Sequencing a CC239-MRSA-III with a novel composite SCC mec element from Kuwait.

Staphylococcus aureus CC239-MRSA-III is an ancient pandemic strain of hospital-associated, methicillin-resistant S. aureus that spread globally for decades and that still can be found in some parts of the world. In Kuwait, microarray-based surveillance identified from 2019 to 2022 a series of isolates of a hitherto unknown variant of this strain that carried a second set of recombinase genes, ccrA/B-2. To elucidate the structure of its SCCmec element, two isolates were subjected to nanopore sequencing. This revealed, in addition to ccrA/B-2, several SCC-associated genes including speG (spermidine N acetyltransferase) and a gene encoding a large "E-domain containing protein" (dubbed as edcP-SCC). This gene contained three regions consisting of multiple repeating units. In terms of sequence and structure it was similar but not identical to the biofilm-related aap gene from S. epidermidis. A review of published sequences identified edcP-SCC in eighteen genome sequences of S. aureus, S. epidermidis and S. capitis, and frequently it appears in a similar cluster of genes as in the strains sequenced herein. Isolates also carried a prophage with the adhesion factor sasX/sesI and aminoglycoside resistance genes. This is consistent with an affiliation to the "South-East Asian" Clade of CC239. The emergence of edcP-SCC and sasX-positive CC239 strain shows that, against a global trend towards community-associated MRSA, the ancient pandemic CC239 hospital strain still continues to evolve and to cause outbreaks.

Description of Methicillin-Susceptible Staphylococcus aureus Clonal Complex 30 Related to the Pandemic Phage Type 80/81 Isolated from Patients in Three Tertiary Hospitals in Jos, North Central Nigeria.

OBJECTIVE: The prevalence of phage 80/81 Staphylococcus aureus strains, the pandemic strains that were dominant in the 1950s, had declined in the 1960s and 1970s. However, these strains have reemerged in some countries in recent years. This study investigated the antibacterial resistance, virulence, and the genetic backgrounds of CC30-MSSA isolates obtained from patients in three tertiary hospitals. MATERIALS AND METHODS: Twenty-two CC30-MSSA isolates cultured from different clinical samples were investigated using antibiotic sensitivity testing, spa typing, multilocus sequence typing, and DNA microarray analysis. RESULTS: All 22 isolates were susceptible to vancomycin (MIC ≤2 µg/mL), teicoplanin (MIC ≤2 µg/mL), and cefoxitin but were resistant to penicillin G (n = 22; 100.0%), tetracycline (n = 12; 54.5%), ciprofloxacin (n = 15; 68.2%), cadmium acetate (n = 22; 100%), mercuric chloride (n = 13; 59.1%), and ethidium bromide (n = 3; 13.6%). The isolates belonged to sequence type, ST30, and five spa types: t012 (n = 12; 54.5%), t019 (n = 5; 22.7%), t017 (n = 2; 9.1%), t037 (n = 2; 9.1%), and t318 (n = 1; 4.5%). All 22 isolates were positive for agrIII, cap8, clfA, clfB, icaA, icaC, icaD, cna, and staphylococcal enterotoxin gene clusters (seg, sei, sem, sen, seo, seu). Eight isolates carried lukS-PV and lukF-PV that code for Panton-Valentine leukocidin. CONCLUSION: The current CC30-MSSA isolates share phenotypic and genotypic characteristics with the pandemic phage 80/81 isolates that were common in the 1950s and 1960s. Continued surveillance is recommended to keep abreast of the changing epidemiology of S. aureus causing healthcare and community-associated infections.

Fusidic Acid Resistance Determinants in Methicillin-Resistant Staphylococcus aureus Isolated in Kuwait Hospitals.

