Main Microorganisms Research Articles

Primary Spinal Infections in Patients With Hematologic Immunocompromising Conditions: A Systematic Literature Review

Primary spinal infections (PSIs) are a group of infectious diseases characterized by inflammation of the end plate-disk unit or its surroundings. PSI is considered more prevalent and aggressive among patients with chronic immunocompromised states. Association of PSIs, immunocompromising cancers, and hemoglobinopathies has not been systematically analyzed. We conducted a systematic review to study characteristics, clinical presentation, and mortality of patients with PSI in the setting of hematologic disease. A systematic literature search in PubMed, Web of Science, and Scopus was conducted in April 2022 in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We included retrospective case series and individual case reports. On careful review, 28 articles published between 1970 and 2022 were selected. These studies featured 29 patients who met inclusion criteria (mean age 29 years, age range 1.5 to 67 years; 63.3% male). Lumbar infection was the most common location (65.5%), with Salmonella (24.1%) as the main causative microorganism. Neurologic compromise was present in 41% of patients, and surgical intervention occurred in 48.3%. Average antibiotic duration was 13 weeks. The postoperative complication rate was 21.4%, with a mortality of 6.9%. PSI in patients with hematologic disease, while having shorter periods to diagnosis, presents increased rates of neurologic deficit, surgical intervention, and complications.

Taxonomical composition and functional analysis of biofilms sampled from a nuclear storage pool.

Sampling small amounts of biofilm from harsh environments such as the biofilm present on the walls of a radioactive material storage pool offers few analytical options if taxonomic characterization and estimation of the different biomass contributions are the objectives. Although 16S/18S rRNA amplification on extracted DNA and sequencing is the most widely applied method, its reliability in terms of quantitation has been questioned as yields can be species-dependent. Here, we propose a tandem-mass spectrometry proteotyping approach consisting of acquiring peptide data and interpreting then against a generalist database without any a priori. The peptide sequence information is transformed into useful taxonomical information that allows to obtain the different biomass contributions at different taxonomical ranks. This new methodology is applied for the first time to analyze the composition of biofilms from minute quantities of material collected from a pool used to store radioactive sources in a nuclear facility. For these biofilms, we report the identification of three genera, namely Sphingomonas, Caulobacter, and Acidovorax, and their functional characterization by metaproteomics which shows that these organisms are metabolic active. Differential expression of Gene Ontology GOslim terms between the two main microorganisms highlights their metabolic specialization.

A New Bacteriophage Of The Family Siphoviridae Isolated From The Soddy-Podzolic Soils Of The Prioksko-Terrasny Nature Reserve

Bacteria of the genus Streptomyces, one of the main microorganisms of soils, and their bacteriophages are important inhabitants of soil ecosystems. Important though they are, not much is known about their functional patterns and population dynamics. A question of particular interest, which is still to be understood, is how bacteriophages regulate the population dynamics of Streptomyces and how this regulation affects the soil ecosystem as a whole. Isolation and study of new Streptomyces bacteriophages can help to understand these problems. In this paper, we describe isolation of a new bacteriophage from the soils of the Prioksko- Terrasny Reserve. The analysis of morphology of the new phage allows us to conclude that it belongs to the family Siphoviridae.

Effect of microwave treatment for wine microbial stabilisation: Potential use of a Weibullian mathematical model

The aim of this research was to investigate the efficiency of microwaves (MW) for wine microbiological stabilization and thereby assess the potential application of a Weibullian mathematical model in wine industry. The study focused on (i) the influence of treatment time (come-up time and temperature maintenance) and temperature on a simple wine-like matrix, as well as (ii) the specific resistance of yeast and bacteria selected according to their representativeness in red wines (A. aceti ATCC_15973, S. cerevisiae FX10, B. bruxellensis CRBO_L0619 and AWRI_1499), and finally (iii) the potential usefulness of a new mathematical model adapted to heat treatment to evaluate strain sensitivity. This research aimed to show that microwave treatment decreases the main wine-associated microorganism populations and that the reduction in viable counts mainly depends on the MW treatment temperature. Complete microbiological stabilisation was obtained under a temperature of 50 °C a very short treatment time, except in the case of A. aceti ATCC_15973. Furthermore, the Weibull parameters analyses showed that heat inactivation a wine microorganism studied did not follow first-order kinetics, indicating that we should change our way of studying thermal death curves. The findings from this study suggest that MW could be useful for the wine industry as a complement or an alternative to sulphite utilisation.

