Estimation of the contribution to intraoperative pathogen transmission from bacterial contamination of patient nose, patient groin and axilla, anesthesia practitioners' hands, anesthesia machine, and intravenous lumen

BACKGROUND

Earlier studies showed net cost saving from anesthesia practitioners' use of a bundle of infection prevention products, with feedback on monitored Staphylococcus aureus intraoperative transmission. ESKAPE pathogens also include Enterococcus and gram-negative pathogens: Klebsiella, Acinetobacter, Pseudomonas, and Enterobacter. We evaluated whether bacterial contamination of patient nose, patient groin and axilla, anesthesia practitioners' hands, anesthesia machine, and intravenous lumen all contribute meaningfully to ESKAPE pathogen transmission within anesthesia work areas.

METHODS

The retrospective cohort study used bacterial count data from nine hospitals, 43 months, and 448 ESKAPE pathogen transmission events within anesthesia areas of 86 operating rooms. Transmission was measured within and between pairs of successive surgical cases performed in the same operating room on the same day.

RESULTS

There were 203 transmission events with S. aureus, 72 with Enterococcus, and 173 with gram negatives. ESKAPE pathogens in the nose contributed to transmission for 50% (99% confidence limit ≥45%) of case pairs, on the groin or axilla for 54% (≥49%), on the hands for 53% (≥47%), on the anesthesia machine for 21% (≥17%), and in the intravenous lumen for 24% (≥20%). ESKAPE pathogens in the nose started a transmission pathway for 27% (≥22%) of case pairs, on the groin or axilla for 24% (≥19%), on the hands for 38% (≥33%), on the anesthesia machine for 11% (≥7.6%), and in the intravenous lumen for 8.0% (≥5.3%). All P ≤ 0.0022 compared with 5%.

CONCLUSIONS

To prevent intraoperative ESKAPE pathogen transmission, anesthesia practitioners would need to address all five categories of infection control approaches: nasal antisepsis (e.g., povidone-iodine applied the morning of surgery), skin antisepsis (e.g., chlorhexidine wipes), hand antisepsis with dispensers next to the patient, decontamination of the anesthesia machine before and during anesthetics, and disinfecting caps for needleless connectors, disinfecting port protectors, and disinfecting caps for open female Luer type connectors.

Groin wound management after decannulation of veno-arterial extracorporeal membrane oxygenation in heart transplantation: Role of sartorius muscle flap

BACKGROUND

The management of complex groin wounds following VA-ECMO after heart transplant (HT) is uncertain due to limited experience. Sartorius muscle flaps (SMF) have been used in vascular surgery for groin wound complications. However, their use in HT recipients with perioperative VA-ECMO is unclear. This study aims to describe characteristics and outcomes of HT patients with groin complications after arterial decannulation for femoral VA-ECMO.

METHODS

We retrospectively reviewed HT patients who underwent peri-transplant femoral VA-ECMO at our institution from April 2011 to February 2023. Patients were categorized into two groups based on the presence of cannulation-related wound complications.

RESULTS

Among the 34 patients requiring VA-ECMO peri-transplant, 17 (50%) experienced complications at the cannulation site. Baseline characteristics including duration of VA-ECMO support were comparable in both groups. Patients with complications presented mostly with open wounds (41.1%) after a median duration of 22 days post-transplant. Concurrent groin infections were observed in 52.3% of patients, all caused by gram-negative bacteria. Wound complications were managed with 12 (70.6%) undergoing SMF treatment and 5 (31.2%) receiving conventional therapy. Four SMF recipients had preemptive procedures for wound dehiscence, while eight underwent SMF for groin infections. Among the SMF group, 11 patients had favorable outcomes without recurrent complications, except for one patient who developed a groin infection with pseudoaneurysm formation. Conventional therapy with vacuum assisted closure (VAC) and antibiotics were utilized in four patients without infection and one patient with infection. Three patients required additional surgeries with favorable healing of the wound.

CONCLUSION

Complications related to femoral VA-ECMO are common in HT patients, with infection being the most frequent complication. SMFs can be a useful tool to prevent progression of infection and improve local healing.

Umbilicated papules on the bilateral upper and lower extremities

Cryptococcosis is a rare opportunistic infection with morphologically diverse cutaneous presentations. Primary infection typically occurs in the lungs with subsequent hematogenous dissemination to other organ systems, especially in immunocompromised patients. Herein, we report a woman in her 70's who presented with pruritic, umbilicated papulonodules of the bilateral upper and lower extremities present for many weeks. She was diagnosed with disseminated Cryptococcus and subsequently evaluated for potential pulmonary and meningeal disease involvement. She died as a result of multiple medical comorbidities.

