Biofilm formation under food-relevant conditions and sanitizers' tolerance of a Pseudomonas fluorescens group strain

AIMS

The aim of this study was to determine the biofilm-forming ability of a strain belonging to the Pseudomonas fluorescens group isolated from the dairy environment under food-relevant conditions. Moreover, the effects of commercial sanitizers against preformed biofilms were assessed both in terms of viability and structure.

METHODS AND RESULTS

The biofilms were formed on polystyrene, stainless steel (SS), and polytetrafluoroethylene (PTFE) in a wide range of temperatures (4-25°C) and were subjected to the action of 10 different sanitizers. The strain under study showed to be a strong biofilm-former regardless of temperature, particularly on polystyrene. The biofilms were mostly sensitive to chlorine and peracetic acid-based sanitizers. For some sanitizers (e.g. amphoteric), a relationship was observed between the material and the tolerance, while the temperature was not statistically significant. The formation of long-term biofilms on SS was also structurally affected by the temperature, showing microcolonies more irregular in shape and with lower cellularity at 4°C compared to 15°C, where the biofilm was more compact and with a high presence of EPS.

CONCLUSIONS

The strain belonging to the P. fluorescens group was shown to quickly adhere and form mature biofilm at temperatures and on materials relevant to the food sector; however, biofilms formed under different conditions were differently tolerant to disinfectants.

SIGNIFICANCE AND IMPACT OF THE STUDY

Findings from this study could provide a basis for developing targeted sanitation protocols in food plants.

Safety-related properties of staphylococci isolated from food and food environments

AIMS

To test some safety-related properties within 321 staphylococci strains isolated from food and food environments.

METHODS AND RESULTS

The isolates were identified as Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus saprophyticus, Staphylococcus pasteuri, Staphylococcus sciuri, Staphylococcus warneri and Staphylococcus xylosus. Decarboxylase activity was quite common for the various Staphylococcus spp., and tyrosine was the most frequently decarboxylated amino acid. The frequency of antibiotic resistance was highest in Staph. pasteuri and Staph. xylosus. Several of the isolates were tolerant to QAC compounds, and in some cases, QAC tolerance was present in antibiotic-resistant strains. Most of the strains displayed moderate to high adhesion rates to stainless steel and Teflon(®). The strains that readily formed biofilms belonged to the species Staph. aureus, Staph. epidermidis and Staph. pasteuri.

CONCLUSIONS

An high incidence of some safety hazards was found within the staphylococcal strains of food origin tested in this study. In particular, amino acid decarboxylase activity and biofilm-forming ability were common within strains, and antibiotic resistance and tolerance to QAC-based compounds occurred frequently as well. These characteristics are an important safety concern for food industry.

SIGNIFICANCE AND IMPACT OF THE STUDY

This work gives a first picture of safety hazards within staphylococcal species isolated from food environments. The presence of disinfectant-resistant staphylococci is a concern because resistance can be genetically transferred between the various Staphylococcus species. This could lead an increase and spread of resistant enterotoxic staphylococci and/or pathogenic staphylococci.

Laparoscopic resection of colorectal cancer: matched comparison in elderly and younger patients

BACKGROUND

Several studies have addressed the issue of the feasibility of laparoscopic colorectal surgery in elderly patients, usually by choosing an arbitrary cut-off age limit, and retrospectively evaluating patient outcomes. The aim of this study was to assess the effects of age on the outcome of laparoscopic colorectal surgery for cancer in a single department, by comparing younger and older patients, matched by ASA score and type of operation.

METHODS

The perioperative outcome of patients ≥75 years old who underwent laparoscopic colorectal surgery for cancer between June 2005 and January 2009 were compared with findings in younger patients, matched by ASA score and type of operation.

RESULTS

The study included 100 patients, fifty <75 years old (Group A) and fifty ≥75 (Group B) years old. There were 18 right hemicolectomies, 16 left hemicolectomies, 4 anterior resections, 9 low anterior resections, 2 Miles' operations and 1 segmental resection in each group. We observed a significantly higher overall morbidity rate among elderly patients than among younger patients (24 vs. 8%).

CONCLUSIONS

Short-term results after laparoscopic colorectal surgery for cancer in patients ≥75 years old reveal that they have higher postoperative risk compared to their younger counterparts, even when matched by ASA score and type of operation. It suggests that although advanced age, per se, is not a contraindication, it is a risk for patients who undergo laparoscopic colorectal surgery for cancer. This surgery in elderly patients should be performed by experienced surgeons in specialized centers to keep postoperative risk to a minimum.

Laparoscopic colorectal surgery in the elderly

BACKGROUND

The efficacy and safety of laparoscopic colorectal surgery have been demonstrated in several well designed trials in recent years. At the same time the experience in the field of laparoscopy in the elderly has increased. The aim of this study was to evaluate retrospectively the experience of laparoscopic colorectal surgery in patients over 75 years in our unit.

