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Mupirocin is used for eradicating methicillin-resistant (MRSA) in nasal colonization. A plasmid-borne gene, , is associated with high-level mupirocin resistance. Despite the fact that, among all MRSA from a tertiary care center in the German state of Saxony, the prevalence of , encoding high-level mupirocin resistance, was approximately 1% over a 15-year period from 2000–2015, a sharp increase to nearly 20% was observed in 2016/2017. DNA microarray profiling revealed that this was due to the dissemination of a variant of CC22-MRSA-IV (“Barnim Epidemic Strain” or “UK-EMRSA-15”), which, in addition to , harbors , , , and – in most isolates – (C). In order to prevent therapy failures and a further spread of this strain, the use of mupirocin should be more stringently controlled as well as guided by susceptibility testing. In addition, MRSA decolonization regimens that rely on other substances, such as betaisodona, polyhexanide or octenidine, should be considered.

Background: The effectiveness and reliability of diagnostic tests that detect DNA sequences largely hinge on the quality of the used primers and probes. This importance is especially evident when considering the specific sample being analyzed, as it affects the molecular background and potential for cross-reactivity, ultimately determining the test's performance. Methods: Predicting primers based on the consensus sequence of the target has multiple advantages, including high specificity, diagnostic reliability, broad applicability, and long-term validity. Automated curation of the input sequences ensures high-quality primers and probes. Results: Here, we present a use case for developing a set of consensus primers and probes to identify antibiotic resistance and virulence genes in Staphylococcus (S.) aureus using the ConsensusPrime pipeline. Extensive qPCR experiments with several S. aureus strains confirm the exceptional quality of the primers designed using the pipeline. Conclusions: By improving the quality of the input sequences and using the consensus sequence as a basis, the ConsensusPrime pipeline pipeline ensures high-quality primers and probes, which should be the basis of molecular assays. [ABSTRACT FROM AUTHOR]

The aim of this study was to comprehensively characterise S. aureus from the Caribbean Islands of Trinidad and Tobago, and Jamaica. A total of 101 S. aureus/argenteus isolates were collected in 2020, mainly from patients with skin and soft tissue infections. They were characterised by DNA microarray allowing the detection of ca. 170 target genes and assignment to clonal complexes (CC)s and strains. In addition, the in vitro production of Panton–Valentine leukocidin (PVL) was examined by an experimental lateral flow assay. Two isolates were identified as S. argenteus, CC2596. The remaining S. aureus isolates were assigned to 21 CCs. The PVL rate among methicillin-susceptible S. aureus (MSSA) isolates was high (38/101), and 37 of the 38 genotypically positive isolates also yielded positive lateral flow results. The isolate that did not produce PVL was genome-sequenced, and it was shown to have a frameshift mutation in agrC. The high rate of PVL genes can be attributed to the presence of a known local CC8–MSSA clone in Trinidad and Tobago (n = 12) and to CC152–MSSA (n = 15). In contrast to earlier surveys, the USA300 clone was not found, although one MSSA isolate carried the ACME element, probably being a mecA-deficient derivative of this strain. Ten isolates, all from Trinidad and Tobago, were identified as MRSA. The pandemic ST239–MRSA–III strain was still common (n = 7), but five isolates showed a composite SCCmec element not observed elsewhere. Three isolates were sequenced. That showed a group of genes (among others, speG, crzC, and ccrA/B-4) to be linked to its SCC element, as previously found in some CC5– and CC8–MRSA, as well as in S. epidermidis. The other three MRSA belonged to CC22, CC72, and CC88, indicating epidemiological connections to Africa and the Middle East. [ABSTRACT FROM AUTHOR]

The present study aims to characterise clinical MRSA isolates from a tertiary care centre in Egypt's second-largest city, Alexandria. Thirty isolates collected in 2020 were genotypically characterised by microarray to detect their resistance and virulence genes and assign them to clonal complexes (CC) and strains. Isolates belonged to 11 different CCs and 14 different strains. CC15-MRSA-[V+fus] (n = 6), CC1-MRSA-[V+fus+tir+ccrA/B-1] (PVL+) (n = 5) as well as CC1-MRSA-[V+fus+tir+ccrA/B-1] and CC1153-MRSA-[V+fus] (PVL+) (both with n = 3) were the most common strains. Most isolates (83%) harboured variant or composite SCCmec V or VI elements that included the fusidic acid resistance gene fusC. The SCCmec [V+fus+tir+ccrA/B-1] element of one of the CC1 isolates was sequenced, revealing a presence not only of fusC but also of blaZ, aacA-aphD and other resistance genes. PVL genes were also common (40%). The hospital-acquired MRSA CC239-III strain was only found twice. A comparison to data from a study on strains collected in 2015 (Montelongo et al., 2022) showed an increase in fusC and PVL carriage and a decreasing prevalence of the CC239 strain. These observations indicate a diffusion of community-acquired strains into hospital settings. The beta-lactam use in hospitals and the widespread fusidic acid consumption in the community might pose a selective pressure that favours MRSA strains with composite SCCmec elements comprising mecA and fusC. This is an unsettling trend, but more MRSA typing data from Egypt are required. [ABSTRACT FROM AUTHOR]