Screening cultures for detection of methicillin-resistant Staphylococcus aureus in a population at high risk for MRSA colonisation: identification of optimal combinations of anatomical sites

This retrospective study analysed the diagnostic yield of single-site, two-site, and three-site anatomical surveillance cultures in a population of 4,769 patients at high risk for methicillin-resistant Staphylococcus aureus (MRSA) colonisation. Cultures of seven anatomical sites were used as the gold standard against which to measure the sensitivity of MRSA detection. Detection rates for the seven single-sites, 21 two-site, and 35 three-site combinations are presented. Single-site swabbing only detected 50.5% (nose) of total cases, while three-site surveillance achieved a 92% (groin + nose + throat) sensitivity of detection at best. It is recommended that at least three anatomical sites should be screened for MRSA colonisation in these high-risk patients.

Rapid detection of Methicillin-Resistant Staphylococcus aureus MRSA in nose, groin, and axilla swabs by the BD GeneOhm MRSA achromopeptidase assay and comparison with culture

OBJECTIVES

To compare the BD GeneOhm Methicillin Resistant Staphylococcus aureus (MRSA) Achromopeptidase (ACP) polymerase chain reaction (PCR) assay with the culture method for the detection of MRSA colonization.

METHODS

One hundred and two patients were admitted to the Intensive Care Unit in King Khalid Hospital, Najran, Kingdom of Saudi Arabia from July 2010 to February 2011. Separate swabs from the nose, axilla, and groin of each patient were processed by the culture method (sheep blood agar plate and mannitol salt agar plate) and BD GeneOhm MRSA ACP assay.

RESULTS

Of the 287 samples, 62 (21.6%) were MRSA positive by the PCR assay and 26 (9%) were MRSA positive by the culture method. The PCR method showed 88.4% sensitivity and 98.6% negative predictive value. The number of MRSA-PCR positive groin specimens was nearly the same as nasal specimens. The PCR method gave positive results in 22.5% of patients by nasal specimens, 27.5% of patients by nasal and groin specimens, and 30.4% of patients by nasal, groin, and axilla specimens. The PCR method detected 30.4% of patients as MRSA positive while the culture method detected 19.6% of patients as positive for MRSA.

CONCLUSION

The BD GeneOhm MRSA ACP assay has high sensitivity and NPV and hence is a useful screening method to exclude patients who are not colonized with MRSA.

New acquisition of antibiotic-resistant organisms in skilled nursing facilities

The epidemiology of new acquisition of antibiotic-resistant organisms (AROs) in community-based skilled nursing facilities (SNFs) is not well studied. To define the incidence, persistence of, and time to new colonization with methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), and ceftazidime-resistant (CAZ(r)) and ciprofloxacin-resistant (CIP(r)) Gram-negative bacteria (GNB) in SNFs, SNF residents were enrolled and specimens from the nares, oropharynx, groin, perianal area, and wounds were prospectively cultured monthly. Standard microbiological tests were used to identify MRSA, VRE, and CAZ(r) and CIP(r) GNB. Residents with at least 3 months of follow-up were included in the analysis. Colonized residents were categorized as having either preexisting or new acquisition. The time to colonization for new acquisition of AROs was calculated. Eighty-two residents met the eligibility criteria. New acquisition of AROs was common. For example, of the 59 residents colonized with CIP(r) GNB, 28 (47%) were colonized with CIP(r) GNB at the start of the study (96% persistent and 4% intermittent), and 31 (53%) acquired CIP(r) GNB at the facility (61% persistent). The time to new acquisition was shortest for CIP(r) GNB, at a mean of 75.5 days; the time to new acquisition for MRSA was 126.6 days (P = 0.007 versus CIP(r) GNB), that for CAZ(r) was 176.0 days (P = 0.0001 versus CIP(r) GNB), and that for VRE was 186.0 days (P = 0.0004 versus CIP(r) GNB). Functional status was significantly associated with new acquisition of AROs (odds ratio [OR], 1.24; P = 0.01). New acquisition of AROs, in particular CIP(r) GNB and MRSA, is common in SNFs. CIP(r) GNB are acquired rapidly. Additional longitudinal studies to investigate risk factors for ARO acquisition are required.