OBJECTIVE: The aim of this study was to investigate the genetic determinants of fusidic acid (FA) resistance in MRSA isolated from patients in Kuwait hospitals. METHODS: The minimum inhibitory concentration (MIC) of FA was tested with E-test strips. Genetic determinants of FA were determined by PCR and DNA microarray. Staphylococcal protein A gene (spa) typing and DNA microarray analysis were used to study their genetic backgrounds. RESULTS: The FA MIC ranged from 2 mg/L to >256 mg/L. Of the 97 isolates, 79 (81.4%) harbored fusC, 14 isolates harbored fusA mutations (fusA), and 4 isolates harbored fusB. Isolates with fusA mutations expressed high FA MIC (MIC >256 mg/L), whereas those with fusC and fusB expressed low FA MIC (MIC 2-16 mg/L). The isolates belonged to 23 spa types and 12 clonal complexes (CCs). The major spa types were t688 (n = 25), t311 (n = 14), t860 (n = 8), and t127 (n = 6) which constituted 54.6% of the isolates. The 12 CCs were CC1, CC5, CC8, CC15, CC22, CC80, CC88, and CC97 with CC5 (45.6%) and CC97 (13.2%) as the dominant CCs. CONCLUSIONS: The MRSA isolates belonged to diverse genetic backgrounds with the majority carrying the fusC resistance determinants. The high prevalence of FA resistance belonging to diverse genetic backgrounds warrants a review of FA usage in the country to preserve its therapeutic benefits.

Antibiotic resistance and typing of the methicillin-resistant Staphylococcus aureus clones in Kuwait hospitals, 2016-2017.

BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) belong to diverse genetic backgrounds that differ in antibiotic resistance. Knowledge of the local clonal composition of MRSA strains is important for patients' management and for designing effective control and eradication methods. The aim of this study was to compare the antibiotic resistance patterns and genotypic characteristics of MRSA isolates obtained in public hospitals in Kuwait in 2016 and 2017 for changes in their resistance patterns and clonal composition. METHODS: A total of 4726 MRSA isolates obtained in 2016-2017 from clinical specimens in Kuwait public hospitals were characterized using antibiogram, SCCmec typing, spa typing and DNA microarray. RESULTS: The isolates expressed resistance to fusidic acid (52.9%), kanamycin (41.6%), gentamicin (32.5%) and erythromycin (36.2%). The prevalence of high-level mupirocin resistance decreased from 3.7% in 2016 to 2.4% in 2017, while the proportion of resistance to other antibiotics remained relatively stable. A total of 382 spa types were detected with eight spa types, t688 (N = 547), t304 (N = 428), t860 (N = 394), t127 (N = 306), t044 (N = 230), t311 (N = 243), t223 (N = 184) and t002 (N = 181) constituting 53.1% of the MRSA isolates in 2016-2017. Of the 3004 MRSA isolates obtained in 2016 (N = 1327) and 2017 (N = 1677) selected for DNA microarray analysis, 26 clonal complexes (CCs) were identified. Most of the isolates belonged to CC1 (N = 248), CC5 (N = 833), CC6 (N = 241), CC8 (N = 292), CC22 (N = 421), CC30 (N = 177), CC80 (N = 177) and CC97 (N = 171). The prevalence of CC5 isolates has significantly (p ≤ 0.05) increased from 294 isolates in 2016 to 539 isolates in 2017. Although CC22 increased from 196 isolates in 2016 to 225 isolates in 2017, CC1 increased from 112 isolates in 2016 to 136 isolates in 2017, CC6 increased from 103 isolates in 2016 to 138 isolates in 2017, these changes were not significant (p ≥ 0.05). CONCLUSION: These results revealed the diversity in the genetic backgrounds of MRSA isolates and the stable maintenance of the dominant MRSA clones in Kuwait hospitals in 2016 and 2017 suggesting an on-going transmission of these clones. Novel and creative infection prevention and control measures are required to curtail further transmission.

Genetic diversity of methicillin resistant Staphylococcus aureus strains isolated from burn patients in Iran: ST239-SCCmec III/t037 emerges as the major clone.