In the context of microarray-based epidemiological typing of the clonal organism Staphylococcus aureus /MRSA , a strain was identified that did not belong to known clonal complexes. The molecular analysis by microarray-based typing yielded signals suggesting that it was a mosaic or hybrid strain of two lineages. To verify this result, the isolate was sequenced with both, short-read Illumina and long-read Nanopore technologies and analysed in detail. This supported the hypothesis that the genome of this strain, ST6610-MRSA-IVg comprised of segments originating from two different clonal complexes (CC). While the backbone of the strain's genome, i.e., roughly 2 megabases, belongs to CC8, a continuous insert of 894 kb (approx. 30% of the genome) originated from CC140. Beside core genomic markers in the normal succession and orientation, this insert also included the mecA gene, coding for PbP2a and causing methicillin resistance, localised on an SCC mec IVg element. This particular SCC mec type was also previously observed in CC140 MRSA from African countries. A second conspicuous observation was the presence of the trimethoprim resistance gene dfrG within on a prophage that occupied an attachment site normally used by Panton-Valentine Leucocidin phages. This observation could indicate a role of large-scale chromosomal recombination in the evolution of S. aureus as well as a role of phages in the dissemination of antibiotic resistance genes. [ABSTRACT FROM AUTHOR]

Abstract Background Methicillin-resistant Staphylococcus aureus (MRSA) is spreading worldwide and poses a serious public health problem, being present in hospital settings and communities. However, from the Middle East and the Arabian Peninsula few molecular typing data on MRSA strains are currently available. In order to obtain data on the population structure of MRSA in Riyadh, Saudi Arabia, 107 clinical and environmental MRSA isolates were genotyped using a microarray-based assay. Results Five major MRSA strains from four clonal complexes were identified CC8/ST239-III (20.75%), PVL-positive as well as -negative CC22-IV (18.87% and 9.43%, respectively), PVL-positive CC30-IV (12.26%) and PVL-positive CC80-IV (17.92%). Minor strains, which accounted for less than 3% each, included CC1-IV/SCCfus, PVL-positive CC1/ST772-V, PVL-positive as well as- negative CC5-IV, CC5-IV/SCCfus, CC5-V, CC6-IV, CC45-IV, PVL-negative CC80-IV, PVL-positive CC88-IV, CC97-V and a CC9/ST834-MRSA strain. Conclusions Typing of MRSA strains from Riyadh revealed a high diversity of clonal complexes. The prevalence of the genes encoding the Panton-Valentine leukocidin was surprisingly high (54.21%), and a significant rate of resistance markers was detected also in strains considered as community-associated.

In order to obtain more information on the MRSA population structure in the border region of Afghanistan and Pakistan, we collected and genotyped MRSA causing bloodstream infections from a tertiary care hospital in Peshawar, Pakistan, that serves the local population as well as Afghan immigrants and refugees. Thirty-one MRSA isolates from 30 patients were included and characterized by microarray hybridisation. For 25 patients, serum samples were tested using protein microarrays in order to detect antibodies against staphylococcal virulence factors. The most conspicuous result was the high rate of PVL-positive MRSA. Twenty-two isolates (71%) harboured lukF/S-PV genes. The most common lineage was CC772-MRSA-V/VT (PVL+) to which eleven isolates were assigned. The second most common strain was, surprisingly, CC8-MRSA-[IV+ACME] (PVL+), "USA300" (9 isolates). Two isolates were tst1 positive CC22-MRSA-IV, matching the Middle Eastern "Gaza Epidemic Strain". Another two were PVL-positive CC30-MRSA-IV. The remaining isolates belonged to, possibly locally emerging, CC1, CC5, and CC8 strains with SCC mec IV elements. Twenty-three patient sera were positive for anti-PVL-IgG antibodies. Several questions arise from the present study. It can be assumed that MRSA and high rates of PVL-positive S. aureus/MRSA are a public health issue in the Afghanistan/Pakistan border region. A possible emergence of the "USA300" clone as well as of the CC772 lineage warrants further investigation. [ABSTRACT FROM AUTHOR]