The value of multiple surveillance cultures for methicillin-resistant Staphylococcus aureus

BACKGROUND

We evaluated our experience in a low prevalence setting to determine the extent to which multiple swabs increased detection rates and the incremental costs of doing so.

METHODS

Nasal and groin swabs submitted in pairs were cultured onto a single plate (Oxoid MRSA Denim Blue Agar; Oxoid Company, Napean, ON, Canada). We determined whether MRSA was detected when swabs submitted in the preceding 3 days were negative. We explored the costs associated with screening and of each additional colonized patient detected.

RESULTS

In all, 60,049 paired nose and perineal swabs were submitted from 21,599 patients. In all, there were 12,750 duplicate, 1437 triplicate, and 112 instances when >4 swabs were processed within 3 days. The first culture was positive in 106 of 12,750 (0.83%%), 42 of 12,750 (0.33%) on the second when the first was negative, 7 of 1642 (0.43%) on the third or subsequent swab pair when the preceding 2 were negative.

CONCLUSION

Overall, the sensitivity of the first of multiple cultures of a set was 74.3%. Had the 14,392 multiple samples not been submitted, 49 colonized patients would not have been identified. Additional laboratory costs associated with multiple samples equaled $2088 per patient identified.

Methicillin-resistant Staphylococcus aureus (MRSA) detection: comparison of two molecular methods (IDI-MRSA PCR assay and GenoType MRSA Direct PCR assay) with three selective MRSA agars (MRSA ID, MRSASelect, and CHROMagar MRSA) for use with infection-control swabs

Methicillin-resistant Staphylococcus aureus (MRSA) is an increasing problem. Rapid detection of MRSA-colonized patients has the potential to limit spread of the organism. We evaluated the sensitivities and specificities of MRSA detection by two molecular methods (IDI-MRSA PCR assay and GenoType MRSA Direct PCR assay) and three selective MRSA agars (MRSA ID, MRSASelect, and CHROMagar MRSA), using 205 (101 nasal, 52 groin, and 52 axillary samples) samples from consecutive known MRSA-infected and/or -colonized patients. All detection methods had higher MRSA detection rates for nasal swabs than for axillary and groin swabs. Detection of MRSA by IDI-MRSA was the most sensitive method, independent of the site (94% for nasal samples, 80% for nonnasal samples, and 90% overall). The sensitivities of the GenoType MRSA Direct assay and the MRSA ID, MRSASelect, and CHROMagar MRSA agars with nasal swabs were 70%, 72%, 68%, and 75%, respectively. All detection methods had high specificities (95 to 99%), independent of the swab site. Extended incubation for a further 24 h with selective MRSA agars increased the detection of MRSA, with a corresponding decline in specificity secondary to a significant increase in false-positive results. There was a noticeable difference in test performance of the GenoType MRSA Direct assay in detection of MRSA (28/38 samples [74%]) compared with detection of nonmultiresistant MRSA (17/31 samples [55%]) (susceptible to two or more non-beta-lactam antibiotics). This was not observed with selective MRSA agar plates or IDI-MRSA. Although it is more expensive, in addition to rapid turnaround times of 2 to 4 h, IDI-MRSA offers greater detection of MRSA colonization, independent of the swab site, than do conventional selective agars and GenoType MRSA Direct.

Heterosexual transmission of community-associated methicillin-resistant Staphylococcus aureus

Heterosexual transmission of community-associated methicillin-resistant Staphylococcus aureus has not been documented. As part of a survey conducted in northern Manhattan, we encountered 3 households in which heterosexual transmission was responsible for new community-associated methicillin-resistant S. aureus infection. The vaginal and inguinal isolates obtained from the sexual partners were USA 300. This report documents an important and previously unrecognized means of community-associated methicillin-resistant S. aureus colonization and transmission for these potentially invasive strains.

Inguinal lymphadenitis caused by mycobacterium haemophilum in an immunocompetent child

Infections caused by Mycobacterium haemophilum in immunocompetent patients are unusual. M. haemophilum have been associated with cervicofacial lymphadenitis in children, but inguinal infections have not yet been described. We present a case of an inguinal lymphadenitis caused by M. haemophilum in an immunocompetent girl.

