Genus-targeted markers for the taxonomic identification and monitoring of coagulase-positive and coagulase-negative Staphylococcus species.

The Staphylococcus genus comprises multiple pathogenic and opportunistic species that represent a risk to public health. Epidemiological studies require accurate taxonomic classification of isolates with enough resolution to distinguish clonal complexes. Unfortunately, 16 S rRNA molecular analysis and phenotypic characterization cannot distinguish all species and do not offer enough resolution to assess intraspecific diversity. Other approaches, such as Multilocus Sequence Tagging, provide higher resolution; however, they have been developed for Staphylococcus aureus and a few other species. Here, we developed a set of genus-targeted primers using five orthologous genes (pta, tuf, tpi, groEs, and sarA) to identify all Staphylococcus species within the genus. The primers were initially evaluated using 20 strains from the Collection of Microorganisms of Interest in Animal Health from AGROSAVIA (CMISA), and their amplified sequences were compared to a set of 33 Staphylococcus species. This allowed the taxonomic identification of the strains even on close species and the establishment of intraspecies diversity. To enhance the scope and cost-effectiveness of the proposed strategy, we customized the primer sets for an Illumina paired-end amplicon protocol, enabling gene multiplexing. We assessed five genes across 177 strains, generating 880 paired-end libraries from the CMISA. This approach significantly reduced sequencing costs, as all libraries can be efficiently sequenced in a single MiSeq run at a fraction (one-fourth or less) of the cost associated with Sanger sequencing. In summary, this method can be used for precise identification and diversity analysis of Staphylococcus species, offering an advancement over traditional techniques in both resolution and cost-effectiveness.

Co-resistance to methicillin and clindamycin among coagulase-negative staphylococci isolates recovered from pet food in Brazil.

Pet food have been considered as possible vehicles of bacterial pathogens. The sudden boom of the pet food industry due to the worldwide increase in companion animal ownership calls for pet food investigations. Herein, this study aimed to determine the frequency, antimicrobial susceptibility profile, and molecular characteristics of coagulase-negative staphylococci (CoNS) in different pet food brands in Brazil. Eighty-six pet food packages were screened for CoNS. All isolates were identified at species level by MALDI-TOF MS and species-specific PCR. Antimicrobial susceptibility testing was performed by disc diffusion and broth microdilution (vancomycin and teicoplanin only) methods. The D-test was used to screen for inducible clindamycin phenotype (MLS-B). SCCmec typing and detection of mecA, vanA, vanB, and virulence-encoding genes were done by PCR. A total of 16 (18.6 %) CoNS isolates were recovered from pet food samples. Isolates were generally multidrug-resistant (MDR). All isolates were completely resistant (100 %) to penicillin. Resistances (12.5 % - 75 %) were also observed for fluoroquinolones, sulfamethoxazole-trimethoprim, tetracycline, rifampicin, erythromycin, and tobramycin. Isolates were susceptible to vancomycin (MICs <0.25-1 µg/mL) and teicoplanin (MICs <0.25-4 µg/mL). Intriguingly, 3/8 (37.5 %) CoNS isolates with the ERYRCLIS antibiotype expressed MLS-B phenotype. All isolates harboured blaZ gene. Seven (43.8 %) isolates carried mecA; and among them, the SCCmec Type III was the most frequent (n = 5/7; 71.4 %). Isolates also harboured seb, see, seg, sej, sem, etb, tsst, pvl, and hla toxin virulence-encoding genes (6.3 % - 25 %). A total of 12/16 (75 %) isolates were biofilm producers, while the icaAB gene was detected in an S. pasteuri isolate. Herein, it is shown that pet food is a potential source of clinically important Gram-positive bacterial pathogens. To the best of our knowledge, this is the first report of MLS-B phenotype and MR-CoNS in pet food in Latin America.

Methicillin-resistant Staphylococcus aureus and coagulase-negative Staphylococcus produce antimicrobial substances against members of the skin microbiota in children with atopic dermatitis.

Coagulase-negative Staphylococcus (CoNS) species inhibiting Staphylococcus aureus has been described in the skin of atopic dermatitis (AD) patients. This study evaluated whether Staphylococcus spp. from the skin and nares of AD and non-AD children produced antimicrobial substances (AMS). AMS production was screened by an overlay method and tested against NaOH, proteases and 30 indicator strains. Clonality was assessed by pulsed-field gel electrophoresis. Proteinaceous AMS-producers were investigated for autoimmunity by the overlay method and presence of bacteriocin genes by polymerase chain reaction. Two AMS-producers had their genome screened for AMS genes. A methicillin-resistant S. aureus (MRSA) produced proteinaceous AMS that inhibited 51.7% of the staphylococcal indicator strains, and it was active against 60% of the colonies selected from the AD child where it was isolated. On the other hand, 57 (8.8%) CoNS from the nares and skin of AD and non-AD children, most of them S. epidermidis (45.6%), reduced the growth of S. aureus and other CoNS species. Bacteriocin-related genes were detected in the genomes of AMS-producers. AMS production by CoNS inhibited S. aureus and other skin microbiota species from children with AD. Furthermore, an MRSA colonizing a child with AD produced AMS, reinforcing its contribution to dysbiosis and disease severity.

