and the overwhelming majority of these were also associated with pediatric settings. We propose that the pediatric MRSA strain represents a formerly widely spread archaic clone which survived in some epidemiological settings with relatively limited antimicrobial pressure.

scholarly journals Ceftobiprole- and Ceftaroline-Resistant Methicillin-Resistant Staphylococcus aureus

2015 ◽  
Vol 59 (5) ◽  
pp. 2960-2963 ◽  
Author(s):  
Liana C. Chan ◽  
Li Basuino ◽  
Binh Diep ◽  
Stephanie Hamilton ◽  
Som S. Chatterjee ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Methicillin Resistant ◽  
Content Type ◽  
Low Level ◽  
Mrsa Strains ◽  
High Level ◽  
Level Resistance

ABSTRACTThe role ofmecAmutations in conferring resistance to ceftobiprole and ceftaroline, cephalosporins with anti-methicillin-resistantStaphylococcus aureus(MRSA) activity, was determined with MRSA strains COL and SF8300. The SF8300 ceftaroline-passaged mutant carried a singlemecAmutation, E447K (E-to-K change at position 447), and expressed low-level resistance. This mutation in COL conferred high-level resistance to ceftobiprole but only low-level resistance to ceftaroline. The COL ceftaroline-passaged mutant, which expressed high-level resistance to ceftobiprole and ceftaroline, had mutations inpbp2,pbp4, andgdpPbut notmecA.

scholarly journals Staphylococcus aureus Clinical Isolate with High-Level Methicillin Resistance with an lytH Mutation Caused by IS1182 Insertion

2007 ◽  
Vol 52 (2) ◽  
pp. 643-647 ◽  
Author(s):  
Takaji Fujimura ◽  
Kazuhisa Murakami
Keyword(s):  
Staphylococcus Aureus ◽  
Clinical Isolate ◽  
Methicillin Resistance ◽  
Clinical Isolates ◽  
Lytic Enzymes ◽  
Resistance Level ◽  
Low Level ◽  
Mrsa Strains ◽  
High Level ◽  
Level Resistance

ABSTRACT We previously reported that deficiency of the lytH gene, whose product is homologous to lytic enzymes, caused the elevation of methicillin resistance in Staphylococcus aureus strain SR17238, a strain of S. aureus with a low level of resistance to methicillin (low-level MRSA) (J. Bacteriol. 179:6294-6301, 1997). In this study, we demonstrated that deficiency of lytH caused the same phenomenon in four other clinical isolates of low-level MRSA, suggesting this deficiency to exist in clinical isolates. We therefore searched the region including lytH in 127 clinical isolates of MRSA by PCR and found one strain, SR17164 (methicillin MIC, 1,600 μg/ml), in which the lytH gene was inactivated by insertion sequence IS1182. lytH::IS1182 was replaced with intact lytH in this strain by integration and excision of the plasmid carrying the lytH region. Recombinants with intact lytH genes showed methicillin MICs of 800 μg/ml, twofold lower than those of the recombinants with lytH::IS1182 and the parent. In addition, S. aureus SR17164, which has a high level of methicillin resistance, had properties similar to those caused by lytH deficiency; that is, the resistance levels of strain SR17164 and lytH-deficient variants from strain SR17238 were not significantly affected by llm inactivation, which greatly lowered resistance levels in most other high-level MRSA strains. These findings suggest that lytH inactivation contributed, to some extent, to the resistance level of S. aureus SR17164. To the best of our knowledge, this strain is the first clinical isolate of MRSA for which the genetic base for high-level resistance has been clarified.

scholarly journals Emergence ofileS2-Carrying, Multidrug-Resistant Plasmids in Staphylococcus lugdunensis

2016 ◽  
Vol 60 (10) ◽  
pp. 6411-6414 ◽  
Author(s):  
Pak-Leung Ho ◽  
Melissa Chun-Jiao Liu ◽  
Kin-Hung Chow ◽  
Cindy Wing-Sze Tse ◽  
Wai-U Lo ◽  
...  
Keyword(s):  
Hong Kong ◽  
Multidrug Resistant ◽  
Staphylococcus Lugdunensis ◽  
Content Type ◽  
Low Level ◽  
Resistance Determinants ◽  
Mupirocin Resistance ◽  
High Level ◽  
Level Resistance