Concurrent analysis of nose and groin swab specimens by the IDI-MRSA PCR assay is comparable to analysis by individual-specimen PCR and routine culture assays for detection of colonization by methicillin-resistant Staphylococcus aureus

The IDI-MRSA assay (Infectio Diagnostic, Inc., Sainte-Foy, Quebec, Canada) with the Smart Cycler II rapid DNA amplification system (Cepheid, Sunnyvale, CA) appears to be sensitive and specific for the rapid detection of nasal colonization by methicillin-resistant Staphylococcus aureus (MRSA). We assessed the sensitivity and specificity of this assay under conditions in which both the nose and cutaneous groin specimens were analyzed together and compared the accuracy of this PCR approach to that when these specimens were tested separately and by culture assays in an inpatient population with known high rates (12 to 15%) of MRSA colonization. Of 211 patients screened, 192 had results assessable by all three methods (agar-broth culture, separate nose and groin IDI-MRSA assay, and combined nose-groin IDI-MRSA assay), with MRSA carriage noted in 31/192 (16.1%), 41/192 (21.4%), and 36/192 (18.8%) patients by each method, respectively. Compared to agar culture results, the sensitivity and specificity of the combined nose-groin IDI-MRSA assay were 88.0% and 91.6%, respectively, whereas when each specimen was processed separately, the sensitivities were 90.0% (nose) and 83.3% (groin) and the specificities were 91.7% (nose) and 90.2% (groin). IDI-MRSA assay of a combined nose-groin specimen appears to have an accuracy similar to that of the current recommended PCR protocol, providing results in a clinically useful time frame, and may represent a more cost-effective approach to using this assay for screening for MRSA colonization.

Multiple neonatal staphylococcal cold abscesses of the large folds

BACKGROUND

We describe three neonates who presented around the tenth day of life with multiple bilateral fluctuating cold abscesses situated in the lymph node areas, with secondary fistulation but without associated fever or general symptoms.

RESULTS

In all cases, Staphylococcus aureus was found in the abscesses and the umbilicus with similar antibiograms. The evolution was good and the children remained in good health afterwards.

CONCLUSION

Disseminated neonatal staphylococcal infections with a benign evolution are not commonly described in the medical literature. Clinically, cold inflammatory abscesses of the large folds associated with omphalitis may correspond to either transient bacteriemia well controlled in an immunocompetent host or more likely a local contamination process.

Carriage of multiple subtypes of methicillin-resistant Staphylococcus aureus by intensive care unit patients

OBJECTIVE

To determine how consistently patients are colonized with methicillin-resistant Staphylococcus aureus (MRSA) at various sites and how many subtypes can be carried simultaneously by a single patient.

SETTING

A 28-bed Intensive care unit in a tertiary-care referral hospital.

METHODS

A total of 1,181 patients were screened by culture of swab specimens obtained from the nose, throat, groin, and axilla on admission to the intensive care unit (ICU), twice weekly during their ICU stay, and at discharge.

RESULTS

MRSA was isolated at least once from 224 patients. Of these isolates, 359 were selected from 32 patients to be subtyped using pulsed-field gel electrophoresis. The rate of compliance with collection of swab specimens was 79.9%. The combination of sites colonized varied frequently over time for many patients. Of patients who had swab specimens obtained twice in 1 day, 8.7% had discordant results from the 2 swab sets. No patient had a clinical isolate that was not of an identical subtype to an isolate from an anatomical site that was sampled for screening. Half the patients carried multiple subtypes during their stay, with up to 4 subtypes per patient.

CONCLUSIONS

The findings of this study may indicate that these patients have been colonized with MRSA on more than one occasion, possibly because of multiple breaches in infection control procedure. In MRSA-colonized patients, anatomical sites were intermittently colonized and carriage of multiple subtypes was common. These findings indicate that MRSA carriage is not a fixed state but may vary over time.

Necrotizing fasciitis in a female diabetic patient: a case report

Necrotizing fasciitis is a rare, often fatal, soft tissue infection involving any of the layers of soft tissue. Although rare, cases continue to be reported among patients with impariments of the immune system, such as in diabetics. We present the case of a 53-year-old obese, female, diabetic patient who presented to the Emergency Department at United Hospital Center in Clarksburg with necrotizing fasciitis and was subsequently surgically treated.

