Prevalence and Genetic Characteristics of Staphylococcus aureus CC398 Isolates From Invasive Infections in Spanish Hospitals, Focusing on the Livestock-Independent CC398-MSSA Clade

BackgroundLivestock-associated (LA)-CC398-MRSA is closely related to pigs, being unfrequently detected in human invasive infections. CC398-MSSA is emerging in human invasive infections in some countries, but genetic and epidemiological characteristics are still scarcely reported.ObjectivesTo determine the prevalence of Staphylococcus aureus (SA) CC398, both MRSA and MSSA, among blood cultures SA isolates recovered in Spanish hospitals located in regions with different pig-farming densities (PD) and characterize the recovered isolates.MethodsOne thousand twenty-two SA isolates (761 MSSA, 261 MRSA) recovered from blood cultures during 6–12 months in 17 Spanish hospitals (2018–2019) were studied. CC398 lineage identification, detection of spa-types, and antibiotic resistance, virulence and human immune evasion cluster (IEC) genes were analyzed by PCR/sequencing.ResultsForty-four CC398-MSSA isolates (4.3% of SA; 5.8% of MSSA) and 10 CC398-MRSA isolates (1% of SA; 3.8% of MRSA) were detected. Eleven spa-types were found among the CC398-MSSA isolates with t571 and t1451 the most frequent spa-types detected (75%). Most of CC398-MSSA isolates were Immune-Evasion-Cluster (IEC)-positive (88.6%), tetracycline-susceptible (95.5%) and erythromycin/clindamycin–inducible-resistant/erm(T)-positive (75%). No statistical significance was detected when the CC398-MSSA/MSSA rate was correlated to PD (pigs/km2) (p = 0.108). On the contrary, CC398-MRSA isolates were all IEC-negative, predominately spa-t011 (70%), and the CC398-MRSA/MRSA rate was significantly associated to PD (p < 0.005).ConclusionCC398-MSSA is an emerging clade in invasive infections in Spanish hospitals. CC398-MRSA (mostly t011) and CC398-MSSA (mostly t571 and t1451) show important differences, possibly suggesting divergent steps in host-adaptation evolutionary processes. While CC398-MRSA is livestock-associated (lacking IEC-system), CC398-MSSA seems to be mostly livestock-independent, carrying human-adaptation markers.

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Presence of Immune Evasion Cluster and Molecular Typing of Methicillin-Susceptible Staphylococcus aureus Isolated from Food Handlers

Journal of Food Protection ◽

10.4315/0362-028x.jfp-15-401 ◽

2016 ◽

Vol 79 (4) ◽

pp. 682-686 ◽

Cited By ~ 2

Author(s):

LÍVIA G. BAPTISTÃO ◽

NATHALIA C. C. SILVA ◽

ERIKA C. R. BONSAGLIA ◽

BRUNA F. ROSSI ◽

IVANA G. CASTILHO ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Immune Evasion ◽

Close Contact ◽

Meca Gene ◽

Low Frequency ◽

Food Handlers ◽

Spa Typing ◽

Typing Method ◽

Spa Types ◽

Immune Evasion Cluster

ABSTRACT The hands and noses of food handlers colonized by Staphylococcus aureus are an important source of food contamination in restaurants and food processing. Several virulence factors can be carried by mobile elements in strains of S. aureus, including the immune evasion cluster (IEC). This gene cluster improves the capacity of S. aureus to evade the human immune response. Many studies have reported the transmission of strains between animals and humans, such as farm workers that have close contact with livestock. However, there are few studies on the transmission between food and food handlers. The aim of this study was to detect the IEC and the mecA gene in strains isolated from food handlers and to type these strains using the spa typing method. Thirty-five strains of S. aureus isolated from the noses and hands of food handlers in three different kitchens were analyzed for the presence of the mecA gene and IEC and by spa typing. All strains were negative for the mecA gene, and the presence of IEC was observed in 10 (28.6%) strains. Fifteen different spa types were observed, with the most frequent being t127 (42.85%) and t002 (11.42%). Strains from the two most prevalent spa types and a novel spa type were typed by multilocus sequence typing. spa types t127, t002, and t13335 were determined to be multilocus sequence types (ST) ST-30, ST-5, and ST-45, respectively. The food handlers may have been contaminated by these strains of S. aureus through food, which is suggested by the low frequency of IEC and by ST that are observed more commonly in animals.