ABSTRACTOf 137Staphylococcus lugdunensisisolates collected from two nephrology centers in Hong Kong, 10 (7.3%) and 3 (2.2%) isolates had high-level and low-level mupirocin resistance, respectively. Isolates with high-level resistance contained the plasmid-mediatedileS2gene, while isolates with low-level resistance contained the mutation V588F within the chromosomalileSgene. All but one of theileS2-positive isolates belong to the predominating clone HKU1. Plasmids carrying theileS2gene were mosaic and also cocarry multiple other resistance determinants.

scholarly journals Candida auris and Carbapenemase-Producing Organism Prevalence in an Extended Stay Pediatric Hospital, Chicago, Illinois, 2019

2020 ◽  
Vol 41 (S1) ◽  
pp. s145-s146
Author(s):  
Kelly Walblay ◽  
Tristan McPherson ◽  
Elissa Roop ◽  
David Soglin ◽  
Ann Valley ◽  
...  
Keyword(s):  
The United States ◽  
Multidrug Resistant ◽  
Pediatric Hospital ◽  
Mechanical Ventilators ◽  
Candida Auris ◽  
Term Care ◽  
Healthcare Settings ◽  
High Acuity ◽  
Gastrostomy Tubes

Background:Candida auris and carbapenemase-producing organisms (CPO) are multidrug-resistant organisms that can colonize people for prolonged periods and can cause invasive infections and spread in healthcare settings, particularly in high-acuity long-term care facilities. Point-prevalence surveys (PPSs) conducted in long-term acute-care hospitals in the Chicago region identified median prevalence of colonization to be 31% for C. auris and 24% for CPO. Prevalence of C. auris colonization has not been described in pediatric populations in the United States, and limited data exist on CPO colonization in children outside intensive care units. The Chicago Department of Public Health (CDPH) conducted a PPS to assess C. auris and CPO colonization in a pediatric hospital serving high-acuity patients with extended lengths of stay (LOS). Methods: CDPH conducted a PPS in August 2019 in a pediatric hospital with extended LOS to screen for C. auris and CPO colonization. Medical devices (ie, gastrostomy tubes, tracheostomies, mechanical ventilators, and central venous catheters [CVC]) and LOS were documented. Screening specimens consisted of composite bilateral axillae and groin swabs for C. auris and rectal swabs for CPO testing. The Wisconsin State Laboratory of Hygiene tested all specimens. Real-time polymerase chain reaction (PCR) assays were used to detect C. auris DNA and carbapenemase genes: blaKPC, blaNDM, blaVIM, blaOXA-48, and blaIMP (Xpert Carba-R Assay, Cepheid, Sunnyvale, CA). All axillae and groin swabs were processed by PCR and culture to identify C. auris. For CPO, culture was only performed on PCR-positive specimens. Results: Of the 29 patients hospitalized, 26 (90%) had gastrostomy tubes, 24 (83%) had tracheostomies, 20 (69%) required mechanical ventilation, and 3 (10%) had CVCs. Also, 25 (86%) were screened for C. auris and CPO; 4 (14%) lacked parental consent and were not swabbed. Two rectal specimens were unsatisfactory, producing invalid CPO test results. Median LOS was 35 days (range, 1–300 days). No patients were positive for C. auris. From CPO screening, blaOXA-48 was detected in 1 patient sample, yielding a CPO prevalence of 3.4% (1 of 29). No organism was recovered from the blaOXA-48 positive specimen. Conclusions: This is the first documented screening of C. auris colonization in a pediatric hospital with extended LOS. Despite a high prevalence of C. auris and CPOs in adult healthcare settings of similar acuity in the region, C. auris was not identified and CPOs were rare at this pediatric facility. Additional evaluations in pediatric hospitals should be conducted to further understand C. auris and CPO prevalence in this population.Funding: NoneDisclosures: None

scholarly journals ArmA Methyltransferase in a Monophasic Salmonella enterica Isolate from Food

