Mycobacterium abscessus infection in solid organ transplant recipients: report of three cases and review of the literature.

Mycobacterium abscessus is an ubiquitous organism found in the environment. This rapidly growing mycobacterium infrequently causes disease in humans; however, in immunocompromised hosts, disease can range from localized cutaneous lesions to disseminated infection. The organism is resistant to most antimycobacterial drugs and therapy can be limited by drug interactions. The exact incidence of M. abscessus infection among solid organ transplant (SOT) recipients is unknown; data are only available from previously reported cases in the literature. We describe 3 cases of M. abscessus infection in SOT recipients diagnosed within a 5-month period. One of the cases followed multi-visceral transplantation, the first such case to be reported in the literature. An epidemiological investigation did not reveal significant commonalities among the cases, and pulsed-field gel electrophoresis of genomic DNA of the case isolates confirmed their non-identity. All cases improved with antibiotic therapy, most notably with the new glycylcycline, tigecycline, along with surgical intervention in 2 of the cases. In addition, we review features and characteristics of M. abscessus infections in recipients of SOT reported in the literature from 1992 to 2008 and summarize some selected therapeutic concerns and issues related to treatment.

Multiple intensive care unit outbreak of Acinetobacter calcoaceticus subspecies anitratus respiratory infection and colonization associated with contaminated, reusable ventilator circuits and resuscitation bags.

PURPOSE: Acinetobacter calcoaceticus subspecies anitratus (A. anitratus) can cause nosocomially and community acquired pneumonia. Source identification of the organism is often difficult. An outbreak of respiratory infection and colonization with A. anitratus affecting 93 ventilated patients in all six of a hospital's intensive care units (ICUs) over 10 months is described. PATIENTS AND METHODS: In April 1984, the infection control staff started to review positive culture results from all patients in all ICUs. At this point, information on significant isolates was recorded by patient, site, date, genus and species, and antimicrobial susceptibility. During the month of August 1984, an increased number of A. anitratus isolates from sputum began to be detected. Information was expanded to include the date of hospital admission, ICU admission, intubation, and extubation; the dates and types of all surgical procedures; the results and dates of all prior sputum cultures; and the use of nebulized bronchodilator medications. Monthly numbers of cases were compared for four months prior to the outbreak, during the outbreak, and for seven months after the outbreak. Plasmid DNA from isolates was prepared, electrophoresed, and visualized. Isolates were designated according to the molecular weights of visualized plasmids. RESULTS: Barrier precautions and improved staff handwashing did not diminish the frequency of new cases. When pasteurized, reusable ventilator circuits and resuscitation bags were cultured for the possibility of low-level contamination, 18 percent were positive for A. anitratus. Terminal ethylene oxide sterilization of these devices was associated with prompt control of the outbreak. Plasmid DNA analysis of isolates from patients involved in the outbreak, contaminated devices, and the hands of personnel responsible for device disinfection revealed two predominant plasmid profiles. After outbreak control, isolates with these profiles were found much less frequently in patient specimens. CONCLUSION: Contaminated, reusable ventilator support equipment may be a leading cause for the extent of A. anitratus in the sputum of intubated patients. This problem is potentially correctable by the use of terminal etyhlene oxide sterilization of reusable ventilator circuits and resuscitation bags.

Campylobacter jejuni-associated hemolytic-uremic syndrome in a mother and daughter.

A mother and daughter with Campylobacter jejuni-associated hemolytic-uremic syndrome (HUS) are discussed. The mother was hospitalized with bloody diarrhea and HUS; C jejuni was isolated from her stool. The 2-year-old daughter had been admitted five days prior to her mother with HUS following a three-day prodrome of vomiting and diarrhea. Multiple stool cultures were negative for enteric pathogens; however, cultures were not obtained until the eighth hospital day and after antibiotic therapy. Extensive investigation failed to identify another cause for the diarrheal illness or HUS in our patients. Indirect immunofluorescent antibody titers for C jejuni were 1:32 and 1:16 for the mother and daughter, respectively. An asymptomatic 9-month-old son had C jejuni isolated from his stool and had an immunofluorescent antibody titer of 1:64. Three other family members were asymptomatic, stool-culture negative, and had immunofluorescent antibody titers less than or equal to 1:4. The susceptibility to develop HUS following an enteric antigenic stimulus is illustrated by the patients presented. The need for systematic investigation of all HUS cases for potential susceptibility markers, as well as an exhaustive etiologic search, is emphasized.