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Molecular Study of Immune Evasion Cluster Genes in Clinical Isolates of Staphylococcus aureus

Current Biotechnology ◽

10.2174/2211550110666211029123127 ◽

2021 ◽

Vol 10 ◽

Author(s):

Maysaa El Sayed Zaki ◽

Samah Sabry El-Kazzaz

Keyword(s):

Staphylococcus Aureus ◽

Immune Evasion ◽

Clinical Isolates ◽

Diffusion Method ◽

Beta Lactam ◽

Sensitivity Testing ◽

Cross Sectional ◽

Methicillin Resistant ◽

Beta Lactam Antibiotics ◽

Immune Evasion Cluster

Aims: The aim of the present research was to highlight the prevalence of immune evasion cluster genes (IEC) sak, chp, scn, sea, sep among Staphylococcus aureus (S. aureus) clinical isolates. Background: The present study was a cross-sectional retrospective study, included one hundred isolates of S. aureus that were isolated from patients with nosocomial infections. S. aureus isolates were subjected to full microbiological identification and antibiotics sensitivity testing by the disc diffusion method. The presence of IEC genes scn, sea, sak, sep, chp was determined by polymerase chain reaction (PCR). Methods: The current study included 100 S. aureus isolates; 40% were classified as methicillin resistant. The isolates exhibited marked resistance to beta lactams antibiotics, the lowest resistance was to erythromycin, ciprofloxacin and vancomycin. The presence of one or more IEC was determined in 89 isolates. The prevalence of chp, sak, sea, sep and scn was 54%, 53%, 8%, 7% and 30%, respectively. Results: S. aureus isolates with IEC genes had increased resistance rates to the studied antibiotics; however, this increase was statistically insignificant either to beta-lactam antibiotics, such as amoxacillin/clavulinic acid (P=0.794), ampicillin (P=0.561), cefotaxim (P=0.271), ceftazidime (P=0.145), imipenem (P=0.589) or non beta-lactam antibiotics, such as amikacin (P=0.955) and trimethoprim/sulfamethoxazale (P=0.974). From 40 methicillin resistant Staphylococcus aureus (MRSA) strains, 37 isolates harbor one or more immune evasion cluster genes. Conclusion: The high prevalence of these genes among MRSA may explain its pathogenesis. There is a need for studies with a high number of isolates to verify the present findings.

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9. The Skip Phenomenon in Staphylococcus aureus Bacteremia: Clinical Associations

Open Forum Infectious Diseases ◽

10.1093/ofid/ofab466.009 ◽

2021 ◽

Vol 8 (Supplement_1) ◽

pp. S7-S8

Author(s):

John Raymond U Go ◽

Larry M Baddour ◽

Brian Lahr ◽

Muhammad R Sohail ◽

Raj Palraj

Keyword(s):

