Staphylococcal Strains Research Articles

Draft Genome Sequence of the Thermophilic Bacterium Bacillus licheniformis SMIA-2, an Antimicrobial- and Thermostable Enzyme-Producing Isolate from Brazilian Soil.

Bacillus licheniformis SMIA-2, a thermophilic and thermostable enzyme-producing bacterium, is found to be active against several strains of Staphylococcus aureus and several Bacillus species. Here, we report the 4.30-Mbp draft genome and bioinformatic predictions supporting gene inventories for amylase, protease, cellulase, xylanase, and antimicrobial compound biosynthesis.

Molecular detection of methicillin heat-resistant Staphylococcus aureus strains in pasteurized camel milk in Saudi Arabia.

Antibiotic- and heat-resistant bacteria in camel milk is a potential public health problem. Staphylococcus aureus (S. aureus) is an opportunistic pathogen in humans, dairy cattle and camels. We characterized the phenotype and genotype of methicillin-resistant staphylococcal strains recovered from pasteurized and raw camel milk (as control) distributed in the retail markets of Saudi Arabia. Of the 100 samples assessed between March and May 2016, 20 S. aureus isolates were recovered from pasteurized milk, 10 of which were resistant to cefoxitin, and as such, were methicillin-resistant. However, raw camel milk did not contain methicillin-resistant S. aureus (MRSA). Antimicrobial susceptibility tests showed that the resistance ratio for other antibiotics was 60%. We performed a polymerase chain reaction (PCR) assay using primers for the methicillin-resistant gene mecA and nucleotide sequencing to detect and verify the methicillin-resistant strains. Basic local alignment search tool (BLAST) analysis of the gene sequences showed a 96–100% similarity between the resistant isolates and the S. aureus CS100 strain’s mecA gene. Ten of the methicillin-resistant isolates were heat-resistant and were stable at temperatures up to 85°C for 60 s, and three of these were resistant at 90°C for 60 or 90 s. The mean decimal reduction time (D85-value) was 111 s for the ten isolates. Sodium dodecyl sulfate (SDS)/polyacrylamide gel electrophoresis (PAGE) showed that there was no difference in the total protein profiles for the ten methicillin heat-resistant S. aureus (MHRSA) isolates and for S. aureus ATCC 29737. In conclusion, a relatively high percentage of the tested pasteurized camel milk samples contained S. aureus (20%) and MHRSA (10%).

Value of multiplex PCR for detection of antimicrobial resistance in samples retrieved from patients with orthopaedic infections

BackgroundThe performance of multiplex PCR (mPCR) for detection of antimicrobial resistance from clinical isolates is unknown. We assessed the ability of mPCR to analyse resistance genes directly from clinical samples.Patients with orthopedic infections were prospectively included. Phenotypical and genotypical resistance was evaluated in clinical samples (synovial and sonication fluid) where identical pathogens were identified by culture and mPCR.ResultA total of 94 samples were analysed, including 60 sonication fluid and 34 synovial fluid samples. For coagulase-negative staphylococcus strains, mPCR detected resistance to oxacillin in 10 of 23 isolates (44%) and to rifampin in none of 6 isolates. For S. aureus isolates, detection rate of oxacillin and rifampin-resistance was 100% (2/2 and 1/1, respectively). Fluoroquinolone-resistance was confirmed by mPCR in all 3 isolates of Enterobacteriaceae, in enterococci resistance to aminoglycoside-high level was detected in 1 of 3 isolates (33%) and in streptococci resistance to macrolides/lincosamides in none of 2 isolates. The overall sensitivity for different pathogens and antimicrobials was 46% and specificity 95%, the median concordance was 80% (range, 57–100%). Full agreement was observed for oxacillin in S. aureus, vancomycin in enterococci, carbapenems/cephalosporins in Enterobacteriaceae and rifampin in Cutibacterium species.ConclusionThe overall sensitivity for detection of antimicrobial resistance by mPCR directly from clinical samples was low. False-negative mPCR results occurred mainly in coagulase-negative staphylococci, especially for oxacillin and rifampin. However, the specificity of mPCR was high and a positive result reliably predicted antimicrobial resistance. Including universal primers in the PCR test assay may improve the detection rate but requires additional sequencing step.Trial registrationwww.clinicaltrials.gov No. NCT02530229, registered at 21 August 2015 (retrospectively registered).