DESIGN

Retrospective study.

SETTING

Surgical Department, San Lorenzo Hospital, Valdagno (VI).

SUBJECTS AND METHODS

All the patients over 75 years, out of a total number of 121 unselected patients, undergoing laparoscopic colectomy or laparoscopic abdomino-perineal resection between June 2002 and May 2005.

MAIN OUTCOME MEASURES

Postoperative mortality, operating time, conversion rate, morbidity, time of discharge from hospital.

RESULTS

Six patients were converted to open surgery. 87 patients over 75 years underwent laparoscopic colorectal surgery. There was no postoperative death, in three cases a reoperation was done, because of postoperative intestinal obstruction in one case (over 75) and for anastomotic fistula in two (one over 75, after low anterior resection). Mean operative time was was 180 minutes (range 150-300).

CONCLUSIONS

Laparoscopic colorectal surgery in elderly patients is a safe group of procedures for benign and malignant lesions of large bowel, resulting in a low rate of complications even if the time of operation is increased compared with open procedures. Postoperative pain and hospital stay, with return to normal life, are decreased compared with open surgery.

Electromagnetic field monitoring and control systems: state-of-the-art and work-in-progress

The development of EMF monitoring and control systems unquestionably represents one of the major innovations in the range of methodologies for evaluating, through measurement, the so-called environmental electromagnetic pollution. The interest recently shown by ARPA and municipal and provincial councils for setting up electromagnetic field monitoring and control systems has created significant developments in the field under examination. This paper attempts to provide a complete overview of the technical possibilities provided by electromagnetic field monitoring and control systems in the environment and their possible applications. Equipment currently available and under development is described, as well as the most significant work-in-progress in this sector. In the near future, several monitoring systems will be proposed and set up by municipalities and provinces, or directly by telecommunications companies. For this reason, it is more than ever necessary that agreement be reached at a national level to define a unified methodological and operating approach to enable monitoring data from different sources to be compared.

[Our experience with the use of Absolok polydioxanone resorbable clips in laparoscopic surgery]

BACKGROUND

The study aims to evaluate the efficacy of resorbable clips in polydioxanone in laparoscopic surgery.

METHODS

The authors report their personal experience regarding the use of Absolok (ABL) resorbable clips in laparoscopic surgery. Out of a total of 745 laparoscopic operations performed from September 1992 to February 1997, 438 included the use of resorbable clips in place of metal clips, both for cystic duct section during cholecystectomy and vascular structures, or to lock continuous sutures. ABL clips were also used for major vessels (e.g. mesenteric artery) during laparoscopic colic resections.

RESULTS

In all cases when they were used, ABL never gave rise to complications, such as biliary outflow or hemorrhage caused by the dislocation of the clips themselves.

CONCLUSIONS

The authors conclude by affirming the value and safety of this type of clip.

Conservative laparoscopy in the treatment of posttraumatic splenic laceration using microfiber hemostatic collagen: three case histories

Three cases of posttraumatic splenic laceration in young patients are reported. In each case, hemostasis of the lesion was obtained by the use of microfiber collagen in emergency laparoscopy. In two cases, complete hemostasis was achieved and the entire organ was saved. In the third case, splenectomy proved necessary after renewed bleeding occurred.

Ileal volvulus on internal hernia following left laparoscopic-assisted hemicolectomy

Described here is a case of constriction of the ileal loop caused by a volvulus forming on an internal hernia through the mesenteric opening in the anastomotic colonic stumps, following left laparoscopic-assisted hemicolectomy. This experience indicates the need for closure of mesenteric gaps with a continuous suture after laparoscopic-assisted left hemicolectomy.

Palliative treatment of carcinoma of the rectum by endoscopic injection of polidocanol

Between January 1987 and December 1988, at the Surgical Department of Chiarenzi Hospital, five patients underwent endoscopic intratumoral injection of polidocanol for palliative treatment of inoperable carcinoma of the rectum. Histological evaluation was performed in all cases. The patients comprised two males and three females aged 78 to 88 years (mean 83.4). One of them refused surgery for recurrent rectal cancer, four consulted us with impending intestinal obstruction; three were inoperable due to local spread of the tumor and poor general condition, the other was in a poor general condition due to massive metastatic hepatic disease. In all the patients, we observed remission of the obstructive symptoms with no major complications; none of them has required a colostomy. The follow-up period has covered a period of two months to two years. The technique of injection is simple, inexpensive and, properly performed, safe. All these advantages make this type of palliative treatment for rectal cancer interesting, even when compared with laser treatment, urological resectoscope or electric snare resection, and electrocoagulation.