This study looked at 227 saliva samples from Rhesus macaques (Macaca mulatta) and 218 samples from the surrounding environments. From these samples, MRSA isolates were collected from Rhesus saliva samples (n = 13) and environmental samples (n = 19) near temple areas in Kathmandu, Nepal. For comparison, selected MRSA isolates (n = 5) were obtained from patients with wound infections from a Kathmandu hospital. All isolates were characterized using Abbott StaphyType® DNA microarrays. Eighteen isolates (62%) from monkeys (n = 4; 31%) and environmental samples (n = 14; 74%), were CC22-MRSA-IV. Most (n = 16) of them carried both, the PVL locus and toxic shock toxin gene (tst1), an unusual combination which is the same as in previously characterized strain from Nepalese macaques and pigs. The five human isolates also belonged to that strain type. Eight monkey MRSA isolates were CC361-MRSA-IV. One MRSA from a monkey and one from an environmental sample, were CC88-MRSA-V. Other environmental MRSA included one each, CC121-MRSA-VT, and CC772 -MRSA-V. Two were CC779-MRSA-VT, potentially a novel clone. All MRSA carried the blaZ gene. The aacA–aphD , dfrA , and erm (C) genes were very common in isolates from all sources. One macaque MRSA carried the resistance genes aphA3 and sat , neither previously identified in primate MRSA isolates. This current study suggests that humans could be a potential source of the MRSA in the macaques/environment and transmission may be linked to humans feeding the primates and/or living in close proximity to each other. [ABSTRACT FROM AUTHOR]

Methicillin-resistant Staphylococcus aureus (MRSA) were identified in macaques, their environmental facility, and nasal cultures of personnel from the Washington National Primate Research Center [WaNPRC] and included MRSA ST188 SCC mec IV and MRSA ST3268 SCC mec V. The aim of the current study was to determine the carriage of virulence genes, antibiotic resistance genes, and other characteristics of the primate MRSA isolates to determine if there were any obvious differences that would account for differences in transmission within the WaNPRC facility. In total, 1,199 samples from primates were tested for the presence of MRSA resulting in 158 MRSA-positive samples. Fifteen ST188 isolates (all from Macaca nemestrina) and nine ST3268 (four from Macaca mulatta , two from Macaca fascicularis , three from M. nemestrina), were selected for further characterization. All but one of the 15 ST188 isolates had spa type t189 and the remaining one had spa type t3887. These isolates were resistant to β-lactams [ blaZ, mecA ], macrolides/lincosamides [ erm (B)], aminoglycosides [ aacA-aphD ], and fluoroquinolones. Five isolates were additionally resistant to tetracyclines [ tet (K)] and had elevated MICs for benzalkonium chloride [ qacC ]. In comparison, the nine ST3268 isolates had the related spa types t15469 (n = 5) and t13638 (n = 4). All nine ST3268 isolates were resistant to β-lactams [ blaZ, mecA ], and tetracyclines [ tet (K)]. Some isolates were additionally resistant to aminoglycosides [ aacA-aphD ], fluoroquinolones and/or showed elevated MICs for benzalkonium chloride [ qacC ]. In contrast to the ST188 isolates, the ST3268 isolates had the enterotoxin gene cluster egc [ seg, sei, selm, seln, selo, selu ] and enterotoxin genes sec and sel. The two clones have differences regarding their spa types, virulence and antibiotic resistance genes as well as ST and SCC mec types. However, the data presented does not provide insight into why ST188 spreads easily while ST3268 did not spread within the WaNPRC in-house primates. [ABSTRACT FROM AUTHOR]

ST239-MRSA-III is probably the oldest truly pandemic MRSA strain, circulating in many countries since the 1970s. It is still frequently isolated in some parts of the world although it has been replaced by other MRSA strains in, e.g., most of Europe. Previous genotyping work (Harris et al., 2010 ; Castillo-Ramírez et al., 2012 ) suggested a split in geographically defined clades. In the present study, a collection of 184 ST239-MRSA-III isolates, mainly from countries not covered by the previous studies were characterized using two DNA microarrays (i) targeting an extensive range of typing markers, virulence and resistance genes and (ii) a SCCmec subtyping array. Thirty additional isolates underwent whole-genome sequencing (WGS) and, together with published WGS data for 215 ST239-MRSA-III isolates, were analyzed using in-silico analysis for comparison with the microarray data and with special regard to variation within SCCmec elements. This permitted the assignment of isolates and sequences to 39 different SCCmec III subtypes, and to three major and several minor clades. One clade, characterized by the integration of a transposon into nsaB and by the loss of fnbB and splE was detected among isolates from Turkey, Romania and other Eastern European countries, Russia, Pakistan, and (mainly Northern) China. Another clade, harboring sasX/sesI is widespread in South-East Asia including China/Hong Kong, and surprisingly also in Trinidad & Tobago. A third, related, but sasX/sesI-negative clade occurs not only in Latin America but also in Russia and in the Middle East from where it apparently originated and from where it also was transferred to Ireland. Minor clades exist or existed in Western Europe and Greece, in Portugal, in Australia and New Zealand as well as in the Middle East. Isolates from countries where this strain is not epidemic (such as Germany) frequently are associated with foreign travel and/or hospitalization abroad. The wide dissemination of this strain and the fact that it was able to cause a hospital-borne pandemic that lasted nearly 50 years emphasizes the need for stringent infection prevention and control and admission screening. [ABSTRACT FROM AUTHOR]