Risk factors for healthcare-associated infections in newborns after surgery in a neonatal intensive care unit.

Health care-associated infections (HAIs) are a common cause of morbidity and mortality. There is little information on the risk factors associated with HAI in surgical newborns. To identify the risk factors associated with healthcare-associated infections in surgical newborns. Nested case-control study carried out during 2016-2017. Cases were newborns with healthcare-associated infections and controls were newborns without infection. Perinatal characteristics, use of antimicrobial prophylaxis, use of central venous catheter (CVC), mechanical ventilation, parenteral nutrition, age, and weight at the time of surgery, type of surgery, surgical wound classification, duration of surgery, number of surgical procedures, postsurgical HAIs and type of infection were registered. Univariate and multivariate analyses were performed. Seventy-one cases and 142 controls were included. The most frequent HAI was bloodstream infection (36.6%); the main microorganisms isolated in blood cultures were gram-positive cocci. Independent risk factors associated with HAIs in the multivariate analysis were CVC duration > 8 days (aOR = 17.2, 95% CI = 3.8-49.1), ≥ 2 surgeries (aOR = 16.5, 95% CI 5.8 -42.1) and abdominal surgery (aOR = 2.6, 95% CI = 1.2-6.6). Newborns undergoing surgery, mainly those with risk factors, require close monitoring during the postoperative period. CVC should be withdrawn as soon as possible.

The Antibacterial and Antifungal Capacity of Eight Commercially Available Types of Mouthwash against Oral Microorganisms: An In Vitro Study.

This work aimed to evaluate and compare the antimicrobial actions and effects over time of eight types of mouthwash, based on the impact of chlorhexidine on the main microorganisms that are responsible for oral diseases: Enterococcus faecalis, Pseudomonas aeruginosa, and Candida albicans. The mouthwashes' antimicrobial action was determined in terms of their minimum inhibitory concentration (MIC), minimum bactericidal/fungicidal concentration (MBC/MFC), and time-kill curves at different contact times (10 s, 30 s, 60 s, 5 min, 15 min, 30 min, and 60 min), against selected oral microorganisms. All the mouthwashes showed a notable effect against C. albicans (MICs ranging from 0.02% to 0.09%), and higher MIC values were recorded with P. aeruginosa (1.56% to >50%). In general, the mouthwashes showed similar antimicrobial effects at reduced contact times (10, 30, and 60 s) against all the tested microorganisms, except with P. aeruginosa, for which the most significant effect was observed with a long time (15, 30, and 60 min). The results demonstrate significant differences in the antimicrobial actions of the tested mouthwashes, although all contained chlorhexidine and most of them also contained cetylpyridinium chloride. The relevant antimicrobial effects of all the tested mouthwashes, and those with the best higher antimicrobial action, were recorded by A-GUM® PAROEX®A and B-GUM® PAROEX®, considering their effects against the resistant microorganisms and their MIC values.

Liver abscess due to Granulicatella adiacens in an immunocompetent patient: Case report

Pyogenic liver abscesses due to Granulicatella adiacens are infections associated with high mortality, mainly in immunocompromised patients. The main microorganisms associated with liver abscesses are Klebsiella pneumoniae, and Escherichia coli, though it may also be polymicrobial. However, case reports describing liver infection by Granulicatella adiacens are scarce.We present the case of an immunocompetent adult patient who presented 15 days of evolution consisting of quantified fever peaks associated with asthenia, adynamia, chills, jaundice and coluria. The initial clinical examination revealed a generalized icteric tint without abdominal pain, and blood pressure with a tendency to hypotension. Biliopancreatic confluent neoplasia, secondary cholangitis and sepsis of biliary origin were suspected, initiating fluid resuscitation and antibiotic therapy; blood cultures and complementary diagnostic studies were taken. Hepatobiliary ultrasound with evidence of an abscess of 73 x 62 mm in segment IV; the bile duct and pancreas were within normal limits. To better characterize the lesion evidenced in the liver, a contrast-enhanced computed tomography of the abdomen was performed. The patient completed antibiotic management with ciprofloxacin, vancomycin, and metronidazole in good condition and was successfully discharged.This is the first pyogenic liver abscess reported caused by Granulicatella adiacens in an immunocompetent patient, in whom early microbiological diagnosis in conjunction with targeted antibiotic treatment and percutaneous drainage of the lesion was decisive in the clinical outcome.