Methicillin-Resistant Staphylococcus aureus and Coagulase-Negative Staphylococcus from School Dining Rooms in Argentina.

Methicillin-resistant Staphylococcus aureus (MRSA) constitutes an important cause for concern in the field of public health, and the role of the food chain in the transmission of this pathogen and in antimicrobial resistance (AMR) has not yet been defined. The objectives of this work were to isolate and characterize coagulase-positive Staphylococcus (CoPS) and coagulase-negative Staphylococcus (CoNS), particularly S. aureus, from school dining rooms located in Argentina. From 95 samples that were obtained from handlers, inert surfaces, food, and air in 10 establishments, 30 Staphylococcus strains were isolated. Four isolates were S. aureus, and the remaining ones (N = 26) belonged to 11 coagulase-negative species (CoNS). The isolates were tested for susceptibility to nine antibiotics. The presence of genes encoding toxins (luk-PV, sea, seb, sec, sed, and see), adhesins (icaA, icaD), and genes that confer resistance to methicillin (mecA) and vancomycin (vanA) was investigated. The resistance rates measured for penicillin, cefoxitin, gentamicin, vancomycin, erythromycin, clindamycin, levofloxacin, trimethoprim-sulfamethoxazole, and tetracycline were 73%, 30%, 13%, 3%, 33%, 17%, 13%, 7%, and 7% of the isolates, respectively. Seventeen AMR profiles were detected, and 11 isolates were multidrug resistant (MDR). Seven methicillin-resistant Staphylococcus isolates were detected in the hands of handlers from four establishments, two of them were MRSA. Two S. aureus isolates presented icaA and icaD, another one, only icaD. The gene vanA was found in two isolates. In relation to S. aureus, resistance to vancomycin but not to gentamicin was detected. School feeding plays a key role in the nutrition of children, and the consumption of food contaminated with MRSA and vancomycin-resistant S. aureus (VRSA) can be a serious threat to health. In particular, it was detected that the handlers were the source of MRSA, VRSA, MR-CoNS (methicillin-resistant coagulase-negative Staphylococcus), and MDR isolates. The results obtained indicate that the vigilance of this pathogen in school dining rooms should be extreme.

Acute splenic sequestration in HbSS: observations from the Jamaican birth cohort.

OBJECTIVE: To document the prevalence, clinical features, haematology and outcome of acute splenic sequestration (ASS) in homozygous sickle cell disease (HbSS). STUDY DESIGN: A cohort study from birth. SETTING: The Medical Research Council Laboratories at the University of the West Indies, Kingston, Jamaica. PATIENTS: 311 cases of HbSS detected during the screening of 100 000 deliveries at the main government maternity hospital between 1973 and 1981. INTERVENTIONS: Long-term follow-up and free patient care focusing on ASS. MAIN OUTCOME MEASURE: Acute splenic sequestration. RESULTS: There were 183 episodes of ASS in 105 patients representing 35% of the cohort. The median age for first event was 1.07 years. During ASS, median values for haemoglobin fell by 32 g/dL, reticulocytes increased by 8% and total nucleated cells increased by 10.5%. ASS recurred in 47 (45%) patients. Conservative therapy in 133 episodes of 85 patients was associated with five deaths and splenectomy in 20 patients with 50 episodes had no deaths. Symptoms were generally non-specific but acute chest syndrome occurred in 17, and blood cultures revealed coagulase negative staphylococci in 5. The ASS case fatality rate was 3.6% and may be higher if autopsy evidence of ASS is included. There was no seasonal pattern but higher levels of fetal haemoglobin predicted patients less prone to ASS and its later occurrence. CONCLUSIONS: ASS remains an important cause of morbidity and mortality in HbSS in developing societies. ASS appears to be a non-specific response to many possible risk factors including coagulase negative staphylococci.

Presence and Resistance Profile of Staphylococcus spp. Isolated from Slaughtered Pigs.

