In vitro effect of subinhibitory concentrations of ceftazidime and meropenem on the serum sensitivity of Pseudomonas aeruginosa strains

The aim of this study was to determine the effect of subminimal inhibitory concentrations (subMICs) of ceftazidime, meropenem and gentamicin on the in vitro serum sensitivity of Pseudomonas aeruginosa strains isolated from a variety of isolation sites at two medical wards and an intensive care unit in a government university hospital in Croatia. A total of 20 serum-resistant P aeruginosa strains isolated from different clinical specimens were selected. Bacteria were exposed to 1/2, 1/4, 1/8, 1/16, and 1/32 x MIC of each antibiotic tested. Sensitivity of P. aeruginosa strains to bactericidal activity of normal human serum before and after bacterial exposure to subMICs was determined. Significant difference in serum sensitivity of the strains was observed after the bacteria were exposed to subMICs of ceftazidime and meropenem (p < 0.01), while the exposure to subMICs of gentamicin did not affect significantly the resistance of tested strains to the serum bactericidal activity. Comparing the number of serum-resistant strains before and after exposure to subMICs of antibiotics, statistically significant differences were determined (p < 0.01) after exposure of the strains to 1/2, 1/4, 1/8 and 1/16 x MIC of meropenem, and after exposure to 1/2, 1/4 and 1/8 x MIC of ceftazidime. SubMICs of ceftazidime and meropenem affected not only the resistance to serum bactericidal activity of bacteria, but also their morphology. The alterations in bacterial morphology caused by subMICs of ceftazidime and meropenem could be connected with consecutive bacterial serum sensitivity

Utječe li anestezijska tehnika na arterijski tlak i regionalnu moždanu perfuziju tijekom artroskopije ramena u sjedećem položaju?

This study aimed to investigate the impact of posture and anesthesia techniques on blood pressure changes, heart rate and regional cerebral oxygen saturation during shoulder arthroscopy in the beach chair position (BCP). Sixty patients were included in this prospective cohort study: 30 patients mechanically ventilated and subjected to general anesthesia (GA) and 30 patients subjected to interscalene block (ISB) without mechanical ventilation. Noninvasive blood pressure, heart rate (HR), peripheral blood oxygen saturation and regional oxygen saturation of the brain were measured in twelve predefined points during perioperative period. The GA group patients had significantly lower mean arterial pressure and heart rate values compared to patients in ISB group during BCP (p<0.001). There was a significant difference in regional cerebral saturation between the groups measured only in points of induction and emergence from anesthesia in favor of GA group when receiving 100% oxygen (p<0.001). Changes in the mean arterial pressure and regional cerebral oxygen saturation for both brain hemispheres correlated only at the 10th minute after setting up BCP in GA patients (right, p=0.004 and left, p=0.003). This correlation did not exist in the ISB group patients at any of the points measured. Cerebral desaturation events recorded in both groups were not statistically significantly different. Results of this study demonstrated that GA preserved regional cerebral oxygenation in a safe range during BCP despite changes in the arterial blood pressure and heart rate in comparison to ISB.Cilj ovoga istraživanja je bio ispitati povezanost postavljanja bolesnika u sjedeći položaj (engl. beach chair position, BCP) i vrste anestezijske tehnike s posljedičnim promjenama arterijskog tlaka i srčanih otkucaja, kao i njihovog utjecaja na regionalnu moždanu perfuziju tijekom artroskopije ramena. U studiju je bilo uključeno 60 bolesnika: prvu skupinu činilo je 30 bolesnika kod kojih je operacijski zahvat izveden u općoj anesteziji (OA) koji su bili mehanički ventilirani, a drugu skupinu 30 bolesnika kod kojih je operacijski zahvat izveden uz interskalenski blok (ISB) i spontano disanje. U 12 prethodno definiranih točaka tijekom perioperacijskog razdoblja mjerio se neinvazivno arterijski tlak, srčani otkucaji, periferna zasićenost kisikom i regionalna moždana zasićenost kisikom. Bolesnici u skupini OA imali su značajno niže vrijednosti srednjeg arterijskog tlaka i srčanih otkucaja u odnosu na bolesnike u skupini ISB tijekom BCP (p<0,001). Promjene srednjeg arterijskog tlaka i regionalne moždane zasićenosti kisikom za obje moždane hemisfere korelirale su samo u 10. minuti nakon postavljanja bolesnika u BCP kod skupine OA (desna p=0,004, lijeva p=0,003). Ova korelacija nije zabilježena kod bolesnika skupine ISB ni u jednoj od mjerenih točaka. Moždani desaturacijski događaji su zabilježeni u objema skupinama, ali nisu bili statistički značajni. Rezultati ovoga istraživanja ukazuju na to da je OA očuvala regionalnu moždanu zasićenost kisikom unutar sigurnog raspona u usporedbi sa skupinom ISB tijekom BCP, unatoč značajnim promjenama arterijskog tlaka i srčanih otkucaja