The rapid start-up of CANON process through adding partial nitration sludge to ANAMMOX system

This study aimed to start up the completely autotrophic nitrogen removal over nitrite (CANON) process after adding partial nitration (PN) sludge to the ANAMMOX reactor, so as to help the rapid start-up and stable operation of the CANON process in practical engineering applications. There were three steps in the research: cultivating the PN sludge, building a reliable ANAMMMOX system, and finally starting and running the CANON process. The PN sludge was successfully cultivated in less than 45 days with around 90% nitrite accumulation rate. The ANAMMOX reactor enriched a significant quantity of red granular sludge within 70 days, achieving the maximum nitrogen removal rate of 1.74 kg/(m3·d). Eventually, the CANON reactor was started up successfully, which achieved 95.08% of average ammonium removal efficiency and 84.51% of average total nitrogen removal efficiency in 60 days. The residual recalcitrant nitrite-oxidizing bacteria in the CANON process was successfully inhibited by intermittent aeration and 12 mg/L free ammonia in UASB reactor. Besides, Candidatus Kuenenia, Candidatus Brocadia and Nitrosomonas were the main functional microorganisms involved in the CANON process.

TRADITIONAL METHODS OF DIAGNOSING INFECTIOUS MASTITIS IN CATTLE

Infectious mastitis of cattle is the most common disease of dairy cattle, which causes significant economic losses due to reduced milk yield and poor milk quality. Etiological agents include a variety of gram-positive and gram-negative bacteria. In the winter or off-season, the main factor in the occurrence of mastitis is the contamination of the mammary gland with pathogenic microflora against the background of hypothermia. Infectious mastitis, as a rule, has a long subclinical form of manifestation and is characterized by the absence of clinical signs against the background of a high level of somatic cells. The occurrence of mastitis is facilitated by the development of pathogenic microorganisms. Due to the qualitative analysis of indicators of milk microflora, the main microorganisms that cause infectious mastitis were identified as S. epidermidis, S. aureus. S. uberis.
 During bacteriological studies, pure cultures of staphylococci, streptococci, and enterobacteria were isolated on selective and differential diagnostic media. In milk samples from patients with subclinical mastitis, representatives of the morphological group of fungi and mycoplasma were not isolated. The antibiotic sensitivity of the microflora in the milk samples of sick animals to gentamicin and amoxicillin and the false bactericidal effect to streptomycin, cefazolin, doxycycline and tetracycline, as well as the lack of sensitivity to penicillin, were established.

A novel gdmH-related gene, ghl, involved in environmental stress tolerance and vancomycin susceptibility in milk-derived Staphylococcus aureus

Staphylococcus aureus is one of the main microorganisms that contaminate dairy products and pickled foods, and has a great impact on economy and human health. GdmH-related proteins, as important functional units widely present in Staphylococcus species, have not been reported in S. aureus so far. In this study, we identified a gdmH-related gene, named ghl. We found that mutation of ghl gene could decrease the tolerance of environmental stresses (heat, desiccation, salt and hydrogen peroxide) of S. aureus and enhanced the capacities of biofilm formation. In addition, the ghl mutant was more sensitive to vancomycin on CAMHB solid plates but more resistant to vancomycin in CAMHB liquid medium compared to wild type RMSA24. These results indicated that ghl is an important factor to respond to environmental stress in foodborne S. aureus. This paper for the first time reported that a GdmH-related protein plays an important role in environmental tolerance, providing a new direction for the follow-up study of GdmH-related proteins, as well as a potential target gene for further research on the tolerance mechanism of Staphylococcus aureus in food processing and the control of biofilm formation.

METAGENOMIC ANALYSIS OF MICROBIAL CONSORTIUM GF-20 IN CORN STOVER DEGRADATION AT LOW TEMPERATURE

In our previous work, a microbial consortium GF-20 (Qinggeer et al., 2016) was enriched from compost habitats and adapted to efficiently and stably degrade corn stover under low temperatures. While the main microorganism and degradation-related functions and degradation-related coding enzyme genes of GF-20 were not clear. Therefore, the current study used the metagenomic to decipher the systematic and functional contexts within such microbial consortium under low temperatures. The results showed that the dominant functional microbials in GF-20 consortium were bacteria. The dominant phylums in GF-20 consortium were Proteobacteria (62.84%) and Bacteroidetes (10.24%). The dominant genus was Pseudomonas (50.84%), followed by Dysgonomonas (5.86%), Achromobacter (4.94%), Stenotrophomonas (3.67%) and Flavobacterium (2.04%). The metabolism was mainly composed of carbohydrate metabolism and amino acid metabolism, and included signal transduction, cell transport and other metabolic modes. The functional genes encoded were mainly distributed in glycosidolytic enzyme genes, and the functional enzymes were β-glucosidase, acetyl-CoA, pyruvate dehydrogenase and galactosidase. The GF-20 microbial consortium degraded the cellulose in corn stover primarily by β-glucosidase and endoglucanase, which were produced by 12 genera of microorganisms. The hemicellulose synergistic effect was produced by 15 genera of microorganisms including xylanase, xyloglucanase, mannolanase and branching enzyme.