Background: The objective of this study was to isolate Staphylococcus spp. and to characterize the resistance profile in nasal samples from pigs slaughtered for consumption. Material and Methods: Intranasal swabs were collected from 100 pigs immediately after bleeding in a slaughterhouse located in the largest pork production region in Brazil, these samples were cultured and isolated to identify Staphylococcus spp. in coagulase positive (CoPS) and coagulase negative (CoNS) and molecular identification of Staphylococcus aureus and then subjected to the disk-diffusion test to identify the bacterial resistance profile and search for the mecA gene. Results: Of the 100 samples collected, it was possible to isolate 79 Staphylococcus spp., of these, 72.15% were classified as CoNS and 27.85% of the isolates classified as CoPS. Among the CoPS isolates, 77.27% were identified as S. aureus. Through the disk-diffusion test, it was possible to verify isolates resistant to clindamycin and erythromycin (98.73%), chloramphenicol (93.67%), and doxycycline (89.87%). There was amplification of the mecA gene in 30.38% of Staphylococcus spp. Conclusion: The results of this study highlight the need for the careful use of antibiotics in swine production, in addition to aiming at continuous surveillance in relation to the rate of multiresistant microorganisms within these environments, focused on large industrial centers; such results also indicate the importance of understanding, through future studies, possible pathways to transmission of these microorganisms directly, or indirectly, through meat products derived from these pigs, which can be considered neglected diffusers of variants of Staphylococcus spp. resistant to antibiotics or carriers of important resistance genes related to One Health.

Biogenic silver nanoparticles: in vitro activity against Staphylococcus aureus methicillin-resistant (MRSA) and multidrug-resistant coagulase-negative Staphylococcus (CoNS).

Multidrug-resistant (MDR) bacteria are one problem in health since the therapeutic alternative are reduced. For this, the application of nanotechnology through functionalized nanoparticles, like a biogenic silver nanoparticle (Bio-AgNP), obtained by biological synthesis, emerges as a possible alternative against the MDR bacteria. This study aimed to evaluate the antibacterial and antibiofilm activity of Bio-AgNP obtained for biological synthesis by Fusarium oxysporum strain 551 against methicillin-resistant Staphylococcus aureus (MRSA) and MDR coagulase-negative Staphylococcus (CoNS) isolates. Bio-AgNP has activity against S. aureus ATCC 25904, Staphylococcus epidermidis ATCC 35984, and MDR isolates, with minimal inhibitory concentration (MIC) ranging from 3.75 to 15 µg.mL-1 and minimal bactericidal concentration (MBC) from 7.5 to 30 µg.mL-1. In the membrane leakage assay, it was observed that all concentrations tested led to proteins release from the cellular content dose-dependently, where the highest concentrations led to higher protein in the supernatant. The 2×MIC of Bio-AgNP killed ATCC 35984 after 6h of treatment, and ATCC 25904 and S. aureus (SA3) strains after 24h of treatment. The 4×MIC was bactericidal in 6h of treatment for all strains in the study. The biofilm of MDR isolates was inhibited in 80.94 to 100% and eradicated in 60 to 94%. The confocal laser scanning microscopy (CLSM) analysis demonstrated similar results to the antibiofilm assays. The Bio-AgNP has antibacterial and antibiofilm activity and can be a promising therapeutic alternative against MDR bacteria.

Detection and expression of SapS, a class C nonspecific acid phosphatase with O-phospho-Ltyrosine- phosphatase activity, in Staphylococcus aureus isolates from patients with chronic osteomyelitis / Detección y expresión de SapS, una fosfatasa ácida no específica de clase C con actividad de fosfatasa O-fosfotirosina, en aislamientos de Staphylococcus aureus de pacientes con osteomielitis crónica

INTRODUCTION: The identity of Staphylococcus aureus virulence factors involved in chronic osteomyelitis remains unresolved. SapS is a class C non-specific acid phosphatase and a well-known virulence factor that has been identified in S. aureus strain 154 but in protein extracts from rotting vegetables. OBJECTIVE: To identify the SapS gene and characterize the activity of SapS from S. aureus strains: 12 isolates from bone infected samples of patients treated for chronic osteomyelitis and 49 from a database with in silico analysis of complete bacterial genomes. MATERIALS AND METHODS: The SapS gene was isolated and sequenced from 12 S. aureus clinical isolates and two reference strains; 49 S. aureus strains and 11 coagulase-negative staphylococci were tested using in silico PCR. Culture media semi-purified protein extracts from the clinical strains were assayed for phosphatase activity with p-nitro-phenylphosphate, O-phospho-L-tyrosine, O-phospho-L-serine, and OphosphoL-threonine in conjunction with various phosphatase inhibitors. RESULTS: SapS was detected in the clinical and in-silico S. aureus strains, but not in the in silico coagulase-negative staphylococci strains. Sec-type I lipoprotein-type N-terminal signal peptide sequences; secreted proteins, and aspartate bipartite catalytic domains coding sequences were found in the SapS nucleotide and amino acid sequence analysis. SapS dephosphorylated with p-nitro-phenyl-phosphate and ophosphoLtyrosine were selectively resistant to tartrate and fluoride, but sensitive to vanadate and molybdate. CONCLUSION: SapS gene was found in the genome of the clinical isolates and the in silico Staphylococcus aureus strains. SapS shares biochemical similarities with known virulent bacterial, such as protein tyrosine phosphatases, suggesting it may be a virulence factor in chronic osteomyelitis.