Effect of Perioperative Antibacterial Prophylaxis Using Eye Drops with Fluoroquinolones on Conjunctival Microflora in Patients before and after Phacoemulsification

Purpose. to evaluate the efficacy of perioperative antibacterial prophylaxis using eye drops with fluoroquinolones with the evaluation of conjunctival microflora structure with its antibiotic resistance.Patients and Methods. The study was carried out using the results of one preoperative and four times postoperative swabs taken from the conjunctival cavity in 50 patients (52 eyes) aged 49 to 91 undergoing phacoemulsification. All the strains were undergoing the 16 antibacterial drugs-panel susceptibility testing including the most common ophthalmic dosage form in the Russian Federation. The antibacterial drugs instillations were used during the postoperative period: levofloxacin in group 1 (30 eyes) and moxifloxacin in group 2 (22 eyes).Results. The structure of conjunctival microflora in the two groups was similar prior to phacoemulsification. In 32 cases (61.5 %) bacterial growth was obtained preoperatively. Among them S. epidermidis strains were detected in 68.8 %, S. aureus strains were detected in 31.2 %. During the use of postoperative antibiotic prophylaxis, the number of positive swabs was constantly decreasing. In 1 hour a qualitative change in the microflora structure was observed. The number of S. aureus strains reduced. The number of S. epidermidis strains increased to 80 %. And previously undetected Corynebacterium spp. strains were found. In 1 day the conjunctival microflora was represented only by S. epidermidis. In 1 week all the swabs were sterile. In 1 month after phacoemulsification, positive swabs were obtained in 7.7 % (mainly S. epidermidis) only in group 1, where levofloxacin instillations were used as the postoperative antibiotic prophylaxis (р < 0,05). Moxifloxacin, gatifloxacin and antiseptic drugs showed the highest in vitro activity against selected strains.Conclusion. The strains of coagulase-negative staphylococcus S. epidermidis prevailed in conjunctival microflora structure. During the use of postoperative antibiotic prophylaxis, the number of positive swabs is progressively reduced to zero by the 7th day in both groups. A more persistent permanent effect of moxifloxacin, maintaining for 1 month after the operation was found in comparing two patients’ groups received fluoroquinolone eye drops to prevent infection after phacoemulsification.

Clinical Features of Infection within 100 days after Hematopoietic Stem Cell Transplantation in 313 patients with Hematologic Diseases

To analyze the clinical characteristics of infection within 100 days after hematopoietic stem cell transplantation (HSCT) in patients with hematologic disease. The culture results of 313 HSCT patients infected in the hematology department of our hospital from January 2013 to January 2019 were collected, and the infection incidence, pathogen distribution, drug susceptibility test results and infection risk factors out of them all were analyzed. Among 313 HSCT patients, infection occurred within 100 days in 262(83.7%) patients, 234 (89.3%) cases were in neutropenic period at infection onset. 156 pathogen distributions showed that the bloodstream infection (64.1%) ranked first. Among isolates, Gram-negative bacteria was 86 (55.1%), which were higher than Gram-positive bacteria (49, 31.4%), and fungi was 21(13.5%). The prevalence of ESBLs in E.coli and Klebsiella pneumoniae were 36.4% and 31.6%, respectively. The drug resistance rates of E.coli and Klebsiella pneumoniae to carbapenems were 18.20% and 5.3%, respectively, and to amikacin were 29.5% and 10.5%, respectively. The antimicrobial resistance of fermentation bacteria was significantly different. The drug resistence rates of Pseudomonas aeruginosa and Acinetobacter baumannii to carbapenems were high. Only one strain of methicillin-resistant staphylococcus aureus (MRSA) was found. The drug resistence rates of enterococcus faecalis to linezolid was 14.30%. The sensitivity of other Gram-positive bacteria to vancomycin, teicolanin and linezolid was 100%. The HSCT in our hospital was mainly allogeneic, and univariate analysis showed that the risk factors for infection were status before trasplantion, HLA matching type,length of stay for the first transplant, and length of neutropenia, while Mulvariate analysis showed that only HLA matching type showed statistical significance. The infection of patients after HSCT occurrs in period of neutropenia, Most of pathogens are G- bacteria, and the resistance to antibiotics is quite common, HLA mismatch is allo-HSCT independent risk factors for infection. It is very imprtant to monitor actively the distribution of pathogenic bacteria, drug-resistance and risk factors of infection for guiding more reasonable and standardized clinical treatment.