Evaluation of Antibacterial Activity of Two Different Honeys against Clinical Isolates of β-hemolytic Streptococci Group A

Introduction: The aim of this investigation was to evaluate in vitro antibacterial activity of horse chestnut honey and acacia honey at different concentrations against clinical isolates of the β- hemolytic streptococci group A (BHS-A). Honey’s active compounds have multiple therapeutic effects and it is used as traditional medicine for treatment and prevention of various illnesses. Materials and methods: The antimicrobial effects of two honeys were tested on forty-four strains of BHS-A, isolated from the throat by a modified disk diffusion method. A bacterial suspension of BHSA strains was plated onto Müller-Hinton agar with 5% defibrinated horse blood. Using a sterile 8 mm diameter cork borer, wells were cut in the agar and into each was introduced 100µL of the different concentrations of the honey solution (25 %v/v, 50 %v/v, 75% v/v and 100%v/v). A disk of penicillin was added as the positive control. The plates were incubated aerobically for18-24 hours at 36 (± 1)°C and zones of inhibition were measured. Results: The average diameter of the inhibition zones of acacia honey (100 %v/v) was 12.48 mm ± 1.73 mm, for acacia honey (75 %v/v) it was 11.06 mm±1.24 mm and for horse chestnut honey (100 %v/v) it was 11.08 mm ± 1.02 mm. The positive control showed the average diameter of 30.45 mm ± 3.21 mm. Statistical significance (p < 0.05) was observed comparing the zone diameters of the acacia honey (100%) and antibiotic penicillin, and between the horse chestnut honey (100%) and antibiotic penicillin. Conclusion: Acacia and horse chestnut honeys exhibit limited but effective antibacterial activity upon clinical isolates of BHS-A. (Kotris I, Talapko J, Drenjančević D. Evaluation of Antibacterial Activity of Two Different Honeys against Clinical Isolates of β-hemolytic Streptococci Group A

WHY MONITORING CEREBRAL DESATURATION EVENTS DURING SURGERY IN THE BEACH CHAIR POSITION?