Effects of different concentrations of butyrate on microbial community construction and metabolic pathways in anaerobic digestion

Investigating the effect of butyric acid concentration on anaerobic digestion systems in complex systems is important for the efficient degradation of butyric acid and improving the efficiency of anaerobic digestion. In this study, different loadings of butyric acid with 2.8, 3.2, and 3.6 g/(L·d) were added to the anaerobic reactor. At a high organic loading rate of 3.6 g/(L·d), methane was efficiently produced with VBP (Volumetric Biogas Production) of 1.50 L/(L·d) and biogas content between 65% and 75%. VFAs concentration remained below 2000 mg/L. Metagenome sequencing revealed changes in the functional flora within different stages. Methanosarcina, Syntrophomonas, and Lentimicrobium were the main and functional microorganisms. That the relative abundance of methanogens exceeded 35% and methanogenic metabolic pathways were increased indicated the methanogenic capacity of the system significantly improved. The presence of a large number of hydrolytic acid-producing bacteria also indicated the importance of the hydrolytic acid-producing stage in the system.

Translated article] Results of a preoperative screening and decolonization programme for Staphylococcus aureus in primary hip and knee arthroplasty

IntroductionDetection and decolonization of Staphylococcus aureus prior to surgery is postulated as an option to reduce the risk of infection in arthroplasties. The aim of this study was to evaluate the effectiveness of a screening programme for S. aureus in total knee arthroplasty (TKA) and total hip arthroplasty (THA), the incidence of infection with respect to a historical cohort, and its economic viability. Material and methodsPre-post intervention study in patients undergoing primary knee and hip prostheses in 2021, a protocol was carried out to detect nasal colonization by S. aureus and eradication if appropriate, with intranasal mupirocin, post-treatment culture with results three weeks between post-treatment culture and surgery. Efficacy measures are evaluated, costs are analyzed and the incidence of infection is compared with respect to a historical series of patients operated on between January and December 2019, performing a descriptive and comparative statistical analysis. ResultsThe groups were statistically comparable. Culture was performed in 89%, with 19 (13%) positive patients. Treatment was confirmed in 18, control culture in 14, all decolonized; none suffered infection. One culture-negative patient suffered from Staphylococcus epidermidis infection. In historical cohort: three suffered deep infection by S. epidermidis, Enterobacter cloacae, Staphylococcus aureus. The cost of the programme is €1661.85. ConclusionThe screening programme detected 89% of the patients. The prevalence of infection in the intervention group was lower than in the cohort, with S. epidermidis being the main micro-organism, different from S. aureus described in the literature and in the cohort. We believe that this programme is economically viable, as its costs are low and affordable.

Fertilization regimes and the nitrification process in paddy soils: Lessons for agricultural sustainability from a meta-analysis

Increasing evidence shows that fertilization plays a key role in improving nitrogen (N) storage and increasing N supply capacity in paddy soils. How fertilizer regimes (N application rate, substitution rate, and fertilizer type) and environmental variables (soil pH and SOM) affect N pools, nitrification processes (abundance of nitrifying microorganisms, nitrification rate), and N losses (NH3 volatilization and N2O emission) in paddy soils is still unclear. Here, we conducted a meta-analysis by compiling a total of 1307 individual experimental observations from 64 peer-reviewed publications to evaluate the impacts of N fertilization with other amendments (manure, biochar, or nitrification inhibitors) on the abovementioned paddy soil N sequestration and turnover. Overall, fertilization increased N pools (total N, NH4+-N, and NO3−-N content) and the abundance of main nitrifying microorganisms (AOA and AOB) by 7.3 % to 51.4 % and 70.3 % to 146.9 % in paddy soil, respectively, while stimulating NH3 volatilization and N2O emissions by 277.3 % and 149.7 %, respectively. The increased N losses following fertilization were positively correlated with the expansion of paddy soil N pools. In particular, the substitution of organic fertilizer for chemical fertilizer at 30 % to 70 % had a better effect on elevating soil N sequestration, while a substitution rate of >70 % reduced N losses. Moreover, the application of biochar and nitrification inhibitors was conducive to increasing total N, NH4+-N, and NH3 volatilization and reducing N2O emissions in fertilized paddy soils. Our findings indicated that fertilization regimes substantially stimulated N pools and N losses in paddy ecosystems. Thus, to avoid environmental and economic consequences, the optimization of N management and adjusting soil properties should be considered to increase N use efficiency and suppress N losses.