The most common livestock-associated lineage of methicillin-resistant Staphylococcus aureus (MRSA) in Western Europe is currently clonal complex (CC) 398. CC398-MRSA spread extensively across livestock populations in several Western European countries, and livestock-derived CC398-MRSA strains can also be detected in humans. Based on their SCC mec elements, different CC398 strains can be distinguished. SCC mec elements of 100 veterinary and human CC398-MRSA isolates from Germany and Austria were examined using DNA microarray-based assays. In addition, 589 published SCC and/or genome sequences of CC398-MRSA (including both, fully finished and partially assembled sequences) were analysed by mapping them to the probe sequences of the microarrays. Several isolates and sequences showed an insertion of a large fragment of CC9 genomic DNA into the CC398 chromosome. Fifteen subtypes of SCC mec elements were detected among the 100 CC398 isolates and 41 subtypes could be discerned among the published CC398 sequences. Eleven of these were also experimentally detected within our strain collection, while four subtypes identified in the isolates where not found among the sequences. A high prevalence of heavy metal resistance genes, especially of czrC , was observed among CC398-MRSA. A possible co-selection of resistances to antibiotics and zinc/copper supplements in animal feed as well as a spill-over of SCC mec elements that have evolved in CC398-MRSA to other, possibly more virulent and/or medically relevant S. aureus lineages might pose public health problems in future. [ABSTRACT FROM AUTHOR]

Purpose: Methicillin resistant Staphylococcus aureus CC15 strains (CC15-MRSA) have only been sporadically described in literature. This study was carried out to describe the genetic make-up for this rare MRSA strain. Methods: Four CC15-MRSA isolates collected in Riyadh, Saudi Arabia, between 2013 and 2014 were studied. Two isolates were from clinical infection and 2 from retail meat products. Whole genome sequencing was carried out using Illumina HiSeq2500 genome analyzer. Results: All the CC15-MRSA isolates had the multilocus sequence typing profile ST1535, 13-13-1-1-81-11-13, which is a single locus variant of ST15. Of the 6 contigs related to the SCC element, one comprised a recombinase gene ccrAA, ccrC-PM1, fusC and a helicase, another one included mvaS, dru, mecA and 1 had yobV and Q4LAG7. The SCC element had 5 transposase genes, namely 3 identical paralogs of tnpIS431 and 2 identical paralogs of tnpIS256. Two identical copies of a tnpIS256-based insertion element flank the aacA-aphD gene. Two copies of this insertion element were present with 1 located in the SCC element and another inserted into the sasC gene. A short 3 kb region, which lacks any bacteriophage structural genes and site-specific DNA integrase, was inserted into the hlb gene. The hsdM and the 5'-part of the hsdS gene are replaced by a copy of the hsdM/hsdS paralogs from nSab giving rise to a new chimeric paralog of hsdS in nSaa. Conclusion: CC15-MRSA shows a novel SCCmecV/SCCfus composite element. Its variant of hsdM/hsdS probably facilitated uptake of foreign mobile genetic elements that promoted emergence of CC15-MRSA. Close surveillance is needed to monitor spread and emergence of further CC15 MRSA strains. [ABSTRACT FROM AUTHOR]