2011 ◽  
Vol 55 (11) ◽  
pp. 5262-5266 ◽  
Author(s):  
Sophie A. Granier ◽  
Laura Hidalgo ◽  
Alvaro San Millan ◽  
Jose Antonio Escudero ◽  
Belen Gutierrez ◽  
...  
Keyword(s):  
16S Rrna ◽  
Salmonella Enterica ◽  
Multidrug Resistant ◽  
Broad Host Range ◽  
En Bloc ◽  
Content Type ◽  
Route Of Transmission ◽  
Amoxicillin Clavulanate ◽  
High Level ◽  
Level Resistance

ABSTRACTThe 16S rRNA methyltransferase ArmA is a worldwide emerging determinant that confers high-level resistance to most clinically relevant aminoglycosides. We report here the identification and characterization of a multidrug-resistantSalmonella entericasubspecies I.4,12:i:− isolate recovered from chicken meat sampled in a supermarket on February 2009 in La Reunion, a French island in the Indian Ocean. Susceptibility testing showed an unusually high-level resistance to gentamicin, as well as to ampicillin, expanded-spectrum cephalosporins and amoxicillin-clavulanate. Molecular analysis of the 16S rRNA methyltransferases revealed presence of thearmAgene, together withblaTEM-1,blaCMY-2, andblaCTX-M-3. All of these genes could be transferreden blocthrough conjugation intoEscherichia coliat a frequency of 10−5CFU/donor. Replicon typing and S1 pulsed-field gel electrophoresis revealed that thearmAgene was borne on an ∼150-kb broad-host-range IncP plasmid, pB1010. To elucidate howarmAhad integrated in pB1010, a PCR mapping strategy was developed for Tn1548, the genetic platform forarmA.The gene was embedded in a Tn1548-like structure, albeit with a deletion of the macrolide resistance genes, and an IS26was inserted within themelgene. To our knowledge, this is the first report of ArmA methyltransferase in food, showing a novel route of transmission for this resistance determinant. Further surveillance in food-borne bacteria will be crucial to determine the role of food in the spread of 16S rRNA methyltransferase genes worldwide.

scholarly journals O05.4 Does high-level azithromycin resistance emerge from low-level resistance inneisseria gonorrhoeae?

2017 ◽  
Author(s):  
Michelle Cole ◽  
Anthony Underwood ◽  
Kate Templeton ◽  
Jill Shepherd ◽  
Gwenda Hughes ◽  
...  
Keyword(s):  
Low Level ◽  
High Level ◽  
Azithromycin Resistance ◽  
Level Resistance

scholarly journals Association among biofilm formation, virulence gene expression, and antibiotic resistance in Proteus mirabilis isolates from diarrhetic animals in northeast China

2020 ◽  
Author(s):  
Yadong Sun ◽  
Shanshan Wen ◽  
Lili Zhao ◽  
Qiqi Xia ◽  
Yue Pan ◽  
...  
Keyword(s):  
Gene Expression ◽  
Antibiotic Resistance ◽  
Biofilm Formation ◽  
Northeast China ◽  
Virulence Gene ◽  
Drug Susceptibility ◽  
Multidrug Resistant ◽  
Virulence Gene Expression ◽  
Biofilm Production ◽  
High Level

