Coagulase-negative staphylococcal bloodstream and prosthetic-device-associated infections: the role of biofilm formation and distribution of adhesin and toxin genes

Coagulase-negative staphylococci (CNS), especially Staphylococcus epidermidis and Staphylococcus haemolyticus, have emerged as opportunistic pathogens in immunocompromised patients and those with indwelling medical devices. In this study, CNS recovered from patients with bloodstream infections (BSIs) or prosthetic-device-associated infections (PDAIs) were compared in terms of biofilm formation, antimicrobial resistance, clonal distribution, and carriage of adhesin and toxin genes. A total of 226 CNS isolates (168 S. epidermidis and 58 S. haemolyticus) recovered from hospital inpatients with BSIs (100 isolates) or PDAIs (126 isolates) were tested for biofilm formation, antimicrobial susceptibility, and mecA, ica operon, adhesin (aap, bap, fnbA, atlE, fbe) and toxin (tst, sea, sec) genes. The selected CNS were classified into pulsotypes by PFGE and assigned to sequence types by multilocus sequence typing. In total, 106/226 isolates (46.9 %) produced biofilm, whereas 150 (66.4 %) carried the ica operon. Most isolates carried mecA and were multidrug resistant (90.7 %). CNS recovered from BSIs were significantly more likely to produce biofilm (P = 0.003), be resistant to antimicrobials and carry mecA (P<0.001), as compared with isolates derived from PDAIs. CNS from PDAIs were more likely to carry the aap and bap genes (P = 0.006 and P = 0.045, respectively). No significant differences in the carriage of toxin genes were identified (P>0.05). Although PFGE revealed genetic diversity, especially among S. epidermidis, analysis of representative strains from the main PFGE types by multilocus sequence typing revealed three major clones (ST2, ST5 and ST16). A clonal relationship was found with respect to antimicrobial susceptibility and ica and aap gene carriage, reinforcing the premise of clonal expansion in hospital settings. The results of this study suggest that the pathogenesis of BSIs is associated with biofilm formation and high-level antimicrobial resistance, whereas PDAIs are related to the adhesion capabilities of S. epidermidis and S. haemolyticus strains.

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Phenotypic and Molecular Characterization of Plasmid-Mediated Virulence and Antimicrobial Resistance Traits among Multidrug Resistant Enterococcus spp. in Egypt

Journal of Pure and Applied Microbiology ◽

10.22207/jpam.14.3.03 ◽

2020 ◽

Vol 14 (3) ◽

pp. 1649-1661

Author(s):

Mahmoud M. Tawfick ◽

Nagwan G. El Menofy ◽

Maha E. Omran ◽

Omnia A. Alsharony ◽

Maha A. Abo-Shady

Keyword(s):

Antimicrobial Resistance ◽

Resistance Genes ◽

Antimicrobial Susceptibility ◽

Biofilm Formation ◽

Multidrug Resistant ◽

Control Measures ◽

Diffusion Method ◽

Geographical Regions ◽

Broth Microdilution Method ◽

Enterococcus Spp

Enterococcus spp. are remarkable multidrug resistant (MDR) bacteria that are causing serious healthcare-associated infections. The current study investigated the frequency of Enterococcus spp., antimicrobial susceptibility, biofilm formation and the presence of some plasmid-mediated virulence characters and antimicrobial resistance determinants in enterococcal isolates from Egyptian hospitals in Cairo. Enterococcus bacterial isolates were recovered from different clinical specimens and identified using biochemical testing and KB005A HiStrep™ identification kit. Kirby-Bauer disc diffusion method and/or broth microdilution method were used to determine the antimicrobial susceptibility patterns. Phenotypic assays were performed to study biofilm formation and cytolysin and gelatinase production. PCR assays targeting the plasmid-carried genes aac(6’)-aph(2’), aph(3)-IIIa, vanA, agg and cylA were performed. In this study, 50 isolates of diverse Enterococcus spp. were identified with E. faecium was the most frequently isolated one. High resistance profiles were determined against tested antimicrobials and all isolates were MDR. Moderate biofilm formation was detected in 20% of isolates, 18% showed complete blood hemolysis and 12% produced gelatinase. All isolates carried the tested aminoglycosides resistance genes, while vanA was found only in 4 isolates (8%). The virulence genes agg and cylA were detected in 4% and 32% of isolates, respectively. In conclusion, E. faecium was the most prevalent species. The entire isolates set were MDR and the plasmid-carried aminoglycoside resistance genes were extensively disseminated among MDR isolates. Thus, regular surveillance studies, from the area of study or other geographical regions in Egypt, and strict infection control measures are required to monitor the emerging MDR enterococci.