Prophylactic antibiotics and the insertion of permanent transvenous cardiac pacemakers.

Prophylactic antibiotics are prescribed frequently for patients requiring permanent transvenous cardiac pacemakers, despite a paucity of data indicating effectiveness. A 10 year retrospective analysis was performed of 298 pacemaker insertion procedures involving 204 patients. On the basis of prestudy criteria relating to timing and dosage of antibiotics, the use of prophylactic antibiotics was judged as adequate or inadequate. There were no postoperative infections in the 108 battery pack replacement procedures despite no or inadequate use of antibiotics in 49 procedures. There were nine infections in the 190 battery pack plus pacing wire procedures for an infection rate of 5 percent. There was no significant difference in infection rate between the group given prophylactic antibiotics and the group given no or inadequate prophylactic antibiotics. Of the 190 battery pack plus pacing wire procedures, no infections occurred in the 50 procedures in which surgical drains were not used (p less than 0.003). In the 140 procedures in which drains were used, there was no correlation between wound infection and absent or inadequate coverage with prophylactic antibiotics. Two severe bacteremic Staphylococcus aureus infections occurred in two patients not given prophylactic antibiotics. The other seven infections were clinically indolent. These results suggest the following: (1) There is no need for prophylactic antibiotics in battery pack replacement procedures; (2) prophylactic antibiotics may decrease the severity of infection in battery pack plus pacing wire procedures; (3) surgical drains should be avoided in battery pack plus pacing wire procedures. A prospective controlled study is necessary to confirm these results.

Plasmid DNA analysis of Staphylococcus epidermidis isolated from blood and colonization cultures in very low birth weight neonates.

We prospectively studied the course of colonization and sepsis with Staphylococcus epidermidis among 29 very low birth weight neonates undergoing prolonged umbilical catheterization. S. epidermidis bacteremia occurred in 7 patients. In 6 bacteremia was preceded by positive colonization cultures. Isolates obtained from nares, base of umbilicus, umbilical catheter entry sites, catheter tips and blood were examined for plasmid DNA profiles. In 4 patients the plasmid profiles of the catheter entry site isolates were identical with those of the blood isolates. In the other 3 bacteremic patients plasmid profiles of the catheter entry site and blood isolates were different. No correlation was observed in the plasmid DNA patterns of isolates obtained from catheter tip cultures as compared to the corresponding blood cultures. The blood isolates from bacteremic patients had different plasmid profiles.

DNA typing and control of methicillin-resistant Staphylococcus aureus at two affiliated hospitals.

OBJECTIVE: To describe control of endemic and outbreak-related methicillin-resistant Staphylococcus aureus (MRSA) at two affiliated hospitals. DESIGN: Prospective surveillance of patients with MRSA. Disposable gloves were used by all staff having direct contact with the affected patient or his immediate environment, and patient isolates were typed by pulsed-field gel electrophoresis (PFGE) of genomic DNA. Surveillance and PFGE typing were used concurrently to identify possible nosocomial outbreaks, confirm or refute cross-infection, and support a need for additional outbreak control interventions. SETTING: A university hospital (Hospital A) and a university-affiliated public hospital (Hospital B). PARTICIPANTS: Patients with MRSA colonization or infection over an 18-month interval (June 1993-November 1994). INTERVENTION: Proper handwashing and gloving practices were reemphasized with staff following confirmation of outbreaks. RESULTS: Hospital A had 60 community-acquired and 48 nosocomial cases of MRSA. Two small outbreaks (affecting a total of seven patients) and two pseudo-outbreaks were identified. Hospital B had 36 community-acquired and 22 nosocomial cases of MRSA. Only one outbreak affecting five patients occurred. All outbreaks ended shortly after staff meetings that emphasized ongoing and extremely careful handwashing and gloving when caring for identified patients. The majority of nosocomial cases at both hospitals were not related epidemiologically or had isolates with unique PFGE types. Pseudo-outbreaks were confirmed by demonstrating that isolates from epidemiologically related cases (by time and clinical service or hospital unit) had different PFGE types. Hospital A cases had 39 different PFGE types, and Hospital B cases had 31 different PFGE types. CONCLUSION: MRSA in hospitals, including outbreaks identified by prospective surveillance and confirmed by PFGE typing, can be controlled by minimal special precautions and interventions. This is possible despite the continuous admission of patients with MRSA from the community. PFGE typing is useful to confirm outbreaks and pseudo-outbreaks, demonstrate differences among epidemiologically unrelated isolates, and substantiate the efficacy of MRSA control programs within hospitals.