Evaluation of separate vs pooled swab cultures, different media, broth enrichment and anatomical sites of screening for the detection of methicillin-resistant Staphylococcus aureus from clinical specimens

Early identification of methicillin-resistant Staphylococcus aureus (MRSA) carriers is a major component of an MRSA control programme. The cost and laboratory workload could be markedly reduced by processing multiple swabs from one person in one culture broth (specimen pooling). We evaluated the sensitivity for MRSA detection and the growth rate of pooled swabs compared with individual processing. In total, 1254 swabs from 423 subjects (two to five swabs per subject) were submitted for detection of MRSA. Swabs were suspended in 2-mL volumes of sterile Todd-Hewitt Broth and divided into two 1-mL aliquots. One aliquot of the suspension was processed as a single specimen, and the other aliquot was mixed (pooled) with other suspensions in which swabs from the same patient were suspended. Forty-four (10%) pooled samples were positive for MRSA. Specimens from seven additional patients that were negative when pooled were positive when processed separately. There was no case where the pooled specimen was positive but the separate specimens were negative. The diagnostic sensitivity of pooled surveillance cultures compared with single cultures, when only subjects colonized by MRSA were considered, was 86% and the false-negative rate was 14%. Eighty percent of the pooled positive cultures were detected by the third day and all were detected by the fourth day. Fifty-four percent of the specimens processed separately were detected by the second day and all were detected by the fourth day. Pooling of specimens decreases the sensitivity of MRSA detection compared with processing each swab separately, particularly in swabs with a low number of colony-forming units. In all subjects whose pooled samples were negative but whose swabs examined separately were positive, the swabs examined separately were negative on primary plates and positive only after culturing in enrichment broth.

Staphylococcal infections in PD: monitoring, screening and prevention

Peritonitis and catheter infections remain a major complication of peritoneal dialysis, accounting for much of the morbidity associated with the technique. The most common source of infection is contamination with predominantly Gram positive skin flora, Staphylococcus (S) epidermidis and S. aureus. The aims of this study were, (a) to determine the incidence of S. aureus and S. epidermidis infections in the unit, (b) to examine whether treatment of S. aureus carriers may reduce the incidence of exit site infection and (c) to examine whether improving patient education may reduce S. epidermidis peritonitis rate.

Comparison of traditional and disposable bed baths in critically ill patients

BACKGROUND

For bedridden patients unable to perform personal hygiene measures because of acute illness or chronic debilitation, the bed bath, with either the traditional basin or, more recently, disposable baths, has long been a measure for improving hygiene and costs.

OBJECTIVE

To compare the traditional basin bed bath with a prepackaged disposable bed bath in terms of 4 outcomes: time and quality of bath, microbial counts on the skin, nurses' satisfaction, and costs.

METHODS

Forty patients in surgical, medical, or cardiothoracic intensive care units received both types of bath on different days. Baths were observed, timed, and scored for quality. Cultures of the peri-umbilicus and groin were obtained before and after each bath. At the end of the study, nurses were interviewed about their preferences.

RESULTS

Neither total quality scores nor microbial counts differed significantly between the 2 bath types. Significantly fewer products (P < .001) and less time were used, cost was lower, and nurses' ratings were significantly better with the disposable bath.

CONCLUSION

The disposable bath is a desirable form of bathing for patients who are unable to bathe themselves in critical care and long-term care settings, and it may even be preferable to the traditional basin bath.

Microbiological aspects of diaper dermatitis

BACKGROUND

The microbiological basis of diaper dermatitis is not clearly elucidated, although a better knowledge of microbial colonisation can be of importance with regard to an adequate treatment.

OBJECTIVE

To investigate the relevance of candida sp. and Staphylococcus aureus colonisation in diaper dermatitis and to determine the correlation between the extent of colonisation and the severity of disease.

METHODS

Growth of candida sp. and S. aureus in the perianal, inguinal and oral regions was determined by positive/negative and semi-quantitative analysis in an open, multi-centre (n = 3) study. Forty-eight children with healthy skin and 28 with diaper dermatitis were analysed. The severity of diaper dermatitis was assessed using a total symptoms score.

RESULTS

Colonisation by candida sp. was significantly more frequent in children with diaper dermatitis as compared to those with healthy skin (perianal 75 vs. 19%; inguinal 50 vs. 10%; oral 68 vs. 25%, p < 0.0003), whereas colonisation by S. aureus at the 3 swab locations was not different (p > 0.34). There was a highly significant, positive correlation between severity of disease and extent of candida sp. colonisation at all swab locations.

CONCLUSIONS

Limited microbial colonisation in diaper dermatitis is of questionable relevance, but extensive colonisation seems to aggravate the symptoms; therefore, we suggest that semi-quantitative evaluation should be preferred to the positive/negative assessment for a differential diagnosis.