Introducción: Se desconoce la identidad de los factores de virulencia de Staphylococcus aureus implicados en la osteomielitis crónica. Sin embargo, SapS, una fosfatasa ácida no específica de clase C, es un factor de virulencia reconocido y ya fue identificada en la cepa 154 de S. aureus, pero en extractos proteicos de vegetales podridos. Objetivo: Detectar el gen SapS y caracterizar la actividad de la fosfatasa SapS en cepas de S. aureus aisladas de pacientes con osteomielitis crónica y en las reportadas en una base de datos de análisis in silico de genomas bacterianos completos. Materiales y métodos: Se aisló y secuenció el gen SapS en los 12 aislamientos clínicos de S. aureus y en dos cepas de referencia; estas secuencias se analizaron junto con las secuencias de las cepas reportadas en la base de datos de genomas bacterianos: 49 cepas de S. aureus y 11 cepas de estafilococos negativos para coagulasa. Se evalúo la actividad de la fosfatasa SapS, presente en los extractos de los sobrenadantes de los cultivos de las cepas clínicas, mediante la hidrólisis de fosfato p-nitrofenil, O-fosfo-Ltirosina, O-fosfo-L serina y O-fosfo-L treonina junto con varios inhibidores de fosfatasas. Resultados: Se detectó el gen SapS en el genoma de las cepas clínicas y en las 49 cepas de S. aureus analizadas in silico, pero no en las 11 cepas de estafilococos negativos para coagulasa. La secuenciación de SapS reveló un péptido señal presente en el extremo N-terminal de proteínas extracelulares y los dominios bipartitos de aspartato (DDDD) en su sitio catalítico. SapS hidroliza selectivamente el fosfato p-nitrofenil y la O-fosfo-L-tirosina, pero es sensible a vanadato y molibdato. Conclusión: Se encontró SapS en el genoma de S. aureus de las cepas clínicas y de las cepas de simulación computacional. La SapS con actividad específica para la hidrólisis de la O-fosfo-L-tirosina comparte similitudes bioquímicas con las fosfatasas-tirosina bacterianas, por lo que puede formar parte de la red de factores de virulencia de la osteomielitis crónica.

Microbiological monitoring of coagulase-negative Staphylococcus in public drinking water fountains: Pathogenicity factors, antimicrobial resistance and potential health risks.

The presence of opportunistic bacteria such as coagulase-negative Staphylococcus (CoNS) in drinking water poses public health concerns because of its potential to cause human infection and due to its antimicrobial resistance (AMR) diversity. This study evaluated the occurrence, virulence markers and AMR of CoNS in 468 drinking water samples from 15 public fountains located in four urban parks of São Paulo city (Brazil). Out of 104 samples positive for the presence of Staphylococcus genus, we detected CoNS in 75 of them (16%), which did not meet the Brazilian sanitary standards for residual chlorine. All isolates were of concern to public health for being responsible for infection in humans from low to high severity, nine of them are considered the most of concern due to 63.6% being multiresistant to antimicrobials. The results demonstrated that CoNS in drinking water must not be neglected. It is concluded that the presence of resistant staphylococci in drinking water is a potential health risk, which urges feasible and quick control measures to protect human health, especially in crowded public places.

Mucoid Staphylococcus haemolyticus: an unheeded multidrug-resistant pathogen.

Coagulase-negative Staphylococci (CoNS) are among the most abundant members of human skin microbiome. CoNS have lately been recognized as substantial agents in plethora of infections, especially nosocomial infections in preterm infants and immunocompromised patients. Staphylococcus haemolyticus is the second most common species isolated from blood, and identification is further hindered when there is a deviation in morphology from the classical one. Here, we report an uncommon case of multidrug resistant mucoid S. hemolyticus isolated from blood in a patient of polytrauma. The patient was managed with ceftriaxone-sulbactam, gentamicin, and meropenem as empirical therapy, which was subsequently changed to intravenous vancomycin. The patient showed favorable response to treatment. Mucoid isolates are known to be more virulent and multi-drug resistant than the classical morphotypes. We also conducted systematic review to decipher the prevalence of mucoid S. hemolyticus and linezolid (LZD) resistance in the same. This case highlights the significance of awareness of mucoid phenotypes of Gram-positive cocci for clinical microbiologists to reach accurate identification. Resistance to LZD further underscores the need of restriction policies in hospitals and to roll out antimicrobial stewardship program stringently, so that the growing resistance could be contained.

Presence of Staphylococcus spp. carriers of the mecA gene in the nasal cavity of piglets in the nursery phase.