Direct Detection of Methicillin Resistant Staphylococci: Comparison of Phenotypic Methods with Multiplex PCR and Direct Susceptibility Testing

Bloodstream infections are augean diseases characterized by a high morbidity and mortality, related with the lag in administration of the first adequate anti-infectious agent. Clinical and epidemiological data guide the clinicians towards empirical anti-infectious treatments whose effectualness remains questionable especially in the present day milieu of multidrug-resistant organisms. Early microbiological evidence of the causative agent is hierophantic of antimicrobial stewardship. We evaluated three rapid methods for the direct identification of S. aureus from 720 positive blood cultures in comparison to Vitek 2 automated microbial identification system. Early distinction S. aureus from CoNS was attempted with Direct Tube Coagulase. Multiplex PCR assay was used to separate MRSA from MSSA by the presence of mecA gene. Direct antibiotic susceptibility (DST) from positive blood culture bottles was performed in an endeavour to reduce time and compared to the routine Vitek 2 compact antimicrobial susceptibility. For Direct tube coagulase at 4 hrs of incubation sensitivity was 79.6% while specificity was 100% however, on overnight incubation sensitivity increased to 97.9% with 100% specificity. The positive predictive value and negative predictive values were 100% and 96.9% respectively when compared to Vitek 2 identification of staphylococcal species. By DST Categorical agreement of 95% was seen for coagulase negative staphylococci microorganism-antibiotic combinations. Categorical agreement of 89.7% was seen for S. aureus microorganism-antibiotic combinations. Direct multiplex PCR testing did not misidentify any S. aureus isolate compared to Vitek 2. In 12 methicillin resistant CoNS isolates mecA gene was not detected by PCR. In total 13(3.5%) strains of staphylococci identified by DST as methicillin resistant were not identified by PCR analysis. Each of the tests has positive qualities and all may have a place in a Gram positive cocci algorithm for testing blood cultures depending on the laboratory setting, workload volume and staffing. However, rapid detection methods are a pressing priority.

In Vitro Efficiency of Antimicrobial Peptides against Staphylococcal Pathogens Associated with Canine Pyoderma.

Simple SummaryCoagulase-positive staphylococci (CoPS) are predominant pathogens in canine pyoderma, especially S. pseudintermedius and S. aureus. The antimicrobial resistance of CoPS has a key role in the management of canine skin infections. The vast majority of those diseases have a chronic character with a tendency to recur, which is reflected by recurrent systemic antibiotic therapy, associated with an alarming increase in the proportion of antibiotic-resistant staphylococci. Antimicrobial peptides (AMPs) seem to be a promising alternative to conventional antibiotics. The aim of this in vitro study was to evaluate the antimicrobial activity of selected AMPs against pathogenic staphylococcal strains, including multidrug- and methicillin-resistant strains isolated from canine pyoderma cases. The tested AMPs were shown to be equally efficient antimicrobial agents against resistant- and susceptible pathogenic staphylococcal strains associated with canine pyoderma. AMPs were more efficient against S. pseudintermedius than against S. aureus strains. Our findings seem to be particularly interesting from a clinical perspective, as a starting point from which to perform in vivo experiments to estimate the usefulness of these peptides as topical drug molecules for the treatment of canine pyoderma.The emergence of staphylococcal canine pathogens resistant to multiple antimicrobial agents is a growing and urgent problem in veterinary practice. Antimicrobial peptides (AMPs) seem to be a promising alternative to conventional antibiotics. The aim of this in vitro study was to evaluate the antimicrobial activity of selected AMPs against pathogenic staphylococcal strains, including multidrug- and methicillin-resistant strains isolated from canine pyoderma cases. Seven antimicrobial peptides (aurein 1.2, CAMEL, citropin 1.1, protegrin-1, pexiganan, temporin A and uperin 3.6) synthesized by the 9-fluorenylmethoxycarbonyl (Fmoc) solid-phase method were tested. The minimal inhibitory and minimal bactericidal concentrations (MIC and MBC) were determined by the broth microdilution method. The study showed that analyzed AMPs exerted an extensive effect against canine pathogens, with the most active peptide being uperin 3.6. The tested AMPs were equally efficient against both resistant- and susceptible staphylococcal strains and were more efficient against Staphylococcus pseudintermedius than against Staphylococcus aureus strains. Our findings are particularly interesting from a clinical perspective, as they point to AMPs as potential therapeutic topical agents in canine pyoderma cases associated with antimicrobial resistance of staphylococci.