Abstract Background The aim of this study was to investigate the association among biofilm formation, virulence gene expression, and antibiotic resistance in P. mirabilis isolates collected from diarrhetic animals (n = 176) in northeast China between September 2014 and October 2016. Results Approximately 92.05% of the isolates were biofilm producers, whereas 7.95% of the isolates were non-producers. The prevalence of virulence genes in biofilm producers was significantly higher than that in non-producers. Biofilm production was significantly associated with the expression of ureC , zapA , rsmA , hmpA , mrpA , atfA , and pmfA ( P < 0.05). Drug susceptibility tests revealed that approximately 76.7% of the isolates were multidrug-resistant (MDR) and extensively drug-resistant (XDR). Biofilm production was significantly associated with resistance to doxycycline, tetracycline, sulfamethoxazole, kanamycin, and cephalothin ( P < 0.05). Although the pathogenicity of the biofilm producers was stronger than that of the non-producers, the biofilm-forming ability of the isolates was not significantly associated with morbidity and mortality in mice ( P > 0.05). Conclusion Our findings suggested that a high level of multidrug resistance in diarrhetic animals infected with P. mirabilis in northeast China.The results of this study indicated that the positive rates of the genes expressed by biofilm-producing P. mirabilis isolates were significantly higher than those expressed by non-producing isolates.

scholarly journals Integrative and Conjugative Element-Mediated Azithromycin Resistance in Multidrug-Resistant Salmonella enterica Serovar Albany

2021 ◽  
Vol 65 (5) ◽  
Author(s):  
Yu-Ping Hong ◽  
Ying-Tsong Chen ◽  
You-Wun Wang ◽  
Bo-Han Chen ◽  
Ru-Hsiou Teng ◽  
...  
Keyword(s):  
Vibrio Cholerae ◽  
Salmonella Enterica ◽  
Multidrug Resistant ◽  
Content Type ◽  
Human Salmonellosis ◽  
High Level ◽  
Azithromycin Resistance ◽  
Level Resistance ◽  
Integrative And Conjugative Element

ABSTRACT We identified an erm42-carrying integrative and conjugative element, ICE_erm42, in 26.4% of multidrug-resistant Salmonella enterica serovar Albany isolates recovered from cases of human salmonellosis between 2014 and 2019 in Taiwan. ICE_erm42-carrying strains displayed high-level resistance to azithromycin, and the element could move into the phylogenetically distant species Vibrio cholerae via conjugation.

scholarly journals Comparison of Methicillin-Resistant Staphylococcus aureus Isolates from Cellulitis and from Osteomyelitis in a Taiwan Hospital, 2016–2018

2019 ◽  
Vol 8 (6) ◽  
pp. 816 ◽  
Author(s):  
Kuo-Ti Peng ◽  
Tsung-Yu Huang ◽  
Yao-Chang Chiang ◽  
Yu-Yi Hsu ◽  
Fang-Yi Chuang ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Joint Infection ◽  
Sccmec Type ◽  
Multidrug Resistant ◽  
Chang Gung Memorial Hospital ◽  
Methicillin Resistant ◽  
Mrsa Strains ◽  
Resistance Rates

Methicillin-resistant Staphylococcus aureus (MRSA) causes superficial infections such as cellulitis or invasive infections such as osteomyelitis; however, differences in MRSA isolates from cellulitis (CL-MRSA) and from osteomyelitis (OM-MRSA) at the same local area remain largely unknown. A total of 221 MRSA isolates including 106 CL-MRSA strains and 115 OM-MRSA strains were collected at Chang-Gung Memorial Hospital in Taiwan between 2016 and 2018, and their genotypic and phenotypic characteristics were compared. We found that OM-MRSA isolates significantly exhibited higher rates of resistance to multiple antibiotics than CL-MRSA isolates. Genotypically, OM-MRSA isolates had higher proportions of the SCCmec type III, the sequence type ST239, and the spa type t037 than CL-MRSA isolates. Besides the multidrug-resistant lineage ST239-t037-SCCmecIII more prevalent in OM-MRSA, higher antibiotic resistance rates were also observed in several other prevalent lineages in OM-MRSA as compared to the same lineages in CL-MRSA. Furthermore, when prosthetic joint infection (PJI) associated and non-PJI-associated MRSA strains in osteomyelitis were compared, no significant differences were observed in antibiotic resistance rates between the two groups, albeit more diverse genotypes were found in non-PJI-associated MRSA. Our findings therefore suggest that deep infections may allow MRSA to evade antibiotic attack and facilitate the convergent evolution and selection of multidrug-resistant lineages.

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