Moždani oksimetri se koriste u novije vrijeme za nadzor nad regionalnom moždanom oksigenacijom tijekom kirurških zahvata kod kojih se očekuje hemodinamska nestabilnost bolesnika. Jedan od takvih zahvata je operacija ramena u sjedećem položaju, koji se u inozemnoj literaturi naziva “the beach chair position” (engl. BCP). Hipotenzija koja se javlja nakon pozicioniranja bolesnika u sjedeći položaj dovodi do pada perfuzijskog tlaka u mozgu što bi moglo predisponirati potencijalni cerebrovaskularni incident. Cerebralni desaturacijski događaji (engl. cerebral desaturation events, CDE’s) predstavljaju pad vrijednosti zasićenosti kisika u mozgu za 20 % u odnosu na bazalnu vrijednost mjerenu s moždanim oksimetrom INVOS (engl. In Vivo Optical Spectroscopy, INVOS 5100; Somanetics Corp., Troy, Michigan, USA). Zbog tih potencijalnih desaturacijskih događaja koji bi mogli biti štetni za neurološku funkciju istraživači i kliničari stalno nastoje pronaći odgovarajuće metode za nadzor nad moždanom perfuzijom kao i vezu između hipotenzije, smanjene perfuzije mozga, smanjene zasićenosti mozga kisikom i neuroloških incidenata kod bolesnika tijekom artroskopije ramena u sjedećem položaju.Regional cerebral oximeters are used more recently to monitor regional cerebral oxygenation during surgical procedures in which patients are expected to be hemodynamically unstable. Such procedures are cardiac surgery, abdominal surgery that requires anti-Trendelenburg’s position, thoracic surgery with one-lung ventilation, posterior fossa neurosurgery, carotid endarterectomy, and shoulder surgery, performed in the beach chair position (BCP). Patient positioning for particular surgical procedures is extremely important for surgical fi eld visualization, but implies various physiological regulation mechanisms for adaptation to new positions. During patient positioning from supine to other positions, such as BCP, gravity infl uences distribution of the circulating blood volume to the abdomen and extremities. Anesthetized patients have an altered sympathetic response to position changes, which leads to hypotension, particularly during patient positioning from supine to sitting position. Systemic hypotension that occurs after positioning the patient to BCP is followed by decline in the cerebral perfusion pressure, which can lead to potential cerebrovascular incident. There are several case reports describing visual loss and ophthalmoplegia, postoperative cerebral ischemia with persistent vegetative state or brain death following these surgical procedures in BCP. Therefore, BCP is a major challenge for the anesthesiologist and for arterial pressure regulation during the surgery due to hypotension. Some investigators found that cerebral blood fl ow was lower with hypotension (measuring blood velocity in middle cerebral artery with transcranial Doppler) in patients during BCP for shoulder arthroscopy. Monitoring cerebral perfusion in patients during shoulder arthroscopy in BCP is suggested by many authors as a measure to improve patient safety due to potentially endangered brain perfusion. The noninvasive method of the brain oxygenation monitoring is based on the theory of light absorption within the infrared spectrum and uses the near-infrared spectroscopy (NIRS) technology. This monitoring method is user friendly, therefore is gaining much popularity as a method for monitoring cerebral oxygenation. Cerebral desaturation events (CDEs) represent a 20% decline in relation to basal cerebral oxygen saturation values measured with INVOS (In Vivo Optical Spectroscopy, INVOS 5100; Somanetics Corp., Troy, Michigan, USA) cerebral oximeter and are often recorded during this position. Meex et al. carried out a prospective observational study in volunteers and patients in the lateral decubitus position and BCP to describe changes in cerebral tissue oxygen saturation due to changes in body position. They found that more than 55% of patients in BCP had CDEs as compared with volunteers without anesthesia. As these potential CDEs could be detrimental for neurologic function, the clinicians are constantly trying to fi nd appropriate methods for monitoring cerebral perfusion and the link between hypotension, decreased brain perfusion, decreased brain oxygen saturation and neurological incidents during shoulder arthroscopy in BCP. They are also trying to correlate CDEs with possible neurocognitive changes in patients after these surgical procedures, which has not been confi rmed so far. Salazar et al. found that 18% of patients included in their study had the intraoperative incidence of CDEs during BCP but did not fi nd statistically signifi cant preoperative versus postoperative neurocognitive test scores. They concluded that the transient intraoperative CDEs were not associated with postoperative cognitive dysfunction. Patient safety is strongly ssociated with technical and clinical monitoring capabilities during any surgical procedure; therefore, using all available techniques for supervision of the patient’s vital functions is necessary to minimize the occurrence of potential adverse events

The effect of subminimal inhibitory concentrations of antibiotics on the adherence ability of Pseudomonas aeruginosa to epithelial cells in vitro

Background and purpose: The aim of this study was to examine the influence of subminimal inhibitory concentrations (subMICs) of ceftazidime, ciprofloxacin and gentamicin on the adherence ability and morphology of wild-type Pseudomonas aeruginosa strains to the Buffalo green monkey kidney cell line, using indirect immunofluorescence staining. Materials and methods: Bacterial adherence changes were tested before and after exposure to 1/2, 1/4, 1/8, 1/16 and 1/32 MIC of antibiotics. Results: A statistical difference in the number of attached bacteria after exposure to all subMICs of ceftazidime and ciprofloxacin was observed (p&lt;0.05), even after only 1/2 MIC of gentamicin. Conclusion: The results of this study have shown that antibiotics in much lower concentrations than those necessary for inhibition of bacterial multiplications could damage the adherence of Pseudomonas aeruginosa to the epithelial cell line

The effect of subminimal inhibitory concentrations of antibiotics on the adherence ability of Pseudomonas aeruginosa to epithelial cells in vitro