Infection Risks and Antimicrobial Resistance in Tertiary Hospitals in Benin: Study Cases of Sakété-Ifangni and Menontin Hospitals

Background: Antimicrobial resistance surveillance and infection risk assessment are important for optimizing the quality of healthcare in hospitals. Objectives: This study aimed to evaluate the antimicrobial resistance and infection risks in Tertiary hospitals in Benin. Methods: Bacteriological examinations were carried out on swab samples from the hospital environment at Sakete-Ifangni Hospital and Menontin Hospital in Benin. The environmental swabs were supplemented with wound swabs from Menontin Hospital. In both hospitals, antibiotic susceptibility of the isolated strains was determined by the agar diffusion method. Results: The results showed that coagulase-negative staphylococci (45%) comprised the most isolated species in the environment of the Surgery and Operating Departments of Sakete-Ifangni Hospital, followed by Staphylococcus aureus (27.50%) and Proteus spp. (15%). At Menontin Hospital, only one specimen was sterile from wound swabs. From environmental swabs, 29 out of 45 samples were positive. Staphylococcus aureus (31%), Escherichia coli (15%), and coagulase-negative staphylococci (12%) were the most isolated species from wounds. Strains of coagulase-negative staphylococci (29%), Pseudomonas aeruginosa (15%), and Proteus mirabilis (12%) were the most common strains in swabs. The study of the adequacy of treatment of infections caused by bacteria responsible for wound suppuration showed that 52% of the wounded received appropriate antibiotic treatment. At Menontin Hospital, many isolated strains from room environment samples were found in the wounds of the patients. In both hospitals, the isolated strains were multiresistant to conventional antibiotics. Conclusions: These data show how surveillance of infection risks and antimicrobial resistance is important to prevent healthcare-associated infections.

Antibacterial activity of singly and doubly modified salinomycin derivatives

The increasing challenge of antibiotic resistance stimulates the search for novel antibacterial agents, especially such that would be effective against multi-drug resistant bacterial strains. Fortunately, natural compounds are excellent sources of potentially new drug leads. Particularly interesting in this context are polyether antibiotic salinomycin (SAL) and its semi-synthetic derivatives, as they exhibit large spectrum of bioactivity. We synthesized and evaluated the antibacterial activity of a series of SAL analogs; four singly (2–3, 15, 17) and two doubly modified (16, 18) derivatives were found to show excellent inhibitory activity not only against planktonic Gram(+) bacterial cells, but also towards select strains of methicillin-resistant staphylococci with the MIC values of 1–4 µg mL−1. Of note, the most promising candidates were more effective in preventing bacterial biofilm formation than unmodified SAL and a commonly used antibiotic – ciprofloxacin. Furthermore, we proved that rational modification of C20 hydroxyl of SAL may reduce genotoxic properties of the obtained analogs. Mechanistically, the structure-activity relationship studies suggested that electroneutral transport mechanism could be beneficial in terms of ensuring high antibacterial activity of SAL derivatives.

Draft Genome Sequence of a New Staphylococcal Species Isolated from Human Skin

A hemolytic staphylococcal strain, Staphylococcus sp. strain 170179, was isolated from healthy human skin. Genome sequencing and comparison of strain 170179 to other staphylococci revealed a relatedness to Staphylococcus haemolyticus with an average nucleotide identity of 87.5%, indicating that Staphylococcus sp. 170179 belongs to a separate species.