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Molecular Typing and Antimicrobial Susceptibility Profile of Staphylococcus aureus Isolates Recovered from Bovine Mastitis and Nasal Samples

10.20944/preprints202009.0115.v1 ◽

2020 ◽

Author(s):

Renata P. Santos ◽

Fernando N. Souza ◽

Ana Claudia C. Oliveira ◽

Antônio F. de Souza Filho ◽

Juliana Aizawa ◽

...

Keyword(s):

Antimicrobial Resistance ◽

Antimicrobial Susceptibility ◽

Protein A ◽

Bovine Mastitis ◽

Multidrug Resistant ◽

Aureus Strain ◽

Staphylococcal Protein A ◽

Spa Typing ◽

Antimicrobial Susceptibility Profile ◽

High Level

In the present study, we aimed to determine the antimicrobial resistance and genetic structure of a population of S. aureus recovered from transient and persistent intramammary infections and nares/muzzles. We investigated the antimicrobial resistance of 189 S. aureus strains using a broad antimicrobial susceptibility profile. Furthermore, 107 S. aureus isolates were strain-typed using staphylococcal protein-A (spa) typing. Here, a great proportion of strains exhibited multidrug resistance to antimicrobials, including resistance to critically important antimicrobials, although no methicillin-resistant S. aureus strains were found. Our study did not strengthen the idea that extramammary niches (i.e., nares/muzzles) are an important source for S. aureus. A discrepancy in the antimicrobial resistance between S. aureus strains isolated from nasal/muzzles and milk samples was observed. Furthermore, S. aureus isolates from transient and persistent IMIs did not differ by spa typing, suggesting that the persistence of bovine IMIs was determined by cow factors. Thus, the high level of multidrug-resistant S. aureus found in the two herds studied together with the predominance of a well udder-adapted S. aureus strain may contribute to the history of the high prevalence of mastitis caused by S. aureus, leading to great animal and public health concerns.

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Frequency of Blood Culture Isolates and their Antibiogram in a Teaching Hospital

Journal of Nepal Medical Association ◽

10.31729/jnma.2295 ◽

2014 ◽

Vol 52 (193) ◽

pp. 692-696 ◽

Cited By ~ 5

Author(s):

Subha Shrestha ◽

Ritu Amatya ◽

Raj Kumari Shrestha ◽

Rajiv Shrestha

Keyword(s):

Staphylococcus Aureus ◽

Klebsiella Pneumoniae ◽

Teaching Hospital ◽

Antimicrobial Susceptibility ◽

Salmonella Enterica ◽

Bloodstream Infections ◽

Blood Stream ◽

Coagulase Negative Staphylococci ◽

Ongoing Surveillance ◽

High Level

Introduction: Bloodstream infections are associated with significant patient morbidity and mortality. Antimicrobial susceptibility patterns should guide the choice of empiric antimicrobial regimens for patients with bacteremia.Methods: Blood sample received from the patient attending Nepal Medical College and Teaching Hospital from March 2013 – August, 2013 were subjected to for culture. Isolate identification and antimicrobial susceptibility testing was done by standard microbiological methodResults: Out of the total 2,766 blood samples, 13.3% showed bacterial growth. The percentage of neonatal septicemia was 13.3%. Staphylococcus aureus (28%) was the most common isolates followed by Salmonella enterica Serotype Typhi (22%), Coagulase negative Staphylococci (9.5%), Salmonella enterica Serotype Paratyphi ((7.6%) and Klebsiella pneumoniae (7.6%). 26.3% of the isolates of Staphylococcus aureus were oxacillin resistant. Most of the gram positive organisms were susceptible to amikacin and vancomycin and showed high level resistance to cefuroxime and cotrimoxazole. Out of 109 isolates of typhoid bacilli, 95.3% were resistant to nalidixic acid ,79% to ciprofloxacin and 60.5% to ofloxacin. More than 50% of the isolates of Klebsiella pneumoniae and Escherichia coli showed resistance to cephalosporins and cotrimoxazole. Acinetobacter spp showed high resistance (more than 60%) to ceftriaxone and ofloxacin. More than 20% of the isolates of Pseudomonas aeruginosa were resistant to ciprofloxacin and amikacin.Conclusions: Ongoing surveillance for antimicrobial susceptibility remains essential, and will enhance efforts to identify resistance and attempt to limit its spread.Keywords: antibiotic; bacteria; blood stream infections.