Methicillin-resistant Staphylococcus aureus (MRSA) as a major cause of infection in health care, hospital and community settings is a global health concern. The purpose of this study was to determine the antibiotic susceptibility pattern and distribution of circulating molecular types of MRSA in a burn hospital in Tehran, the capital of Iran. During a 10-month study period, 106 Staphylococcus aureus isolates were assessed. Isolates were subjected to susceptibility testing using the disk diffusion method and Polymerase Chain Reaction (PCR) for detection of mecA, fem and nuc genes. The presence of PVL and tst encoding genes were determined by PCR method. All the MRSA isolates were genotyped by multilocus sequence typing (MLST), spa typing, SCCmec typing and agr typing. The presence of mecA gene was confirmed in all the Staphylococcus aureus isolates. Antimicrobial susceptibility testing revealed a high resistance rate (90.6%) to ampicillin, tetracycline, and erythromycin. The rates of resistance to remaining antibiotics tested varied between 18.9% and 84.9%. The high- level of resistance to mupirocin was confirmed in 19.8% of MRSA strains isolated from burn patients. Multi-drug resistance was observed in 90.6% of isolates. Sixteen of the 106 MRSA isolates (15.1%) harbored PVL-encoding genes. The majority of our MRSA strains carried SCCmec III (71.7%). ST239-SCCmec III/t037 (34%) was the most common genotype followed by ST239-SCCmec III/t030 (24.5%), ST15-SCCmec IV/t084 (15.1%), ST22-SCCmec IV/t790 (13.2%), and ST239-SCCmec III/t631 (13.2%). Mupirocin resistant MRSA isolates belonged to ST15-SCCmec IV/t084 (40%), ST22-SCCmec IV/t790 (23.3%), ST239-SCCmec III/t631 (20%), and ST239-SCCmec III/t030 (16.7%) clones. The results showed that genetically diverse strains of MRSA are circulating in our burn hospitals with relatively high prevalence of ST239-SCCmec III/t037 clone. The findings support the need for regular surveillance of MRSA to determine the distribution of existing MRSA clones and to detect the emergence of new MRSA clones.

Genetic Lineages of Methicillin-Resistant Staphylococcus aureus Acquired during Admission to an Intensive Care Unit of a General Hospital.

OBJECTIVES: The objectives of this study were to determine the frequency of methicillin-resistant Staphylococcus aureus (MRSA) colonization or infection while on admission to the intensive care unit (ICU), and examine the genetic backgrounds of the MRSA isolates to establish transmission among the patients. SUBJECTS AND METHODS: This study involved screening 2,429 patients admitted to the ICU of Farwania Hospital from January 2005 to October 2007 for MRSA colonization or infection. The MRSA isolates acquired after admission were investigated using a combination of molecular typing techniques to determine their genetic backgrounds. RESULTS: Of 2,429 patients screened, 25 (1.0%) acquired MRSA after admission to the ICU. Of the 25 MRSA, 19 (76%) isolates belonged to health care-associated (HA-MRSA) clones: ST239-III (n = 17, 68%) and ST22-IV (n = 2, 8%). The remaining 6 MRSA isolates belonged to community-associated clones: ST80-IV (n = 3, 12%), ST97-IV (n = 2, 8%), and ST5-IV (n = 1, 4%). The ST239-III-MRSA clone was associated with infection as well as colonization, and was isolated from patients from 2005 to 2007. CONCLUSIONS: The HA-MRSA clone ST239-III persistently colonized patients admitted to the ICU, indicating the possibility of its transmission among the patients over time.

Antibiotic Resistance Trends in Methicillin-Resistant Staphylococcus aureus Isolated in Kuwait Hospitals: 2011-2015.

OBJECTIVE: The aim of this study was to determine antibiotic resistance trends and carriage of staphylococcal cassette chromosome mec (SCCmec) genetic elements in methicillin-resistant Staphylococcus aureus (MRSA) isolated in Kuwait hospitals to ascertain whether they were healthcare associated (HA-MRSA) or community associated (CA-MRSA). MATERIALS AND METHODS: In total, 6,922 MRSA isolates obtained from different clinical samples were tested for resistance to antibiotics, urease production, and carriage of SCCmec elements. RESULTS: All MRSA isolates were susceptible to linezolid, vancomycin, and teicoplanin. However, some isolates were resistant to kanamycin (2,979; 43%), ciprofloxacin (2,955; 42.7%), erythromycin and clindamycin (2,935; 42.4%), fusidic acid (2,858; 41.2%), gentamicin (2,665; 38.5%), tetracycline (2,652; 38.3%), and trimethoprim (2,324; 33.5%). Whereas the prevalence of resistance to most antibiotics showed annual variations, those resistant to chloramphenicol and rifampicin increased from 2.6 and 0.1% to 9.6 and 1.6%, respectively, and high-level mupirocin resistance declined from 9.3% in 2011 to 3.6% in 2015. In total, 3,244 (53.9%) of the isolates carried SCCmec IV followed by SCCmec III (1,737; 28.8%) and SCCmec V (890; 14.8%). SCCmec I (21; 0.3%) and II (79; 0.8%) occurred sporadically. A total of 3,651 (60.7%) of the isolates belonged to the CA-MRSA genotype and 2,290 isolates (38.1%) were identified as HA-MRSA. CONCLUSION: This study demonstrates changes in antibiotic resistance patterns of MRSA over time and reinforces the value of surveillance in detecting such changes for the benefit of infection control and patient management.