Staphylococcus Aureus ◽

Statistical Significance ◽

Hospital Length ◽

Blood Cultures ◽

Hospital Length Of Stay ◽

Clinical Microbiology Laboratory ◽

Staphylococcus Aureus Bacteremia ◽

Increased Risk ◽

Antibiotic Duration ◽

Using Data

Abstract Background Serial blood cultures are integral in managing Staphylococcus aureus bacteremia (SAB) as clinicians rely on the results to determine infectious complication risks and antibiotic duration. Current IDSA guidelines suggest a single set of negative blood cultures is adequate evidence of SAB clearance. Several studies, however, have identified the skip phenomenon (SP), which is the occurrence of intermittent negative blood cultures, and have recommended obtaining additional blood cultures to document bacterial clearance (Table 1). We therefore examined patients who manifested the SP to determine its clinical significance and to study this, associations were tested for SP in relation to various baseline factors as well as clinical outcomes. Methods We performed a retrospective, multicenter study of all patients with a positive blood culture for S. aureus from January 2019 to December 2019 using data collected from electronic health records and the clinical microbiology laboratory. Results A total of 602 patients with SAB were identified and 495 patients were included in the investigation (Figure 1). Overall, 25 (5.1%) patients had the SP. Significant differences between those who did and did not manifest the SP included higher rates of injection drug use, automatic implantable cardioverter defibrillator, and community onset of infection in the SP cohort (Table 2). Moreover, the median duration of SAB was longer (3.2 [2.3-5.4] vs 1.90 [1.2-2.9] days, p=0.002), and high-grade SAB, (88.0% vs 58.7%, p=0.004), complicated bacteremia (92.0% vs 67.9%, p=0.011) and IE diagnosis (28.0% vs 11.3%, p=0.013) were all more common in the SP group. In unadjusted outcome analyses, association of SP with hospital length of stay was not significant, although a higher risk of in-hospital mortality among SP patients approached statistical significance (p=0.055). Analysis of 435 hospital survivors revealed no significant differences in rates of 1-year mortality or 90-day relapse between the two groups (Table 3). Conclusion Findings of the current investigation demonstrates an increased risk of SAB complications in patients with the SP and support the notion that serial negative blood cultures are needed to document clearance of SAB. Disclosures Larry M. Baddour, MD, Boston Scientific (Individual(s) Involved: Self): Consultant; Botanix Pharmaceuticals (Individual(s) Involved: Self): Consultant; Roivant Sciences (Individual(s) Involved: Self): Consultant Muhammad R. Sohail, MD, Medtronic (Consultant)Philips (Consultant)

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Genetic Lineages, Antimicrobial Resistance, and Virulence in Staphylococcus aureus of Meat Samples in Spain: Analysis of Immune Evasion Cluster (IEC) Genes

Foodborne Pathogens and Disease ◽

10.1089/fpd.2013.1689 ◽

2014 ◽

Vol 11 (5) ◽

pp. 354-356 ◽

Cited By ~ 20

Author(s):

Daniel Benito ◽

Paula Gómez ◽

Carmen Lozano ◽

Vanesa Estepa ◽

Elena Gómez-Sanz ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Antimicrobial Resistance ◽

Immune Evasion ◽

Genetic Lineages ◽

Meat Samples ◽

Immune Evasion Cluster

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Bacteriophages encoding human immune evasion factors adapt to livestock-associated MRSA through rounds of integration and excision

10.1101/2021.04.29.441770 ◽

2021 ◽

Author(s):

Helena Leinweber ◽

Raphael Sieber ◽

Jesper Larsen ◽

Marc Stegger ◽

Hanne Ingmer

Keyword(s):

Staphylococcus Aureus ◽

Immune Evasion ◽

Attachment Site ◽

Bacterial Attachment ◽

Adaptive Mutations ◽

Integration Sites ◽

Human Immune ◽

Bacterial Viruses ◽

Human Infections ◽

Model Strain

AbstractIn recent years there has been an increase in human infections with methicillin-resistant Staphylococcus aureus (MRSA) originating from livestock and strains carrying bacterial viruses of the Sa3int-family have disseminated into the community. Sa3int phages express immune evasion factors and are common in human staphylococcal strains. As the bacterial attachment site (attB) for Sa3int phages is mutated in livestock-associated strains, the integration frequency is low and a key question is how the phages are established. Here we show that Sa3int phages adapt to alternative bacterial integration sites by mutating the phage attachment sequence, attP, leading to enhanced integration at these sites. Using a model strain carrying the mutated attBLA of livestock-associated strains we find that once established, the Sa3int phage, Φ13 is inducible with release of heterogenous phage populations carrying mutations in attP that in part increase homology to alternative integration sites or attBLA. Compared to the original phage, the adaptive mutations increase phage integration in new rounds of infection. Also, Sa3int phages induced from livestock-associated outbreak strains reveal mutated attP sequences. We suspect that promiscuity of the phage-encoded recombinase allows this adaptation and propose it may explain how phages mediate “host jumps” that are regularly observed for staphylococcal lineages.