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First Case of Staphylococci Carrying Linezolid Resistance Genes from Laryngological Infections in Poland

Pathogens ◽

10.3390/pathogens10030335 ◽

2021 ◽

Vol 10 (3) ◽

pp. 335

Author(s):

Michał Michalik ◽

Maja Kosecka-Strojek ◽

Mariola Wolska ◽

Alfred Samet ◽

Adrianna Podbielska-Kubera ◽

...

Keyword(s):

Antimicrobial Resistance ◽

Resistance Genes ◽

Ribosomal Proteins ◽

Multidrug Resistant ◽

Aureus Strain ◽

Coagulase Negative Staphylococci ◽

Spa Typing ◽

Linezolid Resistance ◽

First Case ◽

Resistance Patterns

Linezolid is currently used to treat infections caused by multidrug-resistant Gram-positive cocci. Both linezolid-resistant S. aureus (LRSA) and coagulase-negative staphylococci (CoNS) strains have been collected worldwide. Two isolates carrying linezolid resistance genes were recovered from laryngological patients and characterized by determining their antimicrobial resistance patterns and using molecular methods such as spa typing, MLST, SCCmec typing, detection of virulence genes and ica operon expression, and analysis of antimicrobial resistance determinants. Both isolates were multidrug resistant, including resistance to methicillin. The S. aureus strain was identified as ST-398/t4474/SCCmec IVe, harboring adhesin, hemolysin genes, and the ica operon. The S. haemolyticus strain was identified as ST-42/mecA-positive and harbored hemolysin genes. Linezolid resistance in S. aureus strain was associated with the mutations in the ribosomal proteins L3 and L4, and in S. haemolyticus, resistance was associated with the presence of cfr gene. Moreover, S. aureus strain harbored optrA and poxtA genes. We identified the first case of staphylococci carrying linezolid resistance genes from patients with chronic sinusitis in Poland. Since both S. aureus and CoNS are the most common etiological factors in laryngological infections, monitoring of such infections combined with surveillance and infection prevention programs is important to decrease the number of linezolid-resistant staphylococcal strains.

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Serotype distribution, antimicrobial susceptibility, antimicrobial resistance genes and virulence genes of Salmonella isolated from a pig slaughterhouse in Yangzhou, China

AMB Express ◽

10.1186/s13568-019-0936-9 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 2

Author(s):

Quan Li ◽

Jian Yin ◽

Zheng Li ◽

Zewei Li ◽

Yuanzhao Du ◽

...

Keyword(s):

Public Health ◽

Antimicrobial Resistance ◽

Resistance Genes ◽

Antimicrobial Susceptibility ◽

Virulence Genes ◽

Multidrug Resistant ◽

Resistance Rate ◽

Economic Losses ◽

Production Chain ◽

Antimicrobial Resistance Genes

AbstractSalmonella is an important food-borne pathogen associated with public health and high economic losses. To investigate the prevalence and the characteristics of Salmonella in a pig slaughterhouse in Yangzhou, a total of 80 Salmonella isolates were isolated from 459 (17.43%) samples in 2016–2017. S. Derby (35/80, 43.75%) was the most prevalent, followed by S. Rissen (16/80, 20.00%) and S. Newlands (11/80, 13.75%). The highest rates of susceptibility were observed to cefoxitin (80/80, 100.0%) and amikacin (80/80, 100.0%), followed by aztreonam (79/80, 98.75%) and nitrofurantoin (79/80, 98.75%). The highest resistance rate was detected for tetracycline (65/80, 81.25%), followed by ampicillin (60/80, 75.00%), bactrim (55/80, 68.75%), and sulfisoxazole (54/80, 67.50%). Overall, 91.25% (73/80) of the isolates were resistant to at least one antibiotic, while 71.25% (57/80) of the isolate strains were multidrug resistant in the antimicrobial susceptibility tested. In addition, 86.36% (19/22) of the 22 antimicrobial resistance genes in the isolates were identified. Our data indicated that the resistance to certain antimicrobials was significantly associated, in part, with antimicrobial resistance genes. Furthermore, 81.25% (65/80) isolates harbored the virulence gene of mogA, of which 2 Salmonella Typhimurium isolates carried the mogA, spvB and spvC virulence genes at the same time. The results showed that swine products in the slaughterhouse were contaminated with multidrug resistant Salmonella commonly, especially some isolates carry the spv virulence genes. The virulence genes might facilitate the dissemination of the resistance genes to consumers along the production chain, suggesting the importance of controlling Salmonella during slaughter for public health.