A history of the discovery of bacteriophages. Will the well - forgotten old become new?

Staphylococcus is considered to be one of the most common pathogens that can lead to the development of numerous pathological processes, from pyoderma to peritonitis. Being a potentially pathogenic microorganism, it is able not to make itself noticed for years, peacefully coexisting with the host organism. But should one only go through a viral infection out of bed, suffer from stressful situations, or simply get overcooled, the potentially pathogenic microflora activates and manifests itself as a local or general infectious process. Activation of staphylococcal microflora is most often observed in sickly people with weakened immune systems, suffering from endocrine diseases, having long ellneses. Long-term and uncontrolled use of antibiotics with the formation of resistance to them is also of great importance. It is the widespread distribution of antibiotic-resistant strains of staphylococcus that makes doctors and scientists look for new forms of controling this and other microorganisms. Against this background, it’s time to recall the bacteriophages long forgotten in the era of the craze for antibiotics, especially given the fact that over the past thirty years not a single completely new group of antibacterial agents has been synthesized.

Exploring the Ambiguous Status of Coagulase-Negative Staphylococci in the Biosafety of Fermented Meats: The Case of Antibacterial Activity Versus Biogenic Amine Formation.

A total of 332 staphylococcal strains, mainly isolated from meat, were screened for antibacterial activity. Eighteen strains exhibited antibacterial activity towards species within the same genus. These antibacterial strains were further screened against Clostridium botulinum, to assess their potential as anticlostridial starter cultures for the development of fermented meat products without added nitrate or nitrite. Only Staphylococcus sciuri IMDO-S72 had the ability to inhibit all clostridial strains tested, whilst displaying additional activity against Bacillus cereus, Listeria monocytogenes and Staphylococcus aureus. Apart from their potential as bioprotective cultures, the staphylococcal collection was also screened for biogenic amine production, as these compounds may compromise food quality. To this end, ultra-high-performance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS) was applied. A low incidence of biogenic amine production was found, with tyramine and β-phenylethylamine being the most prevalent ones. Concentrations remained relatively low (< 52 mg/L) after a prolonged incubation period, posing no or little threat towards food safety. Taken together, S. sciuri IMDO-S72 could serve as an interesting candidate for the bioprotection of fermented meats as it showed promising antibacterial activity as well as absence of biogenic amine production.

Rapid Staphylococcus aureus Detection From Clinical Mastitis Milk by Colloidal Gold Nanoparticle-Based Immunochromatographic Strips.

Rapid diagnostic technologies for bovine mastitis caused by Staphylococcus aureus (S. aureus) are urgently needed. In the current study, we generated an anti-ribosomal protein-L7/L12 antibody to detect S. aureus and an anti-ribosomal protein-L7/L12 antibody-coated immune-chromatographic strip (ICS) test. Moreover, we determined the ability of the ICS test to detect S. aureus from milk samples collected from cows with clinical mastitis. The developed ICS reacted to S. aureus in a bacteria load-dependent manner with a detection limit of ~104 CFU/mL. In the evaluation of possible cross-reactivity of the ICS test, six strains of coagulase-negative Staphylococci showed slightly positive reactions, although at a lower level; however, other bacteria were completely negative. Next, we investigated the sensitivity and specificity of the ICS test compared with the bacteriological culture method using milk samples from clinical bovine mastitis. The results of the experiments demonstrated that the ICS test had high sensitivity [100%, 95% confidence interval (CI): 91.3–100%] and specificity (91.9%, CI: 90.5–91.9%) compared with culture tests. In addition, the kappa statistic demonstrated that ICS tests showed substantial agreement (k = 0.77, CI: 0.66–0.87) with culture tests. Positive correlations were observed for the statistical analysis between S. aureus (nuc gene) copy numbers and ICS test scores in mastitic milk infected by S. aureus. Therefore, we assume that this new detection method using ICS may be useful as a highly sensitive S. aureus-screening method for the diagnosis of bovine mastitis. Our findings support the ongoing effort to develop an ICS method for bovine S. aureus-induced mastitis, which can contribute to the rapid diagnosis of this disease.