The presence of Staphylococcus spp. resistant to methicillin in the nasal cavity of swine has been previously reported. Considering the possible occurrence of bacterial resistance and presence of resistance genes in intensive swine breeding and the known transmissibility and dispersion potential of such genes, this study aimed to investigate the prevalence of resistance to different antibiotics and the presence of the mecA resistance gene in Staphylococcus spp. from piglets recently housed in a nursery. For this, 60 nasal swabs were collected from piglets at the time of their housing in the nursery, and then Staphylococcus spp. were isolated and identified in coagulase-positive (CoPS) and coagulase-negative (CoNS) isolates. These isolates were subjected to the disk-diffusion test to evaluate the bacterial resistance profile and then subjected to molecular identification of Staphylococcus aureus and analyses of the mecA gene through polymerase chain reaction. Of the 60 samples collected, 60 Staphylococcus spp. were isolated, of which 38 (63.33%) were classified as CoNS and 22 (36.67%) as CoPS. Of these, ten (45.45%) were identified as Staphylococcus aureus. The resistance profile of these isolates showed high resistance to different antibiotics, with 100% of the isolates resistant to chloramphenicol, clindamycin, and erythromycin, 98.33% resistant to doxycycline, 95% resistant to oxacillin, and 85% resistant to cefoxitin. Regarding the mecA gene, 27 (45%) samples were positive for the presence of this gene, and three (11.11%) were phenotypically sensitive to oxacillin and cefoxitin. This finding highlights the importance of researching the phenotypic profile of resistance to different antimicrobials and resistance genes in the different phases of pig rearing to identify the real risk of these isolates from a One Health perspective. The present study revealed the presence of samples resistant to different antibiotics in recently weaned production animal that had not been markedly exposed to antimicrobials as growth promoters or even as prophylactics. This information highlights the need for more research on the possible sharing of bacteria between sows and piglets, the environmental pressure within production environments, and the exposure of handlers during their transport, especially considering the community, hospital, and political importance of the presence of circulating resistant strains.

Resistance profile and biofilm production capacity of Staphylococcus spp. beef slaughterhouse isolates and their sensitivity to Rosmarinus officinalis essential oil.

Microorganisms can interfere with meat quality, being a public health problem. The aim of this study was to characterize the antimicrobial susceptibility profile of Staphylococcus spp. isolated from utensils of a bovine slaughterhouse and to evaluate the antibacterial and antibiofilm activity of the essential oil of Rosmarinus officinalis L. (rosemary). Samples of surfaces and utensils used during slaughter in the northwest of the state of Paraná, Brazil were collected. After isolation and differentiation of the isolates by the coagulase test, the antimicrobial susceptibility test, Staphylococcus aureus identification and mecA gene research were performed. The study for biofilm production was carried out by the method of adhesion in borosilicate tube and by adhesion in polystyrene plate. Subsequently, the inhibitory activity of the R. officinalis essential oil and its ability to inhibit biofilm were investigated. Twenty-two of the samples collected were identified as coagulase-negative Staphylococcus and five as coagulase-positive Staphylococcus. There was resistance to all antibiotics tested, with clindamycin (33.33%) and rifampicin (29.6%) showing the highest rate. None of the samples was confirmed as Staphylococcus aureus or for the presence of the mecA resistance gene. The essential oil inhibited the growth of 48% of the isolates at a concentration of 16,000 µg/mL. Of these isolates, 33% were positive for biofilm production and this biofilm was also inhibited by the essential oil. This work revealed that multidrug-resistant Staphylococcus and biofilm producers are present in the slaughter environment and are susceptible to the essential oil of R. officinalis.

Vancomycin heteroresistance among methicillin-resistant clinical isolates S. haemolyticus, S. hominis, S. simulans, and S. warneri.

Besides being an essential part of the skin microbiome, coagulase-negative staphylococci are the etiological factors of serious infections. The aim of the study was to evaluate the heteroresistance to vancomycin and the potential antimicrobial efficacy of teicoplanin and daptomycin against the multiresistant strains of S. haemolyticus, S. hominis, S. warneri, and S. simulans. The study covered 80 clinical coagulase-negative staphylococci. Teicoplanin, vancomycin, and daptomycin MICs for the tested strains were determined according to EUCAST recommendation. The vanA and vanB genes were searched. The brain heart infusion screen agar method detected vancomycin heteroresistance. The population analysis profile method and analysis of autolytic activity were applied for the strains growing on BHI containing 4 mg/L vancomycin. Seven S. haemolyticus, two S. hominis, and two S. warneri strains presented a heterogeneous resistance to vancomycin. Their subpopulations were able to grow on a medium containing 4-12 mg/L of vancomycin. Monitoring heteroresistance to peptide antibiotics, which are often the last resort in staphylococcal infections, is essential due to the severe crisis in antibiotic therapy and the lack of alternatives to treat infections with multiresistant strains. Our work highlights the selection of resistant strains and the need for more careful use of peptide antibiotics.

[Staphylococcus lugdunensis infection: report of 44 cases]. / Infección por Staphylococcus lugdunensis: descripción de 44 casos.