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Immune evasion cluster-positive bacteriophages are highly prevalent among human Staphylococcus aureus strains, but they are not essential in the first stages of nasal colonization

Clinical Microbiology and Infection ◽

10.1111/j.1469-0691.2010.03227.x ◽

2011 ◽

Vol 17 (3) ◽

pp. 343-348 ◽

Cited By ~ 45

Author(s):

N.J. Verkaik ◽

M. Benard ◽

H.A. Boelens ◽

C.P. de Vogel ◽

J.L. Nouwen ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Immune Evasion ◽

Nasal Colonization ◽

Immune Evasion Cluster

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Staphylococcal nasal carriage in calves: multiresistant Staphylococcus sciuri and immune evasion cluster (IEC) genes in methicillin-resistant Staphylococcus aureus ST398

Journal of Antimicrobial Chemotherapy ◽

10.1093/jac/dkr196 ◽

2011 ◽

Vol 66 (8) ◽

pp. 1927-1928 ◽

Cited By ~ 16

Author(s):

Marisa Haenni ◽

Pierre Châtre ◽

Sandrine Boisset ◽

Anne Carricajo ◽

Michèle Bes ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Immune Evasion ◽

Methicillin Resistant Staphylococcus Aureus ◽

Nasal Carriage ◽

Methicillin Resistant ◽

Immune Evasion Cluster

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Methicillin-Resistant Staphylococcus aureus from Peninsular Malaysian Animal Handlers: Molecular Profile, Antimicrobial Resistance, Immune Evasion Cluster and Genotypic Categorization

Antibiotics ◽

10.3390/antibiotics11010103 ◽

2022 ◽

Vol 11 (1) ◽

pp. 103

Author(s):

Minhian Chai ◽

Muhammad Zikree Sukiman ◽

Amirah Huda Kamarun Baharin ◽

Insyirah Ramlan ◽

Lennard Zhunhoong Lai ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Antimicrobial Resistance ◽

Immune Evasion ◽

Methicillin Resistant Staphylococcus Aureus ◽

Peninsular Malaysia ◽

Molecular Techniques ◽

Molecular Profile ◽

Methicillin Resistant ◽

Immune Evasion Cluster ◽

Animal Handlers

Staphylococcus aureus (S. aureus) infections, particularly methicillin-resistant Staphylococcus aureus (MRSA) in humans and animals, have become a significant concern globally. The present study aimed to determine the prevalence and antibiogram of S. aureus isolated from animal handlers in Peninsular Malaysia. Furthermore, the genotypic characteristics of S. aureus isolates were also investigated. Nasal and oral swab samples were collected from 423 animal handlers in Peninsular Malaysia. The antibiogram profiles of S. aureus against 18 antibiotics were established using a Kirby–Bauer test. The genotypic profile of S. aureus, including the presence of antimicrobial resistance (AMR), virulence genes and spa genotypes, was investigated using molecular techniques. The overall carriage rate of S. aureus, MRSA and MDRSA was 30.5%, 1.2% and 19.4%, respectively. S. aureus was highly resistant against penicillin (72.3%) and amoxicillin (52.3%). Meanwhile, gentamicin and linezolid were fully effective against all the isolated S. aureus from animal handlers. It was observed that animal handlers with close exposure to poultry were more likely to carry S. aureus that is resistant to tetracycline and erythromycin. S. aureus isolates harboured tetracycline resistance (tetK, tetL and tetM), erythromycin resistance (ermA, ermB, ermC and msrA) and immune evasion cluster (IEC) genes (scn, chp, sak, sea and sep). Seventeen different spa types were detected among the 30 isolates of MDRSA, with t189 (16.7%) and t4171 (16.7%) being the predominant spa type, suggesting wide genetic diversity of the MDRSA isolates. The present study demonstrated the prevalence of S. aureus strains, including MRSA and MDRSA with various antimicrobial resistance and genetic profiles from animal handlers in Peninsular Malaysia.

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