Prevalence and antimicrobial resistance of Staphylococcus species isolated from cats and dogs.

Background:Methicillin-resistant staphylococci (MRS) are an emerging global problem with serious public health concern.Aims:This study investigated the prevalence and antimicrobial susceptibility of commensal Staphylococcus species isolated from healthy and clinical cats and dogs.Methods:Nasal swab samples were collected from animals and processed using selective and semi-selective mediums. Presumptive isolates were subjected to biochemical testing and analyzed using the Phoenix automated identification and susceptibility testing system. PCRs protocols were used to screen for mecA and pvl genes.Results:In total, 151 pets (103 cats and 48 dogs) were enrolled, of which 14 dogs (29%) and 24 cats (23%) were colonized with various Staphylococcus species mainly originated from healthy animals. A total of 38 staphylococci isolates were collected and distributed between 24 coagulase-negative and 14 coagulase-positive staphylococci. Only 13 staphylococci strains were identified as MRS, out of which only five isolates expressed that the mecA gene exclusively originated from healthy pets.Conclusion: This is the first study reporting the prevalence and colonization status of staphylococci species and MRS strains isolated from cats and dogs in Libya. The study reports important information of medical and clinical importance on antimicrobial and multidrug resistance of different staphylococci strains, particularly the coagulase negative species.

Antimicrobial resistance of staphylococci in pediatric hospitals

Objective. To determine frequency of Staphylococcus isolation and antimicrobial resistance in hospitalized children with different types of infections. Materials and Methods. Species identification and antimicrobial susceptibility testing in staphylococci were performed on a WalkAway 96 analyzer using Pos Combo type 20 tablets, and mecA gene detection was performed on a RotorGene 6000 amplifier with a set of AmpliSens MRSA-screen FL. Results. A total of 876 strains of staphylococci isolated in children’s hospitals were tested. The species and antibiotic resistance of Staphylococcus aureus and coagulase-negative staphylococci were studied. The most common types of staphylococci were: S. aureus – 36.0%, S. epidermidis – 23.0%, S. haemolyticus – 19.7%, S. hominis – 14.0%. As many as 35.3% of isolates were methicillin-resistant, while 32.9% of methicillin-resistant S. aureus was detected, and 65.6% of methicillin-resistant strains were among the most frequently isolated coagulase-negative staphylococci. The mecA gene was detected in 97.1% of phenotypically methicillin-resistant strains. Antibiotic resistance of S. aureus and coagulase-negative staphylococci circulating in children’s hospitals is very high. Two strains of S. aureus with intermediate resistance to vancomycin (MIC = 4 mcg/ml) and one S. aureus with resistance to linezolid (MIC = 8 mcg/ ml) were isolated. Among coagulase-negative staphylococci, two strains with intermediate resistance to vancomycin (MIC = 8 mcg/ml), two resistant to vancomycin (MIC = 16 mcg/ml), and 6 strains resistant to linezolid (MIC from 8 to 32 mcg/ml) were identified. Conclusions. Antimicrobial resistance of staphylococci in children’s hospitals does not depend on the species, more than half of the isolated isolates are methicillin-resistant. During the reporting period, staphylococci resistant to vancomycin and linezolid were identified, which requires resistance mechanisms to be determined.

Визначення генетичної варіативності клінічних штамів S. aureus, вилучених із locus morbi та з інших біотопів у хворих на атопічний дерматит

The objective: the study of genetic affinity of S. aureus strains isolated from patients with AD Materials and methods. Genetic variability of the 79 S. aureus isolates was evaluated according to the results of the RAPD-PCR study. Results. It was revealed a generally high genetic polymorphism of S. aureus. It was established that with an increase in the severity of АD, the monotypism of pathogen isolates grows (p ≤ 0,05) from three different genetic clusters in patients with AD with a mild disease course to only one cluster with a severe disease course. A high level of genetic affinity was established between S. aureus strains isolated from different biotopes from the same patients, which for strains isolated from the nasal mucosa and from locus morbi reached (79,5 ± 1,6)%, and for strains isolated from intact and affected skin are as increased from (75,1 ± 4,4)% to (98,8 ± 0,8)% in parallel with the increase in the severity of the disease course in patients with AD from mild to severe forms, respectively (p ≤ 0,05). Conclusions. Both the generally high genetic polymorphism of S. aureus strains isolated from allergodermatosеs patients and the high affinity of isolates from different biotopes of the same patient, justify the auto-origin of the strains of staphylococci colonizing locus morbi.