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Genomic Analysis of Multiresistant Staphylococcus capitis Associated with Neonatal Sepsis

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00898-18 ◽

2018 ◽

Vol 62 (11) ◽

Cited By ~ 11

Author(s):

Glen P. Carter ◽

James E. Ussher ◽

Anders Gonçalves Da Silva ◽

Sarah L. Baines ◽

Helen Heffernan ◽

...

Keyword(s):

Neonatal Sepsis ◽

Neonatal Intensive Care ◽

Genomic Analysis ◽

Bloodstream Infections ◽

Multidrug Resistant ◽

Comparative Genomic ◽

Coagulase Negative Staphylococci ◽

Content Type ◽

Staphylococcus Capitis ◽

Hospital Infection Control

ABSTRACT Coagulase-negative staphylococci (CoNS), such as Staphylococcus capitis, are major causes of bloodstream infections in neonatal intensive care units (NICUs). Recently, a distinct clone of S. capitis (designated S. capitis NRCS-A) has emerged as an important pathogen in NICUs internationally. Here, 122 S. capitis isolates from New Zealand (NZ) underwent whole-genome sequencing (WGS), and these data were supplemented with publicly available S. capitis sequence reads. Phylogenetic and comparative genomic analyses were performed, as were phenotypic assessments of antimicrobial resistance, biofilm formation, and plasmid segregational stability on representative isolates. A distinct lineage of S. capitis was identified in NZ associated with neonates and the NICU environment. Isolates from this lineage produced increased levels of biofilm, displayed higher levels of tolerance to chlorhexidine, and were multidrug resistant. Although similar to globally circulating NICU-associated S. capitis strains at a core-genome level, NZ NICU S. capitis isolates carried a novel stably maintained multidrug-resistant plasmid that was not present in non-NICU isolates. Neonatal blood culture isolates were indistinguishable from environmental S. capitis isolates found on fomites, such as stethoscopes and neonatal incubators, but were generally distinct from those isolates carried by NICU staff. This work implicates the NICU environment as a potential reservoir for neonatal sepsis caused by S. capitis and highlights the capacity of genomics-based tracking and surveillance to inform future hospital infection control practices aimed at containing the spread of this important neonatal pathogen.

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A Comprehensive Review on Current Progressions in Combating The Antimicrobial Resistance

International Journal of Research in Pharmaceutical Sciences ◽

10.26452/ijrps.v11i2.2023 ◽

2020 ◽

Vol 11 (2) ◽

pp. 1493-1504

Author(s):

Bharatlal Sain ◽

Manohar M ◽

Gowda D V

Keyword(s):