Background and purpose: The aim of this study was to examine the influence of subminimal inhibitory concentrations (subMICs) of ceftazidime, ciprofloxacin and gentamicin on the adherence ability and morphology of wild-type Pseudomonas aeruginosa strains to the Buffalo green monkey kidney cell line, using indirect immunofluorescence staining. Materials and methods: Bacterial adherence changes were tested before and after exposure to 1/2, 1/4, 1/8, 1/16 and 1/32 MIC of antibiotics. Results: A statistical difference in the number of attached bacteria after exposure to all subMICs of ceftazidime and ciprofloxacin was observed (p&lt;0.05), even after only 1/2 MIC of gentamicin. Conclusion: The results of this study have shown that antibiotics in much lower concentrations than those necessary for inhibition of bacterial multiplications could damage the adherence of Pseudomonas aeruginosa to the epithelial cell line

Identification of microorganisms on mobile phones of intensive care unit health care workers and medical students in the tertiary hospital

Aim To identify and investigate a difference between microorganisms present on intensive care unit (ICU) health care workers’ (HCW, doctors, nurses or medical technicians) and medical students’ mobile phones as well as to investigate a difference between the frequency and the way of cleaning mobile phones. Methods Fifty swabs were collected from HCWs who work in the ICU (University Hospital Centre Osijek) and 60 swabs from medical students (School of Medicine, University of Osijek). Microorganisms were identified according to standard microbiological methods and biochemical tests to the genus/species level. Results Out of 110 processed mobile phones, mobile phones microorganisms were not detected on 25 (22.7%), 15 (25%) students’ and 10 (20%) HCW’s mobile phones. No statistically significant difference was found between the number of isolated bacteria between the HCW’ and students’ mobile phones (p>0.05). Statistically significant difference was found between both HCW and students and frequency of cleaning their mobile phones (p<0.001). A significant difference was also obtained with the way of cleaning mobile phones between HCWs and students (p <0.001). Conclusion The most common isolated microorganisms in both groups were coagulase-negative staphylococci (CoNS) and Staphylococcus aureus. Most HCWs cleaned their mobile phones at least once a week, 35 (52.0%), and most medical students several times per year, 20 (33.3%). HCW clean their mobile phones with alcohol disinfectant in 26 (40.0%) and medical students with dry cloth in 20 (33.3%) cases

Arterial pressure and heart rate changes in patients during “beach chair position” for shoulder surgery: comparison of the regional and general anesthesia techniques

Background and Purpose: Patients scheduled to shoulder surgery are placed in a sitting position called “the beach chair position” during the operation. This type of surgery can be performed with two anesthetic techniques: general anesthesia or regional anesthesia (interscalene block). This patient positioning is characterized by changes in heart rate and systemic blood pressure. The aim of this study is to show whether the type of anesthetic technique influence the changes in systemic pressure and heart rate in this particular patient position. Materials and methods: Retrospective clinical study with reviewed anesthetic charts and medical documentation of the patients scheduled for elective shoulder surgery. Point measurements of systolic and diastolic blood pressure and heart rate were: before surgery, after the positioning of the anesthetized patient, at the end of the operation (lodging of the patient) and then the lowest recorded pressure and heart rate during surgery. Results: The study included 66 patients in the sitting position for shoulder surgery. Positioning the patients in the beach chair position for shoulder surgery in a population of patients undergoing general anesthesia in relation to the population of patients treated under regional anesthesia, had a significant effect on the decline in systolic blood pressure (p<0.001) and dyastolic blood pressure (p=0.008). Conclusion: Regional anesthesia has proven again to be the superior technique over general anesthesia, including cardiovascular stability in patients subjected to shoulder surgery in the beach chair position

The effect of subminimal inhibitory concentrations of antibiotics on the adherence ability of Pseudomonas aeruginosa to epithelial cells in vitro

Background and purpose: The aim of this study was to examine the influence of subminimal inhibitory concentrations (subMICs) of ceftazidime, ciprofloxacin and gentamicin on the adherence ability and morphology of wild-type Pseudomonas aeruginosa strains to the Buffalo green monkey kidney cell line, using indirect immunofluorescence staining. Materials and methods: Bacterial adherence changes were tested before and after exposure to 1/2, 1/4, 1/8, 1/16 and 1/32 MIC of antibiotics. Results: A statistical difference in the number of attached bacteria after exposure to all subMICs of ceftazidime and ciprofloxacin was observed (p Conclusion: The results of this study have shown that antibiotics in much lower concentrations than those necessary for inhibition of bacterial multiplications could damage the adherence of Pseudomonas aeruginosa to the epithelial cell line.</p