Preparation of Citrus reticulata peel nano-encapsulated essential oil and in vitro assessment of its biological properties.

Dental caries is the most common biofilm-dependent oral disease. Streptococcus mutans is among the main microorganisms responsible for the development of dental caries. Nano-suspension of Citrus reticulata (tangerine) peel essential oil in 0.5% (v/v) concentration was prepared and its antibacterial effect on S. mutans in planktonic and biofilm forms as well as its cytotoxic and antioxidant effects were assessed and compared with chlorhexidine (CHX). The minimum inhibitory concentration (MIC) of free essential oil, nano-encapsulated essential oil, and CHX was 5.6% (v/v), 0.0005% (v/v), and 0.0002% (w/v), respectively. The percentage of biofilm inhibition by the free essential oil, nano-encapsulated essential oil, and CHX at half-MIC was 67.3%, 24%, and 90.6%, respectively. The nano-encapsulated essential oil had no cytotoxicity and showed significant antioxidant effects in different concentrations. Nano-encapsulation of tangerine peel essential oil significantly enhanced its biological activities in much lower concentrations than the free essential oil (11,000 times diluted). It also showed lower cytotoxicity and higher antibiofilm effects in sub-MICs compared with CHX, indicating the optimal potential of tangerine nano-encapsulated essential oil for incorporation in the composition of organic antibacterial and antioxidant mouth rinses.

Antimicrobial Activity of Spices Popularly Used in Mexico against Urinary Tract Infections

Urinary tract infections (UTIs) are the most common infectious diseases worldwide. These infections are common in all people; however, they are more prevalent in women than in men. The main microorganism that causes 80-90% of UTIs is Escherichia coli. However, other bacteria such as Staphylococcus aureus, Enterococcus faecalis, Pseudomonas aeruginosa, Proteus mirabilis, and Klebsiella pneumoniae cause UTIs, and antibiotics are required to treat them. However, UTI treatment can be complicated by antibiotic resistance and biofilm formation. Therefore, medicinal plants, such as spices generally added to foods, can be a therapeutic alternative due to the variety of phytochemicals such as polyphenols, saponins, alkaloids, and terpenes present in their extracts that exert antimicrobial activity. Essential oils extracted from spices have been used to demonstrate their antimicrobial efficacy against strains of pathogens isolated from UTI patients and their synergistic effect with antibiotics. This article summarizes relevant findings on the antimicrobial activity of cinnamon, clove, cumin, oregano, pepper, and rosemary, spices popularly used in Mexico against the uropathogens responsible for UTIs.

Review: Quorum sensing mechanism between Streptococcus mutans and Candida albicans in the pathogenesis of dental caries

Background: Dental caries is one of the most common oral diseases that affects all age groups worldwide. Caries is a slow progressing chronic disease characterized by localized tooth decay. Caries arises from interactions on the tooth surface between microorganisms, microorganism products, host (saliva) and diet (sugar), which leads to the formation of pathogenic biofilms, or dental plaque, and causes tooth decay. Streptococcus mutans (S. mutans) bacteria are the main microorganisms that play a role in causing dental caries. The results of several clinical studies indicate that, apart from S. mutans, the fungus Candida albicans (C. albicans) is often detected in high numbers in caries. The existence of these two species in one biofilm allows the two species to communicate between cells which is called quorum sensing. Objective: To determine the Quorum sensing mechanism between S. mutans and C. albicans in the development of the pathogenesis of caries. Methods: 3 databases namely PUBMED, Web of Science and Scopus, were used to search for articles according to predetermined inclusion and exclusion criteria. Results: quorum sensing between S. mutans and C. albicans in the same biofilm can change gene expression in both species of microorganisms, as well as increase the growth of both species of microorganisms. Conclusion: Symbiosis between S. mutans and C. albicans in the oral cavity is very detrimental to humans because it can exacerbate the buildup of acid which results in caries.