Inducible Clindamycin and Methicillin Resistant Staphylococcus aureus Among Cancer Patients at University of Gondar Compressive Specialized Hospital, Northwest Ethiopia: Carriage Rate and Antibiotic Resistance Patterns.

Methicillin-resistant Staphylococcus aureus (MRSA) is a type of Staphylococcus aureus strain which is resistant to a group of beta-lactam antibiotics. Methicillin-resistance is due to a penicillin-binding protein, which has a low affinity for beta-lactam antibiotics. Excess and inappropriate use of clindamycin have led to the emergence of resistant Staphylococcal strains. Cancer patients are at high risk of bacterial colonization due to cancer chemotherapy which leads to severe and prolonged immunosuppression. This study aimed to assess the carriage rate of inducible clindamycin and MRSA among cancer patients. A hospital-based cross-sectional study was conducted on 200 cancer patients from January to August 2019. Sociodemographic data and nasal swab samples were collected and inoculated on mannitol salt agar and then incubated at 37°C for 24 hours. The identification of isolates was done by colony characteristics and biochemical reactions. MRSA was detected using cefoxitin disc and inducible clindamycin resistance detected using D-test. Interpretations of antibiotics susceptibility was done using CLSI 2018. Finally, data was entered, cleared, and checked using Epi-info version 7 and exported to SPSS version 20 for analysis. Logistic regression was used for statistical association. p-value ≤ 0.05 at 95% CI was considered statistically significant. In this study, of the 59 Staphylococcus aureus isolates tested, 22% (13/59) were MRSA and 78% (46/59) were MSSA. MRSA carriage rate in females was 18.6% (11/59) whereas in males it was 3.4% (2/59). MRSA carriage among urban residents (15.3% (9/59)) was higher than their rural counterparts (6.8% (4/59)). The prevalence of inducible clindamycin resistance was 17% (10/59). Multi-drug resistance patterns among Staphylococcus aureus isolates was 55.9% (33/59). Clindamycin (84.6%), chloramphenicol (84.6%), and ciprofloxacin (69.2%) were the most effective whereas penicillin (100%), tetracycline (76.9%), and erythromycin (76.9%) were the least effective for MRSA isolates. Urban living, being illiterate, being employed, patients with liver and lung cancer were significantly associated with MRSA carriage. This study showed high rates of MRSA carriage and inducible clindamycin resistance with the percentages of 22 and 17, respectively. Therefore, decolonization of MRSA carriers and rational usage of antibiotics should be implemented.

СТРУКТУРА МИКРОБНЫХ СООБЩЕСТВ НАЗЕМНЫХ СОЛЯНЫХ СООРУЖЕНИЙ ПЕРМСКОГО КРАЯ

The diversity of microbial communities the artificial salt constructions (ASC) located in the medicalpreventive and sanatorium institutions of the Perm region was studied. It was found that the surfaces of the abiotic salt of all ASC were contaminated with microorganisms, and a significant difference was found between the constructions of sylvinite (86.5% of positive samples) and halite (47.4%). The number of viable bacteria, as well as staphylococci, were also higher in sylvinite constructions than in halite ones. Based on bacteriological research and analysis of the 16S rRNA gene nucleotide sequences, the isolated staphylococcus strains belong to the following species: Staphylococcus epidermidis – 42.3% (n=11), S. aureus and S. saprophyticus – 19.2% (n=5), S. simulans – 7.7% (n=2) and one strain of S. cohnii urealyticum, S. hominis, S. warneri – 3.8%. The species composition of microbiocenoses formed on surfaces determined by gas chromatography–mass spectrometry included representatives of 18 genera belonging to the three main phylums: Actinobacteria, Firmicutes and Proteobacteria. Actinobacteria (Actinomyces, Corynebacterium, Nocardia, Propionibacterium, Rhodococcus, etc.) were dominant in both groups ASC. Among Firmicutes, representatives of the genus Clostridium predominated in sylvinite ASC – 63.8% of the total number of bacteria, while in halite they were half as many – 32.1%. The content of coccal microbiota, in contrast, in halite constructions was almost 3 times higher than in sylvinite. Identified quantitative and qualitative indicators of the microbiota of the ASC complement the understanding of the constructions of microbial communities under conditions of high salt load and anthropogenic impact.