Photodynamic Therapy ◽

Antimicrobial Resistance ◽

Antimicrobial Susceptibility ◽

Biofilm Formation ◽

Susceptibility Testing ◽

Persister Cells ◽

Comprehensive Review ◽

Obligate Intracellular ◽

Competitive Inhibitors ◽

The World

Anti-microbial resistance (AMR) is the ability of a microbe to resist the effect of antibiotics. It has become the most important cause of concern throughout the world. AMR may develop a variety of mechanisms, including resistance, weakness or due to a certain therapeutic failure. The three major causes of resistance were identified to be over usage of anti-microbials, over-prescription, increased agricultural usage. The mechanism which leads to the development of AMR were found to be Metabolic Inactive Persister cells biofilm formation, Swarming, Obligate intracellular microbes, Reduced uptake and efflux pumps, Modification of the antibiotic binding site, Production of competitive inhibitors. Research is still being carried out and few methods successfully delay or inhibit the progress of Resistance namely: Photodynamic therapy, which works on the principle of photosensitization, results in formation of ROS which destroy pathogenic cells, Vaccines, which strengthen the defence system to fight against foreign microorganisms efficiently, Antibiotic adjuvants, work by inhibiting any kind of mechanism related to the resistance increasing the drug’s antibacterial efficiency, Nano antibiotics which acts by interfering with the mechanisms for the development of the resistance and microfluidics give a better understanding of the bacteria and its superior antimicrobial susceptibility testing. Hence, in this review the above mechanisms of antimicrobial resistance as well the latest AMR combating strategies are been discussed.

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

10.21203/rs.2.16502/v2 ◽

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.

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Antimicrobial Susceptibility and Clonality of Vaginally Derived Multidrug-Resistant Mobiluncus Isolates in China

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00780-20 ◽

2020 ◽

Vol 64 (8) ◽

Author(s):

Xueying Zhang ◽

Yongying Bai ◽

Long Zhang ◽

Mohamed S. Draz ◽

Zhi Ruan ◽

...

Keyword(s):

Phylogenetic Analysis ◽

Antimicrobial Resistance ◽

Transposable Element ◽

Genome Sequencing ◽

Antimicrobial Susceptibility ◽

Multidrug Resistant ◽

Resistance Mechanisms ◽

Whole Genome ◽

Content Type ◽

High Diversity

ABSTRACT Here, the antimicrobial susceptibility, resistance mechanisms, and clonality of Mobiluncus sp. isolates recovered from gynecological outpatients in China were investigated. Compared to M. mulieris, M. curtisii exhibited higher antimicrobial resistance to metronidazole, clindamycin, and tetracycline. Whole-genome sequencing indicated that the clindamycin resistance gene erm(X) was located on a transposable element, Tn5432, which was composed of two IS1249 sequences. Phylogenetic analysis indicated that Mobiluncus spp. had high diversity, with isolates being grouped into several sporadic clades.

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Characterization of Toxin Genes and Antimicrobial Susceptibility of Staphylococcus aureus from Retail Raw Chicken Meat

Journal of Food Protection ◽

10.4315/0362-028x.jfp-17-309 ◽

2018 ◽

Vol 81 (4) ◽

pp. 528-533 ◽

Cited By ~ 5

Author(s):

SUIXIA LI ◽

PANPAN WANG ◽

JIALIN ZHAO ◽

LUHONG ZHOU ◽

PENGFEI ZHANG ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Antimicrobial Resistance ◽

Antimicrobial Susceptibility ◽

Antimicrobial Agents ◽

Health Hazard ◽

Toxin Gene ◽

Potential Health ◽

Toxin Genes ◽

Genes Encoding ◽

Potential Health Hazard

ABSTRACTThe aim of this study was to investigate the toxin gene profile and antimicrobial resistance of Staphylococcus aureus isolates from raw chicken in the People's Republic of China. In total, 289 S. aureus isolates were characterized by antimicrobial susceptibility testing, and genes encoding enterotoxins, exfoliative toxins, Panton-Valentine leukocidin, and toxic shock syndrome toxin were revealed by PCR. Overall, 46.0% of the isolates were positive for one or more toxin genes. A high proportion of toxin genes were pvl (26.6%), followed by sej (12.5%), sea (9.0%), seh (8.3%), seb (6.9%), sec (6.9%), sed (4.8%), sei (3.1%), and see (2.4%). None of the isolates harbored seg, tsst-1, or exfoliative toxin genes. In total, 29 toxin gene profiles were obtained, and pvl (10.7%) was the most frequent genotype, followed by sea (5.9%), seb (4.8%), and sej (4.2%). Furthermore, 99.7% of the strains were resistant to at least one of the tested antimicrobial agents, and 87.2% of them displayed multidrug resistance. Resistance was most frequently observed to trimethoprim-sulfamethoxazole and erythromycin (86.2% for each), followed by tetracycline (69.9%), amoxicillin–clavulanic acid (45.0%), and ampicillin (42.6%). None of the strains were resistant to vancomycin. This study indicates that S. aureus isolates from raw chicken harbored multiple toxin genes and exhibited multiple antimicrobial resistance, which represents a potential health hazard for consumers.

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