Clinical factors associated with peripherally inserted central catheters (PICC) related bloodstream infections: a single centre retrospective cohort

BackgroundDespite their spread in daily practice, few data is available on clinical factors associated with peripherally inserted central catheter (PICC)-related bloodstream infections (PR-BSI). We aimed to assess the PR-BSI incidence, microbiology, and factors associated with PR-BSI with a focus on clinical symptoms.MethodsWe conducted a retrospective cohort study in a French university hospital. We screened all PICC insertions performed from April 1st, 2018, to April 1st, 2019, and included PICC insertions in adult patients. We assessed the PR-BSI incidence, the factors associated with PR-BSI using a Cox model, and negative and positive predictive values (NPVs and PPVs) of each clinical sign for PR-BSI.ResultsOf the 901 PICCs inserted in 783 patients (38,320 catheters days), 214 PICCs (24%) presented with a complication. The most prevalent complication was PR-BSI (1.9 per 1000 catheter days; 8.1% of inserted PICCs ). Enterobacterales (N = 27, 37%) and coagulase negative Staphylococci (N = 24, 33%), were the main microorganisms responsible for PR-BSI. Factors independently associated with occurrence of PR-BSI were fever (hazard ratio 13.21, 95% confidence interval 6.00–29.11, p < 0.001) and chills (HR 3.66, 95%CI 1.92–6.99, p < 0.001). All clinical signs and a duration of PICC maintenance ≥ 28 days, had a low PPVs (≤ 67.1%) but high NPVs (≥ 92.5%) for PR-BSI.ConclusionsMonitoring of clinical signs, especially fever and chills, with caution and limitation of device maintenance duration, could improve PICC management.

Shelf life modelling of kaşar cheese packaged with potassium sorbate, nisin, silver substituted zeolite, or chitosan incorporated active multilayer plastic films

The effects of active films on the stability of kaşar cheese stored at 5 °C, 15 °C, and 25 °C were investigated regarding microbial quality, physicochemical, and textural properties. The antimicrobials incorporated into the films (LDPE/polyamide/LDPE+2% antimicrobials) were potassium sorbate (PS-film), nisin (N-film), chitosan (CTS-film), or silver substituted zeolite (AgZeo-film). Shelf life, activation energy, and temperature quotient were also calculated. According to total mesophilic aerobic bacteria (TMAB) count, active films successfully inhibited microbial growth. The lowest growth rate for TMAB count of the samples was found in AgZeo-film, followed by N-film. CTS-film was more effective in controlling total yeast and mould count. PS-film showed some inhibition ability in both counts, but not as much as the other active films. Hence, antimicrobial agents incorporated into active films should be chosen considering main deteriorative microorganism in food being packaged. The active films improved shelf life of kaşar cheese by lasting the lag times of microorganisms.

Microbiology of bone-joint infections in children at a university clinic in Medellín, Colombia

Objective: the objective of the study was to describe the microorganisms, antimicrobial susceptibility, and diagnostic microbiology procedures in children with osteoarticular infections. Methods: This was a retro-prospective case series in children who consulted a university clinic in Medellín, Colombia, between 2010-2016, who had a cultureconfirmed diagnosis. Results: Out of a total of 218 registered patients, we included 39 with microbiological confirmation. There were more males (27; 69,2%), and 71% cases occurred in &gt;5 years old. The main microorganisms were Methicillin-Susceptible Staphylococcus aureus (MSSA) 53,8%, Methicillin-Resistant Staphylococcus aureus (MRSA) 20,5%, other gram-positive cocci 10%, Pseudomonas aeruginosa 5,1%, Enterobacter cloacae complex 2,5%, Haemophilus haemolyticus 2,5%, Mycobacterium tuberculosis 2,5%, and Candida albicans 2,5%. The susceptibility of MSSA/MRSA to trimethoprim-sulfamethoxazole and vancomycin was 100%, and for clindamycin it was 100% and 87%, respectively. Bone tissue and bone secretion using conventional methods, bone pus or synovial fluid inoculated in a blood culture bottle, and synovial tissue were positive in 96%, 87,5% and 50%, respectively. The blood cultures were positive in 54%. In two patients only the blood cultures were positive. Conclusion: MSSA was the most frequent microorganism followed by MRSA. However, MRSA showed high susceptibility to trimethoprim-sulfamethoxazole, clindamycin, and vancomycin. The high positivity of primary cultures suggests the importance of always obtaining them. Although the positivity of blood cultures was lower, should always be included as part of microbiological studies.