Multiresistant isolates from sterile material of patients treated in the Pediatrics and Surgery Departments of the University Hospital Osijek in the period 2008–2012

Ovim istraživanjem ispitana je učestalost pojavnosti rezistentnih Gram pozitivnih i Gram negativnih bakterija izoliranih iz primarno sterilnih kliničkih uzoraka bolesnika liječenih na odjelima s različitom bolesničkom populacijom, u Klinici za pedijatriju i Klinici za kirurgiju KBC-a Osijek u razdoblju od 2008. godine do 2012. godine. U promatranom razdoblju u Klinici za pedijatriju i Klinici za kirurgiju KBC-a Osijek rezistentne bakterije izolirane su iz 62 klinička uzorka. U Klinici za pedijatriju bilo je 32 izolata (51,61%) rezistentnih bakterija, a u Klinici za kirurgiju 30 izolata. Najviše je bilo izolata Klebsiella pneumoniae ESBL 41,93% (26/62 izolata), zatim Pseudomonas aeruginosa 27,41% izolata (17/62), meticilin rezistentni Staphylococcus aureus – MRSA 20,96% izolata (13/62) i Acinetobacter baumannii 9,67% izolata (6/62). U Klinici za pedijatriju zabilježena je veća učestalost Gram negativnih rezistentnih izolata za razliku od Klinike za kirurgiju gdje je najčešće izoliran MRSA (12/30). Najčešće izolirana rezistentna bakterija u Klinici za pedijatriju bila je K. pneumoniae ESBL 71,87% (23/32), a zabilježen je samo jedan izolat MRSA. A. baumannii izoliran je samo iz kliničkih uzoraka bolesnika liječenih u Klinici za kirurgiju, a i P. aeruginosa je bio nešto češće izoliran na kirurškim odjelima nego u Klinici za pedijatriju (10 odnosno 7 izolata). Utvrdili smo da je u razdoblju od 2008. do 2012. godine došlo do pada pojavnosti multirezistentnih izolata u Klinici za pedijatriju i Klinici za kirurgiju KBC Osijek i da je najviše rezistentnih izolata zabilježeno u prve dvije godine promatranog razdoblja. Iako izolati P. aeruginosa nisu bili rezistentni na cefalosporine 3. i 4. generacije, zabrinjava visok postotak rezistencije izolata na karbapeneme (58,81% na imipenem i 35,29% na meropenem).The study analyzed the incidence of resistant Gram-positive and Gram-negative bacteria isolated from sterile clinical specimens of patients treated at wards with different hospital population, the Department of Pediatrics and Department of Surgery of the University Hospital Osijek in the period from 2008 to 2012. During the study period resistant bacteria were isolated from 62 clinical samples collected from Pediatrics and Surgery Departments of the University Hospital Osijek. There were 32 isolates (51.61%) of resistant bacteria collected in the Pediatrics Department, and a total of 30 isolates in the Surgery Department. The majority of isolates were isolates of Klebsiella pneumoniae ESBL 41.93% (26/62), followed by Pseudomonas aeruginosa 27.41% (17 / 62), Staphylococcus aureus – MRSA 20.96% (13/62) and Acinetobacter baumannii 9.67% (6/62). Asignificantly higher incidence of Gram-negative resistant isolates was recorded in the Pediatrics Department as opposed to Surgery Department where the most frequent isolate was MRSA (12/30). The most commonly isolated resistant bacteria in the Pediatrics Department were K. pneumoniae ESBL 71.87% (23/32), and only one isolate of MRSA was recorded. A. baumannii was isolated only from clinical specimens of patients treated in the Surgery Department, and P. aeruginosa was also more frequently isolated in the Surgery Department than Pediatrics Department (10 and 7 isolates, respectively). Our study established that in the period from 2008 to 2012 there was a decline in the incidence of multiresistant isolates in the Pediatrics and Surgery Departments of the University Hospital Osijek and that the largest number of resistant isolates was recorded in the first two years of the study period. Although P. aeruginosa isolates were not resistant to the 3rd and 4th generation of cephalosporins, special attention should be given to a high percentage of carbapenem resistance (58.81% to imipenem and 35.29% to meropenem)