Summary Staphylococcus aureus continues to pose major public health challenges in many areas because of antibiotic resistance problems. In the Caribbean, especially Trinidad and Tobago, the challenge is not different. This study was performed to evaluate the antimicrobial resistance gene prevalence among S. aureus isolates in Trinidad and Tobago. Standard and molecular microbiological methods, including the Microscan automated system, DNA microarray and multi locus sequence typing (MLST) analysis, were performed on 309 clinical S. aureus isolates recovered from patients who were treated at three of the country's main health institutions. S. aureus exhibited susceptibilities ≥80% to eleven of the 19 antimicrobials tested against it, and these belong to the most commonly used and available antibiotics in the country. While the antibiotic to which it was most susceptible of the commonly used antibiotics was trimethoprim/sulfamethoxazole, the antibiotics to which it was least susceptible or most resistant to were ampicillin and penicillin. S. aureus isolates from the pediatric ward produced the greatest rate of susceptibility among the isolates recovered from patients admitted into hospitals, while isolates from Accident and Emergency rooms displayed the greatest susceptibilities among patients from the community. S. aureus isolates from the country did not harbor acquired resistant genes targeting clindamycin/macrolides ( erm B), linezolid ( cfr ) or vancomycin ( van A). The bla Z gene, which is the most common beta lactam (Penicillinase) resistance mechanism for S. aureus , was observed in 88.7% of the methicillin susceptible S. aureus , while methicillin resistance mediated by the mec gene was present in 13.6%. Most of the resistance markers found in MRSA isolates were significantly associated with the ST239-MRSA-III strain in this study, and all isolates that belonged to the USA300 strain, which additionally encoded both the PVL gene and ACME cluster, belonged to CC8. Several resistant genes, such as van A, cfr and erm B, mediating resistance in S. aureus , are currently non-existent in Trinidad and Tobago. However, the majority of SCC mec genes were observed, suggesting that there is ongoing nosocomial transmission with minimal community transmission. This calls for stringent antibiotic stewardship and policies in the country. [ABSTRACT FROM AUTHOR]

Methicillin-resistant Staphylococcus aureus (MRSA) is a major human health problem and recently, domestic animals are described as carriers and possible reservoirs. Twenty seven S. aureus isolates from five turkey farms (n = 18) and two broiler farms (n = 9) were obtained by culturing of choana and skin swabs from apparently healthy birds, identified by Taqman-based real-time duplex nuc-mecA-PCR and characterized by spa typing as well as by a DNA microarray based assay which covered, amongst others, a considerable number of antibiotic resistance genes, species controls, and virulence markers. The antimicrobial susceptibility profiles were tested by agar diffusion assays and genotypically confirmed by the microarray. Five different spa types (3 in turkeys and 2 in broilers) were detected. The majority of MRSA isolates (24/27) belonged to clonal complex 398-MRSA-V. The most frequently occurring spa types were accordingly t011, t034, and t899. A single CC5-MRSA-III isolated from turkey and CC398-MRSA with an unidentified/truncated SCCmec element in turkey and broiler were additionally detected. The phenotypic antimicrobial resistance profiles of S. aureus isolated from both turkeys and broilers against 14 different antimicrobials showed that all isolates were resistant to ampicillin, cefoxitin, oxacillin, doxycycline, and tetracycline. Moreover, all S. aureus isolated from broilers were resistant to erythromycin and azithromycin. All isolates were susceptible to gentamicin, chloramphenicol, sulphonamides, and fusidic acid. The resistance rate against ciprofloxacin was 55.6% in broiler isolates and 42.1% in turkey isolates. All tetracycline resistant isolates possessed genes tetK/M. All erythromycin-resistant broiler isolates carried ermA. Only one broiler isolate (11.1%) carried genes ermA, ermB, and ermC, while 55.6% of turkey isolates possessed ermA and ermB genes. Neither PVL genes (lukF/S-PV), animal-associated leukocidin (lukM and luk-P83) nor the gene encoding the toxic shock syndrome toxin (tst1) were found in turkey and broiler isolates. In conclusion, the detection of MRSA in healthy turkeys and broilers with even additional antibiotic resistance markers is of major public health concern. The difference in antibiotic resistance and virulence markers between MRSA isolates from turkeys and broilers was addressed. [ABSTRACT FROM AUTHOR]

Our aim was to assess national prescribing trends and determine longitudinal resistance patterns for topical antimicrobials in New Zealand. We observed a dramatic increase in fusidic acid (FA) resistance, and clonal expansion of FA-resistant Staphylococcus aureus. This increase was concurrent with a significant national increase in topical FA dispensing. [ABSTRACT FROM PUBLISHER]