BACKGROUND: Staphylococcus lugdunensis is a coagulase-negative staphylococcus (CNS) with virulence and antibiotic sensitivity characteristics which makes it more similar to Staphylococcus aureus than other CNS. AIM: To know the microbiological and clinical characteristics of S. lugdunensis isolates identified from our health sector. METHODS: A retrospective study of S. lugdunensis isolates was carried out between 2017 and 2019 in the Microbiology Service of the San Jorge University Hospital in Huesca (Spain). The clinical records of patients with S. lugdunensis isolation were reviewed, considering the following factors: age, sex, sample type, service and underlying disease. Bacterial identification was performed using MALDI-TOF VITEK MS (BioMérieux, France). The pattern of antibiotic susceptibility was studied by means of plate microdilution. RESULTS: 44 isolates of S. lugdunensis were obtained: 12 corresponded to wounds, 10 were abscesses, 8 ulcers, 7 urine samples, 4 skin smears, 2 otic exudates, and 1 vaginal exudate. Regarding the underlying disease, five patients had a tumor processes and ten had diabetes mellitus. In 17 patients there was a history of recent surgery or trauma. Most of the strains were susceptible to the antibiotics studied. Production of beta-lactamase was observed in 19 of them, two were resistant to macrolides and three to clindamycin. None of the isolates were resistant to oxacillin, gentamicin or cotrimoxazole. CONCLUSIONS: Although S. lugdunensis maintains a good sensitivity to most antibiotics, its tendency to produce abscesses and that it expresses virulence factors more similar to S. aureus than to other CNS requires a correct identification in the laboratory so that its incidence is not underestimated.

Infección por Staphylococcus lugdunensis: descripción de 44 casos / Staphylococcus lugdunensis infection: report of 44 cases

INTRODUCCIÓN: Staphylococcus lugdunensis, es un estafilococo coagulasa negativa (SCN) con características de virulencia y de sensibilidad antimicrobiana que lo hacen más parecido a Staphylococcus aureus que a otros SCN. OBJETIVOS: Conocer las características clínicomicrobiológicas de los aislados de S. lugdunensis identificados en nuestra institución. MATERIAL Y MÉTODOS: Se realizó un estudio retrospectivo de los aislados de S. lugdunensis entre los años 2017 y 2019 en el Servicio de Microbiología del Hospital Universitario San Jorge de Huesca (España). Se revisaron las historias clínicas correspondientes a los pacientes con aislamiento de S. lugdunensis, considerándose las siguientes variables: edad, sexo, tipo de muestra, servicio de procedencia y enfermedad de base. La identificación bacteriana se realizó con MALDI-TOF VITEK MS (BioMérieux, Francia). Así mismo, se estudió su patrón de susceptibilidad antimicrobiana in vitro mediante microdilución en placa. RESULTADOS: Se obtuvieron 44 aislados de S. lugdunensis: 12 procedían de heridas, 10 fueron abscesos, 8 úlceras, 7 orinas, 4 frotis cutáneos, 2 exudados óticos, y 1 exudado vaginal. En relación con la enfermedad de base destacaron cinco pacientes con procesos tumorales y diez con diabetes mellitus. En 17 pacientes existían antecedentes de cirugía o traumatismo reciente. La mayoría de las cepas fueron sensibles a los antimicrobianos estudiados. En 19 de ellas se observó producción de β-lactamasa, dos fueron resistentes a macrólidos y tres a clindamicina. Todas las cepas fueron sensibles a oxacilina, gentamicina y cotrimoxazol. CONCLUSIONES: Aunque S. lugdunensis mantiene una buena sensibilidad a la mayoría de los antimicrobianos, su tendencia a producir abscesos y que exprese factores de virulencia más parecido a S. aureus que a otros SCN, hace necesaria una correcta identificación en el laboratorio con el fin de que su incidencia no quede subestimada.

BACKGROUND: Staphylococcus lugdunensis is a coagulase-negative staphylococcus (CNS) with virulence and antibiotic sensitivity characteristics which makes it more similar to Staphylococcus aureus than other CNS. AIM: To know the microbiological and clinical characteristics of S. lugdunensis isolates identified from our health sector. METHODS: A retrospective study of S. lugdunensis isolates was carried out between 2017 and 2019 in the Microbiology Service of the San Jorge University Hospital in Huesca (Spain). The clinical records of patients with S. lugdunensis isolation were reviewed, considering the following factors: age, sex, sample type, service and underlying disease. Bacterial identification was performed using MALDI-TOF VITEK MS (BioMérieux, France). The pattern of antibiotic susceptibility was studied by means of plate microdilution. RESULTS: 44 isolates of S. lugdunensis were obtained: 12 corresponded to wounds, 10 were abscesses, 8 ulcers, 7 urine samples, 4 skin smears, 2 otic exudates, and 1 vaginal exudate. Regarding the underlying disease, five patients had a tumor processes and ten had diabetes mellitus. In 17 patients there was a history of recent surgery or trauma. Most of the strains were susceptible to the antibiotics studied. Production of beta-lactamase was observed in 19 of them, two were resistant to macrolides and three to clindamycin. None of the isolates were resistant to oxacillin, gentamicin or cotrimoxazole. CONCLUSIONS: Although S. lugdunensis maintains a good sensitivity to most antibiotics, its tendency to produce abscesses and that it expresses virulence factors more similar to S. aureus than to other CNS requires a correct identification in the laboratory so that its incidence is not underestimated.