Open saphenectomy complications following lower extremity revascularization

A review of saphenectomy site complications following lower extremity revascularization was conducted. Leg incisions used for 133 consecutive infrainguinal bypass procedures were categorized by location. Patient and procedural risk factors were analyzed for risk of wound complications. Procedure, limb and patient outcome were reported via life table analysis. Incisional wound complications followed 32/133 procedures (24%), including 15 groin, eight saphenectomy, five distal and four vein/distal incisions. There were five grade I and three grade II saphenectomy complications. Only weight (body mass index) predicted the likelihood of wound complication (P < 0.05). The 6-month primary patency rate was 79% (mean follow-up 22 months). Four-year assisted primary patency, limb salvage and survival rates were 75, 87 and 57%, respectively. Most bypass-related wound complications (24/32, 75%) involve arterial access incisions. Incisional complications are related to body mass index. Only 6% of GS vein bypass procedures develop saphenectomy site complications. Limiting saphenectomy size may not significantly reduce incisional morbidity following bypass grafting.

A comparison of three staining methods in estimation of structures on the cell wall surface of Acinetobacter junii by using electron microscope

Two strains of Acinetobacter junii isolated from groin and nasal cavity were studied for the presence of structures on the cell wall surface. Three staining methods were used. In the first thin section were contrasted with uranyl acetate and lead citrate. In this method, only electron dense amorphous material could be seen. Using only 1% uranyl acetate, thin fimbriae were observed which in few cases were collected in bundles. Staining with ruthenium red showed bacteria with thick short and long numerous peritrichous structures. Bacteria with structures concentrated near the polar regions were seen as well. From the comparative study of three methods, two of them were found to be useful: methods with ruthenium red and with 1% uranyl acetate.

Colonization pattern of vancomycin-resistant Enterococcus faecium

BACKGROUND

Vancomycin-resistant Enterococcus faecium is increasingly recognized as a serious problem by hospital epidemiologists. Understanding its colonization patterns may help in designing strategies to control its nosocomial spread in the hospital.

METHODS

Twenty patients, selected at random, with vancomycin-resistant E. faecium isolated from cultures of various body sites were studied to determine sites of colonization. For 12 of these patients, cultures of environmental surfaces of their rooms and wards were also obtained.

RESULTS

Eighteen patients (90%) had vancomycin-resistant E. faecium grown in stool cultures. In five patients (25%), vancomycin-resistant E. faecium was cultured from other sites: groins (four), popliteal fossae (three), mouth (one), and an open wound site (one). Patients with positive cultures from the groins and popliteal fossae also had growth of vancomycin-resistant E. faecium in cultures of diarrhea soiling those sites. No patients had the organism isolated from their nares. Vancomycin-resistant E. faecium grew in cultures obtained from bedside stand tables, over-bed tables, used linen, and bedside rails.

CONCLUSIONS

In the 20 patients studied, colonization of vancomycin-resistant E. faecium was limited chiefly to the enteric tract. Absence of colonization of such a secluded area with poor antibiotic penetrability as the nares is encouraging. In our study, vancomycin-resistant E. faecium was isolated from various environmental surfaces from the rooms and wards of patients with vancomycin-resistant E. faecium in their stools.

Quantitative skin cultures at potential catheter sites in neonates

OBJECTIVE

To identify and quantify the bacterial and fungal flora present at body sites used for vascular catheterization of infants in a neonatal intensive care unit.

DESIGN

Quantitative skin cultures were obtained from a group of neonatal patients to determine the bacterial flora found on the skin at four sites. Quantitative cultures of the jugular, subclavian, umbilical, and femoral sites were obtained on 50 infants, ranging in age from 2 days to 3 months old.

SETTING

The neonatal intensive care unit of St. Christopher's Hospital for Children, a university-affiliated tertiary care children's hospital.

RESULTS

Colony counts ranged from 0 to 10(6) colony-forming units/10 cm2. Types of organisms found were consistent with other published studies and included coagulase-negative staphylococci, Staphylococcus aureus, yeast, aerobic gram-negative rods, Enterococcus species, Corynebacterium species, and alpha-hemolytic streptococci. There was a significantly higher mean colony count at the combined jugular/femoral sites versus the subclavian site (P < 0.01) and umbilical site (P < 0.05). Mean colony counts did not differ significantly between the jugular and femoral site, or between the subclavian and umbilical site. The umbilical site was more likely to be colonized with aerobic gram-negative rods, Enterococcus species, and yeast, while the subclavian had coagulase-negative staphylococci as the predominant organism. The jugular and femoral sites demonstrated a higher colony count of aerobic gram-negative rods, Enterococcus species and yeast than the other sites. If central venous catheters need to be in place for extended periods of time, placement at a site with lower bacterial densities on the skin may help minimize catheter-associated infections. This study supports the subclavian as the preferred site.

