Distribution of non-aureus staphylococci from quarter milk, teat apices, and rectal feces of dairy cows, and their virulence potential.

Non-aureus staphylococci (NAS) are predominantly isolated from bovine milk samples of quarters suffering from subclinical mastitis. They are also abundantly present on dairy cows' teat apices and can be recovered from bovine fecal samples, as recently described. Differences in ecology, epidemiology, effect on udder health, and virulence or protective traits have been reported among the species within this group. The objectives of this study were (1) to describe the species-specific distribution of NAS in 3 bovine-associated habitats, namely quarter milk, teat apices, and rectal feces, and (2) to evaluate the virulence potential of NAS by comparing their distribution in contrasting milk sample strata and the presence of selected virulence genes. A cross-sectional, systematic sampling procedure was followed in 8 dairy herds that participated in the local Dairy Herd Improvement program in Flanders, Belgium. Quarter milk samples (n = 573) were collected from 144 lactating cows in 8 herds. In 5 of the 8 herds, teat apex swabs (n = 192) were taken from 15 lactating cows, before and after milking, and from 18 dry cows. In the same 5 herds, rectal feces were sampled from 80 lactating cows (n = 80), taking into account that a cow could only serve as the source of one type of sample. In addition, milk samples of all clinical mastitis cases were continuously collected during the 1-yr study period from March 2017 to March 2018 in the 8 herds. In total, 1,676 Staphylococcus isolates were phenotypically identified and subjected to MALDI-TOF mass spectrometry. Thirty-three, 98, and 28% of all quarter milk, teat apex, and rectal fecal samples were NAS-positive, respectively, reaffirming the presence of NAS in rectal feces. The overall predominant species in the 3 habitats combined were Staphylococcus haemolyticus, Staphylococcus chromogenes, and Staphylococcus hominis. Four, 16, and 12% of the healthy quarters (quarter milk somatic cell count ≤50,000 cells/mL of milk), quarters with subclinical mastitis (quarter milk somatic cell count >50,000 cells/mL of milk), and quarters with clinical mastitis, respectively, were NAS-positive, suggesting that the potential to cause (mild) clinical mastitis is present among NAS. This was substantiated by comparing the presence of virulence genes of NAS isolates originating from contrasting milk sample strata (healthy quarters and quarters with clinical mastitis).

Endocarditis infecciosa por Leuconostoc species / Infective endocarditis due to leuconostoc species

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Staphylococcus hominis subsp. novobiosepticus, an emerging multidrug-resistant bacterium, as a causative agent of septicaemia in cancer patients.

Staphylococcus hominis subsp. novobiosepticus is a new sub-species of S. hominis, thus dividing S. hominis into subsp. hominis and novobiosepticus. This study was designed to identify subsp. novobiosepticus isolates amongst the S. hominis isolated from blood samples of patients with malignancy and septicaemia and to study their resistance profile. The identification was performed by using three simple tests which differentiated between the two sub-species. It was found that 22.8 per cent of S. hominis isolates belonged to subsp. novobiosepticus.

Whole-genome sequence of Staphylococcus hominis, an opportunistic pathogen.

Staphylococcus hominis is a commensal coagulase-negative species of staphylococci. It has been considered a presumptive and opportunistic pathogen that causes nosocomial infections in humans. Here we present the draft genome sequence of S. hominis ZBW5, a multidrug-resistant strain isolated from a human skin sample, which provides opportunities to understand the mechanism and genetic basis of its pathogenesis.

Taurolidine lock solution in the secondary prevention of central venous catheter-associated bloodstream infection in home parenteral nutrition patients.

BACKGROUND & AIMS: Central venous catheter-associated bloodstream infection (CBSI) is a serious complication in patients on home parenteral nutrition (HPN). The aim was to analyze the impact of taurolidine-citrate lock solution (TLS) on CBSI rate in HPN patients with a high risk of catheter infection. METHODS: This retrospective study compared CBSI rates 12 months before and 12 months after implementation of TLS. In the first period, only standardized strategies were used to reduce the CBSI rate. In the second period, TLS was injected into the catheter at the end of parenteral nutrition. The CBSI rate with a confident interval was calculated as Poisson event rates, and compared by testing for homogeneity of rates. RESULTS: 15 patients were included. During the 24 months, the CBSI rate was 6.58/1000 catheter-days in the first period and 1.09/1000 catheter-days in the second period (p < 0.001). In patients with TLS once a week (n = 8), the CBSI rate decreased from 4.8/1000 catheter-days to 1.37/1000 catheter-days (p = 0.02) and in patients with TLS after each TPN (n = 7), the CBSI rate decreased from 8.61/1000 catheter-days to 0.78/1000 catheter-days (p = 0.001). CONCLUSION: In HPN patients, TLS associated with standardized precautions significantly reduced the CBSI rate.