Emergence of Multidrug-Resistant Staphylococci on Hand-Touching Surfaces in a University Town in Southwestern China: A Prevalence Study of Virulence and Resistance

Background: Staphylococcus aureus and coagulase-negative staphylococci are highly antibiotic-resistant pathogens and exhibit multiple virulence factors that threaten public health. However, few reports have evaluated the resistance and virulence of staphylococci in community settings. Objectives: This study surveyed the epidemiology, antimicrobial resistance, and virulence genes of staphylococci in the densely-populated university town of Kunming in Southwestern China. Methods: Various strains were isolated from hand-touching surfaces in Chenggong University Town, China, and identified via 16S rRNA sequencing. Staphylococci were isolated, and drug resistance was determined via antibiotic sensitivity testing. The mecA gene was verified and typed. Twelve virulence-associated genes and several disinfectant-resistance genes were determined. Results: One hundred sixty-three strains were collected from hand-touching surfaces, and more than a quarter of the isolates (46/163, 28.22%) were identified as staphylococci. Among the staphylococcal strains, 19 (41.30%) showed multidrug resistance, with resistance rates of more than 40% to benzyl-penicillin, erythromycin, oxacillin, and tetracycline. Twenty isolates (43.48%) carried mecA, and most staphylococcal cassette chromosome mecs (SCCmecs) were nontypeable. Twenty-eight strains (60.87%) carried at least one virulence gene; hemolysin genes were the most prevalent, and 22 strains (47.83%) carried qac genes. Staphylococcus aureus strain ST59 carried multiple resistance and virulence genes. Conclusions: Resistant staphylococci can easily adhere to hand-touching surfaces. More attention should be given to the appearance of resistance and virulence gene-harboring staphylococci in community settings. The findings herein suggest that effective disinfectant strategies and feasible surveillance measures are urgently needed.

Detection of enterotoxigenic strains &lt;i&gt;Staphylococcus aureus&lt;/i&gt;, producing SEC and SEI, isolated in patients with pneumonia, sepsis and burns

Aim. To identify the frequency of occurrence of staphylococcal enterotoxins of the SEC and SEI type produced by Staphylococcus aureus strains isolated from patients with different nosology. As you know, the infection process in them proceeds with severe intoxication without vomiting and intestinal disorders.Materials and methods. 79 strains were studied (43 were isolated in case of pneumonia, 13 - in burns, 11 - in sepsis) S. aureus in the presence of SES and SEI using enzymelinked immunosorbent assay (ELISA).Results. It was found that 48.3% of S. aureus strains isolated from patients with pneumonia produced SEC and 72.1% - SEI. The frequency of occurrence of S. aureus strains producing SEC and SEI isolated in patients with burn infections was 23.0 and 15.4%, respectively. 36.4% of staphylococcal strains isolated in patients with sepsis produced SEC, 45.5% - SEI.Discussion. It was found that the proportion of S. aureus cultures producing SEC enterotoxins during sepsis is significantly higher than the strains producing SEB (5.4%) and much smaller than SEA (75.6%). A high percentage of SEI-positive strains was found compared to strains that produce the classic enterotoxins SEA, SEB and SEC isolated from pneumonia. In burn infections, the proportions of strains producing SEC and SEI were 15.4 and 23.0%, respectively, which is significantly lower than SEA (92.9%).Conclusion. The data obtained indicate the need to identify staphylococcus strains that produce both classic and newly discovered enterotoxins, which are crucial virulence factors leading to lethal sepsis, infectious endocarditis and toxic shock syndrome to eliminate them.