Norway is a country in which the Methicillin-resistant Staphylococcus aureus (MRSA) prevalence has been low for the last decades. There are virtually no epidemic, hospital-acquired MRSA because of an emphasis on strict infection control rules and restrictive use of antibiotics. However, community-acquired and/or Panton-Valentine leucocidin ( PVL)-positive MRSA need to be monitored as these strains are transmitted outside of healthcare facilities and cannot be contained by healthcare-centred strategies. All 179 non-repetitive isolates of PVL-positive MRSA that were received during 2011 at the regional infection control laboratory at Akershus University Hospital were preserved and spa typed. Seventy isolates were further characterized by DNA microarray hybridization. The most common PVL- MRSA lineages were ST8- MRSA- IV and CC30- MRSA- IV. Further common clones were CC80- MRSA- IV and CC5- MRSA- IV. Other clones were found sporadically. These included ST772- MRSA-V and ST834- MRSA- IV, the latter in patients with epidemiological connections to the Philippines. Small-scale family outbreaks affecting at least 49 individuals were noted, with numbers of known cases per outbreak ranging from two to seven. At least 24 cases were related to foreign travel to Eritrea, India, Iraq, Macedonia, Pakistan, the Philippines, Poland, Singapore, Turkey, the USA and Vietnam. These data show that community-acquired/ PVL-positive MRSA are not yet a major public health problem in Southern Norway. Our study corroborates the current practice of mandatory screening of patients and staff with travel histories, admissions or employment in healthcare institutions outside the Scandinavian countries or with known MRSA contacts. [ABSTRACT FROM AUTHOR]

• We describe the genotypic characteristics of S. aureus isolates among healthy dairy animals and their caretakers using DNA-microarray. • Nine different clonal lineages of MRSA and six clonal lineages of MSSA were inferred. • The study demonstrated, for the first time in Egypt, a high clonal diversity of S. aureus clones including MRSA (CC152, CC30, CC121, CC15, CC97) and MSSA types (CC361 and CC1278). • The missing of lukM/lukF-P83 gene in the recovered isolates indicated a human origin for a great majority of the isolates • The majority of S. aureus isolates presented a worrying antimicrobial resistance pattern. The purpose of this study was to describe the clonal diversity of Staphylococcus aureus strains derived from healthy dairy cattle and buffaloes as well as their close contact caretakers from the Nile Delta region, Egypt during 2019 and 2020, and to determine their antimicrobial resistance genotypes and virulence determinants. The study included 360 samples (120 from each, dairy cattle, buffaloes and their contact caretakers) collected from eight smallholding dairy herds.The samples included udder skin swabs, composite milk samples and rectal swabs (40 samples each of bovines) and nasal swabs, hand swabs and stool specimens (40 samples each of caretakers). S. aureus were isolated by classical techniques and characterised using the DNA microarray technology. A total of 62 methicillin-resistant (MRSA) and 130 methicillin-sensitive (MSSA) S. aureus isolates were identified. MRSA carriage rate ranged between 2.5% - 15% (Mean: 10%) in dairy cattle, 5% - 15% (9.2%) in dairy buffaloes and 27.5% - 37.5% (30.8%) among the caretakers. Nine different clonal lineages of MRSA (including CC22, CC152, CC5, CC30, CC88, CC45, CC121, CC97, and CC15), and six clonal lineages of MSSA (CC97, CC50, CC188, CC361, CC15 and CC1278) were inferred. The study demonstrated, for the first time, a high clonal diversity of multi-drug resistant S. aureus clones (particularly CC152-MRSA-V, CC30-MRSA-IV, CC121-MRSA-V, CC15-MRSA-V, CC97-MRSA-PseudoSCC mec , CC361-MSSA and CC1278-MSSA) which colonise dairy cattle and buffaloes as well as their caretakers particularly in Damietta villages that located at the northern Mediterranean coast of Egypt. The findings highlight the potential dynamics of humans and animals' S. aureus strains which may represent a health threat for both populations. The complete absence of the lukM/lukF-P83 genes in the recovered isolates indicated that all recovered cattle isolates (except for CC97) were descendants of human lineages and that these replaced the original cow lineages. Hence, a recommendation was given to farm owners to review their hygiene regimen to help minimize the microbiological risks for both populations. [ABSTRACT FROM AUTHOR]

Abstract: To gain insight into the genomic diversity of Staphylococcus aureus associated with diseases in domestic poultry, 131 isolates from clinically ill turkeys (n =80) and chickens (n =51) were collected and genotyped using microarray hybridisations. MRSA isolates were subjected to spa and dru typing and their antimicrobial resistance geno- and phenotypes were determined. Most (68 out of 80) turkey isolates belonged to the clonal complex (CC) 398. Seventeen of the 80 isolates (21.2%) were MRSA. The most common MRSA type among turkeys was CC398-MRSA-V (n =8), but CC5-MRSA-III (n =4), CC9-MRSA-IV (n =2), CC398-MRSA-IV (n =2) and a single CC398-MRSA with an unidentified/truncated SCCmec element were also found. Among the chicken isolates, CC5 predominated (44 out of 51). Five of the chicken isolates were MRSA (9.8%), all belonging to CC398-MRSA-V. These data show that the current dissemination of livestock-associated MRSA also engulfs chickens and turkeys, and that MRSA surveillance among these species is warranted. [Copyright &y& Elsevier]