Does the addition of pre-operative skin preparation with povidone-iodine reduce groin sepsis following arterial surgery?

Sixty-four consecutive patients undergoing elective vascular surgery involving exposure of the femoral artery at the groin were randomized to one of two groups. Group A (N = 34) received twice-daily skin preparation with 10% aqueous povidone-iodine for 48 h preoperatively, while group B (N = 30) did not. Both groups were examined on a daily basis following surgery and any discharge from the wound was recorded and sent for bacteriological culture. The groups were well matched for age, sex and the type of vascular graft material used. In group A there were six (18.7%) groin wound infections and in group B there were five (17.2%). In this series of patients the addition of preoperative skin preparation with 10% povidone-iodine to standard peri-operative prophylaxis had no effect on the incidence of postoperative groin wound sepsis.

Candida albicans--saprophyte or pathogen?

Skin scrapings taken from toe spaces of 200 healthy volunteers and from toe webs and groins of 150 pediatric patients were cultured for Candida albicans using the serum germ-tube test. The results showed that Candida albicans can be isolated in about 15% of normal toe spaces and 14% of children with normal groins. Although Candida albicans can be found in various grades of athlete's foot and also in some abnormal groins, we believe that it is not necessarily responsible for these conditions and is often present at these sites only as a saprophyte.

The efficacy of mupirocin ointment and chlorhexidine body scrubs in the eradication of nasal carriage of Staphylococcus aureus among patients undergoing long-term hemodialysis

BACKGROUND

Patients undergoing long-term hemodialysis have a high prevalence of Staphylococcus aureus nasal carriage, which may lead to serious infections. Mupirocin ointment has been used intranasally to eradicate S. aureus carriage in health human volunteers and health care workers. Chlorhexidine, an antiseptic with excellent antistaphylococcal activity, is widely used for handwashing and skin cleansing.

METHODS

Anterior nares cultures were obtained from patients older than 18 years who were undergoing long-term hemodialysis. Patients with S. aureus nasal carriage were enrolled in the study. Axillae and groins were cultured. Patients were given mupirocin ointment intranasally twice per day for 7 days and chlorhexidine body scrubs daily for the first 3 days. Follow-up cultures were obtained from anterior nares, axillae, and groins at 1 day, and 1, 4, 8 and 12 weeks after treatment.

RESULTS

One day after completion of treatment nasal carriage was eradicated in 83% of patients (15/18). After 12 weeks, 69% of patients (11/16) were free of nasal carriage.

CONCLUSIONS

Success rates of eradication were excellent compared with those in other published reports. This simple and effective regimen had no major side effects.

Genetic dissimilarity of commensal strains of Candida spp. carried in different anatomical locations of the same healthy women

Candida spp. carriage and strain relatedness were assessed in 52 healthy women at 17 anatomical locations by using an isolation procedure which assesses carriage intensity and by using a computer-assisted DNA fingerprinting system which computes genetic similarity between strains on the basis of the patterns of Southern blots probed with the moderately repetitive sequence Ca3. Candida spp. were cultured from 73% of the test individuals, most frequently from the oral (56%), vulvovaginal (40%), and anorectal (24%) regions. Half of the test individuals with Candida spp. carried the organism simultaneously in more than one of the three general areas of carriage. Isolates from different body locations of the same individual were either completely unrelated, identical, or highly similar but nonidentical. In 11 cases in which Candida spp. were simultaneously isolated from the oral cavity and vaginal canal, seven pairs of isolates were genetically unrelated and four pairs were similar but nonidentical. In the latter cases, the isolate pairs each appear to have arisen by genetic divergence from a single progenitor. A comparison of the genetic relatedness of isolates from different individuals further uncovered a single strain which was vaginospecific in the Iowa City, Iowa area and reduced genetic diversity among vulvovaginal strains compared with those isolated from other body locations. These results suggest that strains adapt to different anatomical locations and, conversely, that in a healthy individual there is anatomical selection of vaginotropic, anotropic and orotropic strains of Candida spp.