Avaliação microbiológica de sorvetes comercializados na cidade de Pouso Alegre - MG / Microbiological evaluation of ice cream sold in the city of Pouso Alegre - MG

O presente estudo teve como objetivo avaliar a qualidade microbiológica de sorvetes comercializados na cidade de Pouso Alegre ­ MG. Foram adquiridas 2 amostras de sorvete de 18 sorveterias em um intervalo de 30 dias totalizando 36 amostras. As amostras de sorvetes foram submetidas às análises para enumeração de coliformes totais, coliformes termotolerantes, Estafilococos coagulase positiva e Salmonella spp. As análises foram realizadas segundo os protocolos da American Public Health Association descrita no Compendium of methods for the microbiological examination of foods. Neste estudo não foram encontradas espécies de Salmonella spp. entretanto, houve amostras contaminadas por E. coli e Estafilococos coagulase positiva.13,89% das amostras analisadas estavam fora dos padrões estabelecidos. Verificou-se ainda a presença de coliformes totais em 77,78% e de Staphylococcus sp. em 36,11% e, embora a legislação vigente não mencione limites de contaminação para estes microrganismos, pode-se dizer que a matéria-prima estava contaminada, que as condições higiênicas, no processamento e armazenamento estavam inadequados para este produto. As amostras analisadas obtidas de sorveterias da região central foram as mais contaminadas, onde foi encontrada a presença de E. coli e Estafilococos coagulase positiva. A presença desses microrganismos sugere falhas em algum momento do processamento, armazenamento ou da venda destes produtos tornando-os inadequados, podendo não só causar uma deterioração mais rápida do sorvete, mas também colocando em risco a saúde do consumidor.(AU)

This study aimed to evaluate the microbiological quality of ice cream sold in the city of Pouso Alegre ­ MG. Two ice cream samples were acquired from 18 ice cream parlors in a 30-day interval, totaling 36 samples. The ice cream samples were subjected to analysis for enumeration of total coliforms, thermotolerant coliforms, coagulase positive Staphylococci and Salmonella spp. The analyzes were performed according to the protocols of the American Public Health Association described in the Compendium of Methods for the Microbiological Examination of Foods. In this study no species of Salmonella spp. were found, however, there were samples contaminated by E. coli and coagulase positive Staphylococci. 13.89% of the analyzed samples were outside the established standards. It was also verified the presence of total coliforms in 77.78% and Staphylococcus sp. in 36.11% and, although the current legislation does not mention contamination limits for these microorganisms, it can be said that the raw material was contaminated, that the hygiene, processing and storage conditions were inadequate for this product. The analyzed samples obtained from ice cream parlors in the central region were the most contaminated, where the presence of E. coli and coagulase positive Staphylococci was found. The presence of these microorganisms suggests failures at some point in the processing, storage or sale of these products, making them unsuitable and not only causing a faster deterioration of the ice cream, but also putting the consumer's health at risk.(AU)

Avaliação da qualidade microbiológica do queijo de coalho comercializado na praia de Copacabana - RJ / Evaluation of the microbiological quality of coalho cheese commercialized on Copabacabana beach

A pesquisa teve o objetivo de avaliar as condições higiênicas e sanitárias de comercialização do queijo de coalho por vendedores ambulantes na praia de Copacabana, por meio de inspeção visual e análises microbiológicas. Para o estudo foram coletadas quinze amostras de cinco diferentes ambulantes e estas foram encaminhadas para o Centro Estadual de Pesquisa em Qualidade de Alimentos da Empresa de Pesquisa Agropecuária do Estado do Rio de Janeiro (PESAGRO-RIO/CEPQA) onde foram submetidas às análises microbiológicas. O resultado da avaliação visual das condições higiênico-sanitárias demonstrou 100% de não conformidades em relação à adoção das Boas Práticas de Fabricação por parte dos manipuladores. Os resultados das contagens de Estafilococos coagulase positiva e de Coliformes termotolerantes se apresentaram acima do limite preconizado pela legislação vigente em 75% e 6,7% das amostras respectivamente. Em 25% das amostras foi verificada a presença de Salmonella spp. O estudo demonstrou que o queijo de coalho vendido por ambulantes da praia de Copacabana estava impróprio para o consumo podendo representar risco à saúde dos consumidores.(AU)

The research aimed to evaluate the hygienic and sanitary commercialized conditions of coalho cheese by street vendors on Copacabana beach, through visual inspection and microbiological analysis. For conducting the study, fifteen samples were collected from five different street vendors and these were analyzed at the State Center for Research in Food Quality of the Agriculture Research Company of the State of Rio de Janeiro (PESAGRO-RIO/CEPQA). The result of the visual assessment of hygienic-sanitary conditions demonstrated 100% of non-conformities in relation to the adoption of Good Manufacturing Practices by the manipulators. In counts of coagulase positive Staphylococcus and Thermotolerant Coliforms were above the limit recommended by the current legislation in 75% and 6.7% of the samples, respectively. Salmonella spp. was present in 25% of the analyses.The study showed that the coalho cheese sold by street vendors on Copacabana beach was unfit for consumption and could pose a risk to consumer health.(AU)

Factors associated with multidrug-resistant bacteria in healthcare-associated infections: a pediatric intensive care unit case-control study.