Abstract: The recently described phenol-soluble modulin PSM-mec was detected in Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus fleuretti, Staphylococcus hominis, Staphylococcus pseudintermedius, Staphylococcus saprophyticus, Staphylococcus simulans and Staphylococcus vitulinus from different hosts (humans, goats, dogs, cats, pigs, cattle and turkeys). It was identified in isolates harbouring SCCmec types II, IIA, IIB, IID, III, VIII and in some irregular or truncated elements. [Copyright &y& Elsevier]

Objectives: Fifty-four methicillin-resistant Staphylococcus aureus (MRSA) ST398 isolates from unrelated diseased swine collected all over Germany were comparatively investigated for their antimicrobial resistance and virulence properties, and for their genomic relatedness. [ABSTRACT FROM PUBLISHER]

Abstract: Staphylococcus aureus is a common pathogen which can colonise and infect not only man, but also domestic animals. Especially, infection of cattle is of high economic relevance as S. aureus is an important causal agent of bovine mastitis. In the present contribution, a DNA microarray was applied for the study of 144 different gene targets, including resistance genes and genes encoding exotoxins, in S. aureus isolated from cows. One hundred and twenty-eight isolates from Germany and Switzerland were tested. These isolates were assigned to 20 different strains and nine clonal complexes. The majority of isolates belonged either to apparently closely related clonal complexes 8, 25, and 97 (together 34.4%) or were related to the sequenced bovine strain RF122 (48.4%). Notable characteristics of S. aureus of bovine origin are the carriage of intact haemolysin beta (in 82% of isolates tested), the absence of staphylokinase (in 89.1%), the presence of allelic variants of several exotoxins such as toxic shock syndrome toxin and enterotoxin N, and the occurrence of the leukocidin lukF-P83/lukM (in 53.1%). Two isolates were methicillin-resistant S. aureus (MRSA). One of them was a clonal complex 8 MRSA related to the epidemic MRSA strain Irish 01. The other one belonged to ST398/spa-type 34 resembling a newly emerging MRSA strain which has been described to occur in humans as well as in domestic animals. The presence of these two strains highlights the possibility of transfers of S. aureus strains between different host species. [Copyright &y& Elsevier]

The article focuses on a study which investigated the genotypic relationships of spectinomycin-resistant and pleuromutilin-resistant strains of methicillin-resistant Staphylococcus aureus (MRSA). It described the characteristics of two types of enterococcal-like multi-resistance gene clusters in S. aureus. Topics covered include methods used in the study and characteristics of the MRSA strains used in the study.

Due to the rapid spread of antibiotic resistance, and the difficulties of treating biofilm-associated infections, alternative treatments for S. aureus infections are urgently needed. We tested the lytic activity of several wild type phages against a panel of 110 S. aureus strains (MRSA/MSSA) composed to reflect the prevalence of S. aureus clonal complexes in human infections. The plaquing host ranges (PHR) of the wild type phages were in the range of 51% to 60%. We also measured what we called the kinetic host range (KHR), i.e., the percentage of strains for which growth in suspension was suppressed for 24 h. The KHR of the wild type phages ranged from 2% to 49%, substantially lower than the PHRs. To improve the KHR and other key pharmaceutical properties, we bred the phages by mixing and propagating cocktails on a subset of S. aureus strains. These bred phages, which we termed evolution-squared (ε2) phages, have broader KHRs up to 64% and increased virulence compared to the ancestors. The ε2-phages with the broadest KHR have genomes intercrossed from up to three different ancestors. We composed a cocktail of three ε2-phages with an overall KHR of 92% and PHR of 96% on 110 S. aureus strains and called it PM-399. PM-399 has a lower propensity to resistance formation than the standard of care antibiotics vancomycin, rifampicin, or their combination, and no resistance was observed in laboratory settings (detection limit: 1 cell in 1011). In summary, ε2-phages and, in particular PM-399, are promising candidates for an alternative treatment of S. aureus infections. [ABSTRACT FROM AUTHOR]