The effect of femoral arteriography on the incidence of groin contamination and postoperative infections

A prospective study is presented on the effects of preoperative femoral arteriography on bacterial contamination and postoperative wound complications from groin incisions. Forty-four femoral reconstructive procedures (88 groin incisions) for aortoiliac disease were performed. Positive cultures occurred in 43.2% of patients and in 30.7% of the 88 incisions. There was no correlation found between the site of arteriography and positive cultures (Spearman correlation coefficient, p greater than .10). No correlation was found between the presence of hematoma due to arteriography and subsequent positive groin culture (Spearman correlation coefficient, p greater than .10). A higher incidence of positive cultures did occur for patients who had a difficult arteriographic procedure (Fisher's exact test, p = .020) or whose reconstructive procedure was greater than four hours (Fischer's exact test, p = .047). Seven patients had postoperative groin wound complications (15.9%), including three lymph leaks (6.8%) and four confirmed or suspected infections (9%). There were no graft infections. No correlation was found between the site of arteriography and the site of wound complication (Spearman correlation coefficient, p greater than .10). Neither positive culture results nor difficult arteriography nor presence of hematoma were accurate predictors of postoperative wound complications. We conclude that transfemoral arteriography does not increase the risk of complications of arterial reconstruction involving a femoral anastomosis.

Proteeae groin skin carriage among nursing home residents--resistance to antiseptics

Proteeae carriage was evaluated in groin skin carriers following vigorous antiseptic application. Three Proteus mirabilis carriers were treated with 60% isopropyl alcohol or 4% chlorhexidine, observed to prevent skin contact, and then recultured; at four and eight hours P mirabilis numbers remained undiminished. Ten Proteeae carriers received a series of nine body baths with soap, chlorhexidine, and 0.75% povidone-iodine plus three cefazolin injections over 16 to 34 days; cumulative treatments failed to clear seven carriers. Within three months, all were again carriers. Proteeae carriers also had affinity for groin carriage of various aerobic gram-negative bacilli (AGNB) including cefazolin-resistant strains. In seven subjects, more than one AGNB species were recovered shortly after applying an antiseptic. Proteeae groin skin carriage appears to reflect a major change in the nature of resident bacteria on intact groin skin.

Proteeae groin skin carriage in ambulatory geriatric outpatients

Aerobic gram-negative bacillus (AGNB) groin skin carriage was prospectively studied in ambulatory geriatric outpatients: 42 from three nursing homes and 44 from private homes. Initially, 12 (28.6%) Proteeae carriers were in the former group and 3 (6.8%) were in the latter (P = 0.01). At one year, 6 of 7 surviving nursing home carriers remained Proteeae carriers while none from private homes remained carriers (P = 0.007). The annual prevalence of Proteeae carriage was 14 (33.3%) in nursing homes and 4 (9.1%) in private homes (P = 0.008); of non-Proteeae AGNB carriage, the annuyal prevalence was 2 (4.8%) and 4 (11.4%), respectively. Nursing home subjects had similar initial health characteristics; however, by one year, 5 of 12 carriers in contrast to 3 of 30 noncarriers were dead of chronic disease (P = 0.03). These nursing homes included persons with chronic diseases that apparently facilitated Proteeae carriage. Urethral catheters, skin ulcers, and recent antibiotics were not factors.

A study of the skin flora of spinal cord injured patients

The skin flora of 11 spinally-injured patients was compared to that of 11 healthy control subjects. The perinea, groins, penile shafts and urethras of the patients were heavily colonized by a range of multi-drug resistant Gram-negative bacilli. Observations on patients from admission for up to 25 days suggest that the Gram-negative bacilli start to colonize the skin 2-3 days after admission. Some species, e.g., Citrobacter diversus and Escherichia coli appear as transient organisms while others such as Enterobacter aerogenes, Serratia marcescens, and Klebsiella pneumoniae seem to become stable skin residents. The relationship of the skin flora to the organisms causing urinary tract infections in these patients was studied.

Antibiotic-resistant group JK bacteria in hospitals

The organisms designated as Center for Disease Control group JK are gram-positive rods that have previously been described as causing serious infection in compromised hosts. Four years of hospital experience with this group of organisms in Clinical Center patients was reviewed. Studies were also undertaken on specific wards to determine frequency of occurrence and distribution patterns. Inguinal cultures taken on two wards showed that 30 to 35% of patients were colonized with group JK and that newly admitted patients may already be colonized at the time of admission. Colonization was shown to persist for weeks and sometimes months. Isolates obtained throughout the hospital were predominantly from cancer patients, particularly in wounds, abscesses, and drainage sites. Most blood isolates were from granulocytopenic patients with hematological malignancies.