Isolation of Salmonella enterica serovar Kentucky strain ST 198 and its H2S-negative variant from a patient: implications for diagnosis.

H2S-producing multiresistant Salmonella enterica serovar Kentucky strain sequence type (ST) 198 and its non-H2S-producing variant were isolated from a patient. Whole-genome comparison showed a base addition in the gene encoding molybdenum cofactor biosynthesis protein C, which could affect H2S production in the variant. Lack of H2S production has implications for diagnosis of salmonella.

Genomic profiling of methicillin-sensitive Staphylococcus aureus (MSSA) isolates in Kuwait hospitals.

Background: Staphylococcus aureus is an important pathogen that causes mild to invasive infections in hospitals and the community. Although methicillin-susceptible Staphylococcus aureus (MSSA) isolates continue to cause different infections, there is no data on the genetic backgrounds of the MSSA colonizing or causing infections in Kuwait hospitals. This study aimed to investigate MSSA isolated from patients admitted to Kuwait hospitals for antibiotic resistance and genetic backgrounds to understand their clonal composition. Methods: Consecutive MSSA isolates were collected from single patients during two surveillance periods in 2016 and 2021 in 13 public hospitals. The isolates were characterized using antibiogram, staphylococcal protein A (spa) typing, DNA microarray analysis, and multilocus sequence typing (MLST) using standard protocols. Results: A total of 446 MSSA was cultured from different clinical samples in 2016 (n = 240) and 2021 (n = 206). All isolates were susceptible to vancomycin [minimum inhibitory concentration (MIC) ≤ 2 mg/L], teicoplanin (MIC ≤2 mg/L), linezolid (MIC ≤4 mg/L), ceftaroline (MIC ≤2 mg/L), rifampicin, and mupirocin but were resistant to erythromycin (21.3%), clindamycin (14.0%), gentamicin (3.8%), kanamycin (10.5%), fusidic acid (27.0%), tetracycline (6.9%), trimethoprim (23.1%), and ciprofloxacin (35.2%). Molecular typing identified 155 spa types, dominated by t127 (15.0%), t084 (5.4%), t3841 (5.4%), t267 (2.4%), t442 (2.2%), t091 (2.2%), t021 (2.2%), and t003 (2.2%); 31 clonal complexes (CCs); and 56 sequence types (STs). The majority of the isolates (n = 265; 59.4%) belonged to CC1 (20.6%), CC15 (10.9%), CC22 (5.1%), CC30 (7.6%), CC361 (10.1%), and CC398 (4.7%). Discussion: The MSSA isolates belonged to diverse genetic backgrounds dominated by CC1, CC15, CC22, CC30, CC361, and CC398. The distribution of MSSA clones in 2016 and 2021 showed the stability of these clones over time. The study provides the first comprehensive data on the clonal distribution of MSSA in Kuwait hospitals.

Community-acquired methicillin-resistant Staphylococcus aureus: the new face of an old foe?

The burden of infections caused by community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) is increasing among different patient populations globally. As CA-MRSA has become established in healthcare facilities, the range of infections caused by them has also increased. Molecular characterization of CA-MRSA isolates obtained from different centers has revealed significant diversity in their genetic backgrounds. Although many CA-MRSA strains are still susceptible to non-ß-lactam antibiotics, multiresistance to non-ß-lactam agents has emerged in some clones, posing substantial problems for empirical and directed therapy of infections caused by these strains. Some CA-MRSA clones have acquired the capacity to spread locally and internationally. CA-MRSA belonging to ST80-MRSA-IV and ST30-MRSA-IV appear to be the dominant clones in the countries of the Gulf Cooperation Council (GCC). The emergence of pandemic CA-MRSA clones not only limits therapeutic options but also presents significant challenges for infection control. Continued monitoring of global epidemiology and emerging drug resistance data is critical for the effective management of these infections.