• 90 MRSA isolates from companion animals were examined using DNA microarray based assays and whole-genome sequencing. • Eight sequence types (STs - ST398, ST5275 (new ST), ST225, ST8, ST22, ST152, ST1, and ST45) were detected. • Although ST398 isolates remained predominant, increasing isolation rates of human-associated MRSA clones were observed in cats and dogs. The aim of the present study was to investigate the diversity of methicillin-resistant Staphylococcus aureus (MRSA) that originated from Austrian companion animals during the last five-year period. A total of 90 non-repetitive MRSA isolates were obtained during diagnostic activities from autumn 2013 to autumn 2018. They originated from horses (n = 62), cats (n = 13), dogs (n = 10), rabbits (n = 2), a domestic canary, a zoo-kept hammer-headed bat (Hypsignathus monstrosus) and a semi-captive northern bald ibis (Geronticus eremita). Antimicrobial susceptibility testing was performed. All isolates were mecA -positive and mecC -negative. The isolates were genotyped by SCC mec, spa and dru typing, Multiple-Locus Variable number of tandem repeat Analyses (MLVA), S. aureus DNA microarray, and whole-genome sequencing (WGS). Eight sequence types (STs - ST398, ST5275 (new ST), ST225, ST8, ST22, ST152, ST1, and ST45), three SCC mec types (II, IV, and V), sixteen spa types (t003, t008, t011, t015, t032, t034, t1381, t1928, t1985, t223, t334, t355, t430, t6447, t6867, and t7105), fourteen dru types (dt10a, dt10az, dt10q, dt10r, dt11a, dt5e, dt6j, dt9a, dt9ak, dt9g, and four new types dt8as, dt7ak, dt4j, dt14n), and thirty-five MLVA types were detected. WGS-based core genome MLST (cgMLST) displayed five main clusters. Compared to the time period 2004–2013, the results of the present study show not only a higher diversity among the MRSA isolates within the population of Austrian companion animals, but also the introduction of new clones. Although ST398 isolates remained predominant, mainly due to high presence of this lineage among horses, increasing isolation rates of human-associated MRSA clones were observed in cats and dogs. [ABSTRACT FROM AUTHOR]

Introduction: Healthcare workers (HCWs) colonized with Staphylococcus aureus may serve as a reservoir of infection. This study was carried to determine the genetic make-up of S. aureus nasal colonizers in HCWs. Methodology: Nasal swabs were obtained from 93 HCWs and molecular characterization of identified S. aureus isolates was carried out using the StaphyType DNA microarray (Alere Technologies GmbH, Jena, Germany). Results: Twenty-nine HCWs (31%) were colonized with S. aureus (MSSA = 23; MRSA = 6). Thus the overall MRSA carriage rate was 6.5% (n/N = 6/93) and 20.7% (n/N = 6/29) of those colonized with S. aureus harboured MRSA. The S. aureus isolates belonged to 16 clonal complexes (CC). MSSA isolates included three each for CC15, CC188, ST2867; two each for CC5, CC97, CC367 as well as one each for CC1, CC8, CC30, CC45, CC101, CC121, ST291/813 and CC1153. The staphylococcal cassette chromosome recombinase genes ccrA-1; ccrB-1 and the fusidic acid resistance gene (fusC) were present in two MSSA isolates (CC1 and CC8). The six MRSA isolates included CC5-MRSA- [VI+fusC] (n = 2); one each of CC5-MRSA-V; CC22-MRSA-IV (tst1+); CC80-MRSA-IV [pvl+] ("European CA-MRSA Clone") and CC97- MRSA-[V+fusC]. Conclusion: There is wide clonal diversity of S. aureus colonizers with associated high MRSA carriage among the HCWs. The presence of genetically stable MSSA isolates with the capability to transform into MRSA isolates is of concern. [ABSTRACT FROM AUTHOR]

Summary Objectives CC22-MRSA-IV, UK-EMRSA-15/Barnim EMRSA, is a common and pandemic strain of methicillin-resistant Staphylococcus aureus (MRSA) that has been found mainly in Western Europe, but also in other parts of the world including some Gulf countries. One suspected case of an infection with this strain in a patient who was admitted to the surgical unit in Riyadh, Kingdom of Saudi Arabia (KSA) was investigated in order to check whether this strain has reached KSA. Methods Besides the index isolate, 46 additional isolates of CC22-MRSA-IV from patients from KSA, Abu Dhabi, Kuwait, and Germany (patients with a history of travel in the Middle East), were characterized by microarray hybridization. Results The study revealed a regional presence of as many as six distinct ‘strains’ of CC22-MRSA-IV that could be distinguished based on carriage of SCC mec IV subtypes and virulence factors. No true UK-EMRSA-15/Barnim EMRSA was identified in Riyadh; all suspected isolates from Riyadh were assigned to other, albeit related strains. However, this strain was identified in Abu Dhabi and Kuwait. Conclusions CC22-MRSA-IV from KSA could be linked to other epidemic strains from the Middle East and possibly India, rather than to the Western European UK-EMRSA-15/Barnim EMRSA. High-resolution typing methods, including SCC mec subtyping, might help to differentiate related epidemic strains and to monitor routes of transmission. [ABSTRACT FROM AUTHOR]