Thoracic complications of pancreatitis

Pancreatitis may be associated with thoracic complications, notably chronic massive pleural effusion (CMPE) and, rarely, pseudocysts with mediastinal extension (PME) and enzymatic mediastinitis (EM). Our personal experience with 14 cases of thoracic complications (nine CMPE, two PME associated with pleural effusion, and three EM of 670 patients who underwent surgery; of these, 191 had acute and 479 had chronic pancreatitis) during 16 years (1970-1986) is reported. In the patients with CMPE, the initial symptoms were progressive dyspnea eventually associated with cough and chest pain. In the PME cases, there was dysphagia associated with left subscapular pain and left chest pain. The initial signs in the patients with EM were sudden dyspnea, cyanosis, retrosternal pain, tachycardia, and acute heart failure. A fistula between the pancreatic ductal system and the pleural cavity in seven of the nine patients with CMPE was demonstrated by intraoperative pancreatography and/or cystography. On the contrary, preoperative endoscopic pancreatography demonstrated the sinus tract in only three of the seven. In both cases of PME, computed tomography (CT) provided a correct diagnosis that was confirmed at surgery. In the patients with EM, the diagnosis was suggested by the clinical appearance and was confirmed by the chest roentgenogram and by CT. All patients had operations after varying periods of unsuccessful 2-4-week-long conservative treatment. One patient with infected ascites died postoperatively. There were no thoracic recurrences of pancreatic disease among the other patients at a 10-month-10-year follow-up observation after surgery.

[Preoperative evaluation of the patient candidate for surgical intervention on the chest: methods of study and risk factors]

The authors review the main methods designed to evaluate operability and surgical risk in candidates for chest surgery. They also report on their own experience with 135 cases operated on for thoraco-pulmonary diseases requiring surgery; in these cases, postoperative complications were studied in relation to various respiratory parameters evaluated differentially and as a whole prior to surgery. This study enabled the investigators to establish that patients with CV, FEV1, FEF25-75 and Tiffffeneau Index values below 60% of the respective theoretical reference values run a very substantial risk of postoperative complications, with a post-surgical morbidity rate of more than 60% in such patients. Similar risks are run by patients with VR values below 60% or above 120% of predicted values or with Emphysema Index values above 120% of predicted values. The author's experience with fractional bronchospirometry revealed that, in the high-risk patient sample, a predicted postoperative FEV1 value of only 800 ml/sec is a poorly selective limit.

Leiomyomata of the oesophagus: report of four surgically-treated cases

Four patients with leiomyoma of the upper or middle third of the oesophagus treated by surgical excision are reported. All operations were performed through a right thoracotomy with simple enucleation of the lesion. Two patients were asymptomatic. In one the tumour had a spiral configuration almost completely surrounding the lumen. No complications occurred. Early surgical treatment is advised although the tumour grows slowly.

[Respiratory function after traumatic rupture of the diaphragm]

In eight patients who underwent surgical treatment for diaphragmatic rupture, pulmonary function and differential ventilation of the lungs were evaluated four months-one year after surgery. The results of the study show that diaphragmatic rupture produces only a small reduction in total ventilatory function. Moreover our data indicate that the ventilation estimated to be contributed by the side injured, is decreased in a larger extent in abdominal than in thoracic trauma.

[Our experience in the use of "traction" endoprosthesis as a palliative treatment of cardial carcinoma]

The Authors review the methods of palliative treatment of cardial carcinoma, and particularly report some results obtained through the application of oesophageal endoprostheses (by Celestin and by Haring), following the traction method, in 38 patients. The global mortality amounted to 8 cases (21%). In 12 patients (31%), complications such as stoppage or dislocation of the prosthesis were observed. In two cases the perforation of oesophageal wall occurred, with spontaneous resolution in one of the two patients and serious mediastinitis and exitus in the other. The Authors' present trend is toward the use of push type endoprosthesis, because of the lower mortality reported in literature.

[Surgical therapy of gastric carcinoma in an advanced stage (clinical cases)]

The Authors study the casuistry of the Verona Surgical Clinic concerning the interventions for gastric cancer; they particularly study 35 cases of plurivisceral demolition for neoplasm in advanced phase. After a discussion of the data supplied by the literature; the Authors, as a conclusion, suggest not to consider the overcoming of the gastric barrier in multivisceral sense as a rigid element for the exclusion of these patients from surgery, although they exclude widely demolitive interventions in seriously weakened patients, or in bearers of such spreadings as to involve tremendous operative risks, not rewarded with a satisfactory advantage.

[Traumatic rupture of the diaphragm. Diagnostic problems and surgical therapy]

The Authors show 10 cases of traumatic disruption of diaphragm, subsequent to close or open trauma, all subjected to urgency operation. They discuss the problems concerning diagnosis and surgical tactics, and point out the frequency of visceral and osseous associated lesions and their importance in conditioning prognosis.