Emergence of methicillin-resistant Staphylococcus aureus in the Maternity Hospital, Kuwait.

OBJECTIVE: To establish the relatedness of methicillin-resistant Staphylococcus aureus (MRSA) isolates in the Maternity Hospital, Kuwait. MATERIALS AND METHODS: A total of 22 MRSA were isolated from 20 neonates and 1 mother in the Special Care Unit, Maternity Hospital, Kuwait. They were characterized using antibiogram, pulsed-field gel electrophoresis (PFGE), SCCmec typing, spa typing and multi locus sequence typing (MLST), and were screened for genes encoding Panton Valentine leukocidin (PVL) and capsular polysaccharide types 5 and 8. RESULTS: The isolates were resistant to cadmium acetate (n = 22 or 100%), trimethoprim (n = 13 or 59.1%), gentamicin (n = 7 or 31.8%), ciprofloxacin (n = 5 or 22.7%), erythromycin and clindamycin (n = 2 or 9.1%), tetracycline (n = 2 or 9.1%) and fusidic acid (n = 2 or 9.1%). Eight isolates contained genes for PVL while 15 and 6 carried genes for types 5 and 8 capsular polysaccharide, respectively. Molecular typing distinguished 12 clones. Ten of these clones consisted of 20 isolates belonging to ST60-SCCmec-IV-t3935 (5 isolates), ST6-SCCmec-IV-t6269 (4 isolates), ST194-SCCmec-IV-t6892 (3 isolates), ST1-SCCmec-V-t2962 (2 isolates) and 1 isolate each of ST77-SCCmec-IV-t339, ST935-SCCmec-V-t1084, ST1317-SCCmec-V-t1548, ST9-SCCmec-V-t5801, ST627-SCCmec-IV-t1340 and ST2148-SCCmec-IV-t2810. CONCLUSION: The study demonstrated the emergence of MRSA including novel ST60 and ST194 clones at the Maternity Hospital in Kuwait.

Genotypes and virulence genes in group B streptococcus isolated in the maternity hospital, Kuwait.

OBJECTIVE: To characterize group B streptococcus (GBS) isolates obtained from patients at the Maternity Hospital in Kuwait for their genotypes and carriage of virulence genes. MATERIALS AND METHODS: A total of 154 GBS isolates were obtained from July 1 to October 31, 2007, from vaginal swabs (n = 95), urine (n = 46), blood (n = 4) and miscellaneous sources (n = 9). Genotypes were obtained by pulsed-field gel electrophoresis (PFGE), following digestion with SmaI or EagI restriction enzymes. PCR was used to screen for the carriage of virulence genes including: surface protein of group B streptococcus (spb1), secreted fibrinogen-binding protein (fbsB), C5a peptidase (scpB), laminin-binding protein (lmb), α- (bca) and ß-subunits of the C protein (bac), resistance to protease immunity protein (rib), and phage-associated gene (pag); regulatory protein (dltR), and toxins CAMP factor (cfb), hyaluronidase (hylB) and superoxide dismutase (sodA). RESULTS: PFGE defined 14 genotypes differentiating isolates with the same serotypes into different genetic backgrounds. All isolates contained genes for virulence factors. However, cfb (99.4%), scpB (88.3%), lmb (88.3%), bca (57.8%), sodA (55.8%) and dltR (53.9%) were the common virulence genes. In total, 144 (90.3%) of the isolates contained 3 or more virulence genes. However, while cfb, lmb and scpB occurred in all genotypes, others occurred in some but not in all genotypes. CONCLUSIONS: GBS isolates obtained at the Maternity Hospital, Kuwait, belonged to diverse genetic backgrounds with the majority carrying multiple virulence genes.

Frequency and clinical association of Panton-Valentine leukocidin-positive Staphylococcus aureus isolates: a study from Kuwait.