OBJECTIVE: To investigate the prevalence of factors related to healthcare-associated infections, caused by multidrug-resistant bacteria, in a pediatric intensive care unit. METHODS: A retrospective case-control study conducted from January 1, 2007 to December 31, 2018, in São Paulo (SP), Brazil. The study was carried out at the pediatric intensive care unit of a high-complexity, tertiary care general hospital. The study included patients aged 1 month to 19 years, admitted to the pediatric intensive care unit, diagnosed as healthcare-associated infections. RESULTS: There was significant evidence of infection by multidrug-resistant bacteria associated with immunosuppressed patients (p<0.001), in whom the likelihood of multidrug-resistant bacteria infection was estimated to be nine-fold higher than among non-immunosuppressed patients (OR 8.97; 95%CI 2.69-29.94). In the analysis of multiple logistic regression model, we observed that immunosuppressed patients had an 8.5-fold higher chance of multidrug-resistant bacteria infection when compared to non-immunosuppressed patients (OR 8.48; 95%CI 2.54-28.35; p=0.001). There is evidence of association between the Case Group and presence of Gram-positive (p=0.007), coagulase-negative Staphylococcus (p<0.001), and Gram-negative (p=0.041) microorganisms. CONCLUSION: The immunocompromised-state variable is a factor related to healthcare-associated infections caused by multidrug-resistant bacteria, and the Case Group presented higher proportions of Gram-positive microorganisms and coagulase-negative Staphylococcus.

Occurrence and Distribution of Antibiotic-Resistant Staphylococcus aureus in a Brazilian Pork Production Chain.

ABSTRACT: Here we characterized the distribution and the antibiotic resistance of staphylococci from a Brazilian pork production chain. Samples (n = 1,114) from pig farms, pig lots, and slaughterhouses, located in two Brazilian states (Minas Gerais and Paraná), were subjected to coagulase-positive Staphylococcus enumeration. S. aureus isolates (n = 251) from this collection were further characterized for their resistance to oxacillin, cefoxitin, vancomycin, and tetracycline through phenotypic and molecular assays. Coagulase-positive Staphylococcus counts from pig farms were higher compared with other samples (P < 0.05). Other counts were relatively low but were present in all production stages. S. aureus isolates were commonly resistant to oxacillin and cefoxitin (54 of 73, 74.0%), qualifying them as methicillin-resistant S. aureus, but PCR assays indicated that few harbored the expected antimicrobial resistance genes (femB, mecA, and mecC). Lower frequencies of vancomycin and tetracycline resistance were found (6.8 to 37.0%). PCR sensitivity (34.5 to 86.7%) and specificity (26.6 to 85.0%) for detection of antibiotic resistance genes varied based on the assessed antibiotic. Antibiotic-resistant staphylococci are widely distributed in the Brazilian pork production chain, and methicillin-resistant S. aureus can become a potential health and economic impediment for the Brazilian pork industry.

Characterization and antimicrobial susceptibility of coagulase-positive Staphylococcus isolated in a veterinary teaching hospital in Chile.

There is limited information about the prevalence and antimicrobial susceptibility of coagulase-positive Staphylococcus (CoPS) strains in veterinary settings in Chile. The aim of this observational study was to identify and characterize CoPS strains from dogs, owners, veterinary professionals and surfaces in a veterinary teaching hospital at Universidad de Chile to determine the presence of methicillin-resistant strains and evaluate the genetic relationship among the strains. Veterinarians (n=24), surfaces (n=10), and healthy dogs (n=40) and their respective owners (n=40) were sampled for CoPS. Isolates were identified by PCR and antimicrobial susceptibility was assessed by the disk diffusion method and MIC. The presence of the mecA gene was evaluated by PCR, and the genetic relationship among the strains was established by PFGE. A total of 45 CoPS strains were obtained, eight from veterinary professionals, three from hospital surfaces, eight from owners and 26 from dogs. Nine of the strains were resistant to methicillin (20%), and all of them carried the mecA gene. A high percentage of the strains was resistant to clindamycin (33.3%). Additionally, the isolated CoPS showed high genetic diversity. This study suggests that veterinarians are in high risk of harboring methicillin-resistant CoPS (25% versus 2.5% from owners) and our results provide evidence that clindamycin could not be an empiric alternative for CoPS in the analyzed hospital. This is the first report of methicillin-resistant CoPS in veterinary settings in Chile, considering humans, pets and surfaces.