Diseminación nosocomial de Staphylococcus hominis resistente al linezolid en dos hospitales de Mallorca / Nosocomial spread of linezolid-resistant Staphylococcus hominis intwohospitals in Majorca

Introducción A partir del 2008 se detectaron varios aislados de Staphylococcus hominis (S. hominis) multirresistentes, incluyendo resistencia al linezolid y a la teicoplanina, en pacientes ingresados en dos hospitales de Mallorca. Por ello, se inició un estudio para determinar la epidemiología molecular y el mecanismo de resistencia al linezolid. Métodos El estudio de epidemiología molecular se realizó mediante electroforesis en campo pulsado (ECP), tras digestión con ApaI. Se efectuó amplificación de un fragmento de los genes ARNr 23S (con secuenciación posterior) y cfr. Resultados Desde marzo de 2008 hasta febrero de 2009 se detectaron 15 aislados de S. hominis resistentes al linezolid y a la teicoplanina, procedentes de 14 pacientes. Todos ellos excepto uno habían ingresado en las Unidades de Cuidados Intensivos de alguno de los dos hospitales. La mayoría de los aislados (9) se obtuvieron en hemocultivos. Gran parte de los pacientes infectados (12 de los 15 episodios infecciosos, el 80,0%) recibieron pautas de linezolid antes de la detección del aislado resistente. La ECP reveló la presencia de un único clon entre los aislados de S. hominis resistentes al linezolid. Se detectó la mutación G2576T en todas las cepas resistentes, mientras que la PCR del gen cfr fue negativa en las mismas. Todos los aislados fueron también resistentes a la penicilina, oxacilina, trimetoprim-sulfametoxazol, ciprofloxacino, levofloxacino y tobramicina; y sensibles a la eritromicina, tetraciclina, gentamicina y daptomicina. La CMI a la vancomicina fue de 4μg/ml en todos ellos. Conclusiones La detección de cepas de estafilococos resistentes al linezolid resalta la necesidad de racionalizar el uso del linezolid y mantener un control activo de dicha resistencia con objeto de preservar la utilidad clínica de este antimicrobiano (AU)

Objective: Since March 2008, several linezolid and teicoplanin-resistant Staphylococcus hominis (S. hominis)isolates have been recovered from patients admitted to the two major hospitals on the island of Majorca, Spain. For this reason, a study was conducted to determine the molecular epidemiology of these isolates and the mechanism of linezolid resistance. Methods: The molecular epidemiology study was performed by pulsed-field gel electrophoresis (PFGE)analysis, after digestion with ApaI. Linezolid resistance mechanisms were evaluated by PCR amplification of a fragment of the domain V of the 23S rRNA gene (followed by sequencing) and cfr gene. Results: From March 2008 to February 2009, 15 linezolid and teicoplan in-resistant S. hominis isolates were recovered from 14 patients. All of them, except one, were hospitalised in the intensive care units of either of the two institutions. Isolates were obtained mainly from blood cultures (9). The majority of infected patients (12 of 15 infectious episodes, 80.0%) had received courses of linezolid prior to detection of the resistant isolate. PFGE analysis revealed the presence of a unique clone among linezolid resistant S. hominisisolates. The G2576T mutation was detected in all the linezolid resistant strains. None of the resistant isolates showed a positive PCR for the cfr gene. All of the isolates were also resistant to penicillin, oxacillin, trimethoprim-sulfamethoxazole, ciprofloxacin, levofloxacin, and tobramicin; whereas all of them were susceptible to erythromycin, tetracycline, gentamicin, and daptomycin. The MIC of vancomycin was4 g/ml for all the strains. Conclusions: The detection of linezolid resistant Staphylococci highlights the need to rationalise the use of linezolid, and maintain an active surveillance of its resistance to preserve the clinical usefulness of this antimicrobial (AU)

Síndrome de Sweet asociado a colitis ulcerosa / Sweet syndrome inapatient with ulcerouscolitis

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Piomiositis, sacroiliitis y espondilodiscitis por Staphylococcus hominis en una mujer sin compromiso inmune / Pyomiositis, Sacroilitis and spondylodiscitis caused by staphilococcus hominis in a immunocompetent woman

Las infecciones osteoarticulares por estafilococos coagulasa negativos son raras en ausencia de factores de riesgo. Presentamos una paciente de 73 años, sin evidencia de compromiso inmune, que desarrolló piomiositis, sacroiliitis izquierda y espondilodiscitis involucrando las dos primeras vértebras dorsales por Staphylococcus hominis. El cuadro clínico infeccioso se desarrolló durante las cinco semanas que siguieron la administración de antiinflamatorios no esteroideos por vía intramuscular a causa de dolor lumbosacro asociado a una hernia discal L4-L5. Esta es la primera descripción conocida de una infección musculoesquelética multifocal por Staphylococcus hominis en una paciente no inmunocomprometida

In abscense of risk factors, osteoarticular infections by coagulase-negative staphylococci are very infrequent. We described the case of a immunocompetent 73-year-old-woman that suffered pyomyositis, left sacroiliitis and spondylodiscitis involving the first and second thoracic vertebrae by Staphylococcus hominis. This multifocal infection occurred five-weeks after intramuscular administration of NSAI for treatment of low back pain associated with a herniated disc L4-L5. This is the first know case of a multifocal muscleskeletal infection by Staphylococcus hominis in a patient immunocompetent