OBJECTIVE: This study was undertaken to determine the frequency of Panton-Valentine leukocidin (PVL)-producing Staphylococcus aureus among strains isolated in our laboratory and to study the association of PVL-positive strains with clinical disease. MATERIALS AND METHODS: A total of 291 S. aureus isolates obtained from different clinical specimens from June 1, 2009, to March 31, 2010, at the Farwania Hospital Laboratory were investigated for antimicrobial susceptibility, carriage of genes for PVL, and SCCmec elements. Antimicrobial susceptibility testing was performed by standard methods. The presence of mecA genes for PVL SCCmec typing was determined by PCR. RESULTS: Of the 291 S. aureus isolates, 89 (30.6%) were methicillin-resistant S. aureus (MRSA), whereas 202 (69.4%) were methicillin susceptible (MSSA). Genes for PVL were detected in 13 (14.6%) and 24 (12.0%) of the MRSA and MSSA isolates, respectively. The majority of the PVL-producing MRSA and MSSA were isolated from 12 (30.7%) and 19 (21.8%) cases of skin and soft tissue infections (SSTI), respectively. Although both MSSA and MRSA strains were uniformly susceptible to rifampicin, teicoplanin, and vancomycin, multidrug resistance was observed among PVL-producing and nonproducing MRSA isolates. Both MRSA types carried SCCmec type III, IV, IVc, and V genetic elements. CONCLUSION: This study revealed the presence of genes for PVL in both MSSA and MRSA, associated mostly with SSTI and respiratory tract infections, supporting previous observations that PVL production is widespread among S. aureus strains obtained from different clinical sources.

Methicillin-Resistant Staphylococcus aureus (MRSA) in a Tertiary Care Hospital in Kuwait: A Molecular and Genetic Analysis.

Methicillin-resistant Staphylococcus aureus (MRSA) is a major pathogen that causes serious infections in healthcare facilities and in communities. The purpose of this study was to investigate MRSA isolates obtained in a tertiary hospital in Kuwait to assess their antibiotic susceptibility profile and clonal composition. Sixty MRSA isolates collected in 2020 were tested through antibiotic susceptibility testing, spa typing, and DNA microarray analysis. All isolates were found to be susceptible to vancomycin (MIC: ≤3 µg/mL), teicoplanin (MIC: ≤3 µg/mL), rifampicin, and mupirocin, but were resistant to fusidic acid (n = 43, 72%), trimethoprim (n = 27, 45%), ciprofloxacin (n = 31, 51.7%), gentamicin (n = 14; 23.3%), kanamycin (n = 20; 33.3%), chloramphenicol (n = 7; 11.7%), tetracycline (n = 17; 28.3%), erythromycin (n = 19; 31.6%), inducible clindamycin (n = 13; 21.7%), and constitutive clindamycin (n = 2; 3.3%). The isolates belonged to 30 spa types and 13 clonal complexes (CCs). The dominant spa types were t304, t442, t311, t688, and t1234, collectively constituting 28.3% of the isolates. The dominant CCs were CC5 and CC6, which together constituted 46.7% of the isolates. This study provides updated research on antibiotic resistance and changes in the clonal composition of MRSA in a Kuwait hospital, including the disappearance of the ST239-MRSA-III clone that was previously the dominant clone in this hospital.

Effects of varied substituents on the antibacterial activity of triazolylmethyl oxazolidinones.

A number of 1,2,3-triazolylmethyl piperazino oxazolidinone derivatives with optionally varied substituents at the 4N-piperazine position were synthesized and their antibacterial activity evaluated against a panel of susceptible and resistant Gram-positive and selected Gram-negative bacteria. Substitution with 5-membered heteroaroyl and dinitrobenzoyl moieties potentiated activity against staphylococci and enterococci strains. Furthermore, the compounds having dinitrobenzoyl 7n, 7o, and 5-nitrofuroyl 7t substitutions were four- to eightfold more potent than linezolid against M. catarrhalis. However, substitution of guanidino and other water-solubilizing functionalities at the 4N-piperazine position resulted in compounds that are devoid of antibacterial activity.

Diversity of clonal complex 22 methicillin-resistant Staphylococcus aureus isolates in Kuwait hospitals.

CC22-MRSA is a major MRSA lineage that is widely reported globally. To characterize CC22-MRSA for trends in antibiotic resistance and emergence of variants, a total of 636 CC22 isolates identified by DNA microarray in 2016 (n = 195), 2017 (n = 227) and 2018 (n = 214) were investigated further using staphylococcal protein A (spa) typing and multilocus sequence typing. The isolates belonged to 109 spa types dominated by t223 (n = 160), t032 (n = 60), t852 (n = 59), t005 (n = 56) and t309 (n = 30) and 10 sequence types (STs) dominated by ST22 (85.5%). Genotypes CC22-MRSA-IV [tst1+]; CC22-MRSA-IV UK-EMRSA-15/Barnim EMRSA variants, CC22-MRSA-IV [PVL+], CC22-MRSA-IV [tst1+/PVL+] and CC22-MRSA-IV + V constituted >50% of the isolates. An increase from 2016 to 2018 were shown in isolates belonging to spa types t223 (43 to 62), t032 (18 to 27) and t309 (10 to 15) and genotypes CC22-MRSA-IV [tst1+] (89 to 102), CC22-MRSA-IV + V (12 to 30) and CC22-MRSA-IV [tst1+/PVL+] (12 to 22). Ninety-nine CC22-MRSA isolates were multi-resistant to three or more antibiotic classes with 76.7% of them belonging to CC22-MRSA-IV [PVL+] and CC22-MRSA-IV [tst1+/PVL+]. The study revealed an ongoing domination of the CC22-MRSA-[tst1+] genotype and the emergence of new clones bearing SCCmec IV + V and multiply resistant variants.

Frequency of virulence-associated genes in Enterococccus faecalis isolated in Kuwait hospitals.

OBJECTIVE: The objective of this study was to investigate the carriage of 6 virulence-associated genes in Enterococcus faecalis isolates obtained from patients in 8 hospitals in Kuwait. MATERIALS AND METHODS: In total, 466 E. faecalis isolates were obtained from 313 urine samples, 68 wound swabs, 36 blood samples, 25 rectal swabs, 12 high vaginal swabs and 12 miscellaneous sources. Genes for gelatinase(gelE),aggregation substance (aggA), hemolysin activation factor (cylA), enhanced expression of pheromone (eep), enterococcal surface protein (esp), and E. faecalis endocarditis antigen A (efaA) were detected in PCR assays. RESULTS: Of 466 isolates, 423 (90.8%) were positive for 1 and up to 5 genes. However, none of the genes was detected in all of the isolates. The prevalence of the individual genes was eep: 31.9%; esp: 31.5%; gelE: 28.5%; efaA: 27.9%; aggA: 23.4%, and cylA: 18.5%. Of the 423 positive isolates, 148 (34.9%) were positive for 2 genes and 52 (12.3%), 15 (3.5%) and 5 (0.9%) isolates were positive for 3, 4 and 5 virulence genes, respectively. The efaA and esp combination was detected in isolates from all clinical sources. CONCLUSION: The study showed a high prevalence of virulence genes in E. faecalis isolated in Kuwait hospitals. The absence of a dominant gene in all of the isolates suggests that infections by E. faecalis may require the involvement of multiple virulence factors.

Trafficking of methicillin-resistant staphylococci and co-colonization with vancomycin-resistant enterococci.

OBJECTIVES: To determine the trafficking of methicillin-resistant staphylococci between the hospital and community as well as the occurrence of co-colonization with vancomycin-resistant enterococci (VRE). SUBJECTS AND METHODS: From November 2005 to April 2006, methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant coagulase-negative Staphylococcus (MRCoNS)-positive patients at the Salmaniya Medical Complex, Bahrain were assessed for VRE co-colonization. Characterization of vancomycin resistance genotype by PCR was carried out. Close family contacts were screened for MRSA and pulsed-field gel electrophoresis (PFGE) analysis of MRSA isolates from patient-family member pairs was conducted. RESULTS: One hundred and eighty-two patients (93 MRSA; 89 MRCoNS) and 356 family members were enrolled. Seven MRSA and 41 MRCoNS strains were isolated from the family members. PFGE analysis revealed the presence of variants of a single MRSA clone among patients and their relatives. A total of 112 patients (62 MRSA; 50 MRCoNS) provided stool for VRE screening. Of these 13 stool specimens (11.6%) were VRE-positive. All the VRE isolates were from MRSA-positive patients, thus positivity rate among MRSA patients was 20.9% (n/N = 13/62). These were predominantly Enterococcus gallinarum with vanC1 genotype and one strain was Enterococcus faecium (vanB genotype). Two E. gallinarum isolates harbored an additional vanB gene. The majority of VRE isolates were from patients in medical and surgical units (n/N = 10/13; 77%). Male gender, prolonged hospitalization and presence of co-morbidities were significantly associated with MRSA/VRE co-colonization (p < 0.05). CONCLUSION: MRSA/VRE co-colonization with MRSA trafficking between the hospital and community environment is a public health concern occurring in our setting.

DNA microarray analysis of Staphylococcus aureus from Nigeria and South Africa.

Staphylococcus aureus is an important human pathogen with an arsenal of virulence factors and a propensity to acquire antibiotic resistance genes. The understanding of the global epidemiology of S. aureus through the use of various typing methods is important in the detection and tracking of novel and epidemic clones in countries and regions. However, detailed information on antibiotic resistance and virulence genes of S. aureus, and its population structure is still limited in Africa. In this study, S. aureus isolates collected in South Africa (n = 38) and Nigeria (n = 2) from 2001-2004 were characterized by spa typing and DNA microarray. The combination of these two methods classified the isolates into seven spa types and three clonal complexes (CCs) i.e. t064-CC8 (n = 17), t037-CC8 (n = 8), t1257-CC8 (n = 6), t045-CC5 (n = 5), t951-CC8 (n = 1), t2723-CC88 (n = 1), t6238-CC8 (n = 1), and untypeable-CC8 (n = 1). A high percentage agreement (>95%) and kappa coefficient (>0.60) was largely observed with antibiotic susceptibility testing and DNA microarray, indicating substantial agreement. Some antibiotic and virulence gene markers were associated with specific clones. The detection of the collagen-binding adhesion (cna) gene was unique for t037-CC8-MRSA while the enterotoxin gene cluster (egc) and staphylococcal complement inhibitor (scn) gene were identified with t045-CC5-MRSA. Moreover, the combination of genes encoding enterotoxins (entA, entB, entK, entQ) was noted with most of the CC8 isolates. The t045-CC5-MRSA clone was positive for the mercury resistance (mer) operon. DNA microarray provides information on antibiotic resistance and virulence gene determinants and can be a useful tool to identify gene markers for specific S. aureus clones in Africa.

Resurgence of Chloramphenicol Resistance in Methicillin-Resistant Staphylococcus aureus Due to the Acquisition of a Variant Florfenicol Exporter (fexAv)-Mediated Chloramphenicol Resistance in Kuwait Hospitals.

Following a surge in the prevalence of chloramphenicol-resistant methicillin-resistant Staphylococcus aureus (MRSA) in Kuwait hospitals, this study investigated the genotypes and antibiotic resistance of the chloramphenicol-resistant isolates to ascertain whether they represented new or a resurgence of sporadic endemic clones. Fifty-four chloramphenicol-resistant MRSA isolates obtained in 2014-2015 were investigated. Antibiotic resistance was tested by disk diffusion and MIC determination. Molecular typing was performed using spa typing, multilocus sequence typing, and DNA microarray. Curing and transfer experiments were used to determine the genetic location of resistance determinants. All 54 isolates were resistant to chloramphenicol (MIC: 32-56 mg/L) but susceptible to florfenicol. Two chloramphenicol-resistance determinants, florfenicol exporter (fexA) and chloramphenicol acetyl transferase (cat), were detected. The fexA-positive isolates belonged to CC5-ST627-VI-t688/t450/t954 (n = 45), CC5-ST5-V-t688 (n = 6), whereas the cat-positives isolates were CC8-ST239-III-t037/t860 (n = 3). While cat was carried on 3.5-4.4 kb plasmids, the location of fexA could not be established. DNA sequencing of fexA revealed 100% sequence similarity to a previously reported fexA variant that confers chloramphenicol but not florfenicol resistance. The resurgence of chloramphenicol resistance was due to the introduction and spread of closely related fexA-positive CC5-ST5-V and CC5-ST627-VI clones.