Use of an estimation method to derive an appropriate denominator to calculate central venous catheter-associated bloodstream infection rates.

An outbreak investigation was conducted to determine if an increase in bloodstream infections (BSIs) in patients with central venous catheters (CVC) had occurred. Because other methods of obtaining CVC days were not feasible, we used an estimation method based on a random 5% sample of medical records to determine the proportion of days that a CVC was present for each of three patient units. This calculated ratio was used to estimate the total CVC days for each unit. A cohort study was conducted in which the BSI rates before and during needleless device use were compared. This article describes the methods used to calculate this estimated denominator and discusses the need for such a denominator to be used by infection control practitioners when prospective collection of CVC days is not possible.

Control of methicillin-resistant Staphylococcus aureus in a hospital and an intensive care unit.

OBJECTIVE: To describe methicillin-resistant Staphylococcus aureus (MRSA) control in a hospital, including a surgical intensive care unit (SICU) outbreak. DESIGN: Prospective surveillance of newly identified patients with MRSA. Barrier isolation (disposable gloves for direct contact with patient or immediate environment) was used for the routine care of hospitalized MRSA patients as of October 1991. Beginning in 1992, MRSA isolates were typed by restriction endonuclease enzyme analysis of plasmid DNA (REAP) and/or pulsed-field gel electrophoresis of genomic DNA (PFGE). Surveillance information and MRSA typing were used concurrently to identify nosocomial case clustering, confirm cross-infection, and support a need for additional outbreak control interventions. SETTING: University-affiliated public hospital. PARTICIPANTS: Patients with newly identified MRSA colonization or infection from 1991 through 1993 and epidemiologically associated staff providing care to eight SICU patients in an outbreak. INTERVENTIONS: Barrier isolation for affected and unaffected patients in and admitted to the SICU institution when the outbreak was identified and cross-infection confirmed. Anterior nares cultures of staff in contact with outbreak cases for detection of MRSA colonization. RESULTS: Fifty-six hospitalized patients with community-acquired MRSA and 80 patients with nosocomial MRSA colonization or infection were identified during the 3 years. After the introduction of barrier isolation, the annual frequency of new nosocomial MRSA cases decreased and only one outbreak (eight cases in the SICU) caused by type-related isolates occurred. The other 35 nosocomial cases of MRSA during 1992 and 1993 were not epidemiologically related or were caused by isolates with different types. The SICU outbreak ended after instituting barrier isolation for all patients (with and without MRSA) in and admitted to the unit. Six colonized SICU staff were identified. All outbreak cases had identical or related MRSA types by PFGE and REAP. Staff isolates were different from case isolates by typing, and staff were not restricted and not given treatment for colonization. After more than 6 months of follow up, no further outbreaks of MRSA in the SICU or elsewhere in the hospital occurred despite returning to barrier isolation for affected patients only. CONCLUSION: MRSA in hospitals and outbreaks of MRSA in ICUs can be controlled by surveillance and minimal barrier interventions. REAP or PFGE typing of MRSA can be used to support or refute the presence of cross-transmission. Typing also may be helpful when planning and assessing the effectiveness of interventions directed at endemic, as well as outbreak, MRSA control.

Increased bloodstream infection rates in surgical patients associated with variation from recommended use and care following implementation of a needleless device.

OBJECTIVE: To determine if an apparent increase in bloodstream infections (BSIs) in patients with central venous catheters (CVCs) was associated with the implementation of a needleless access device. DESIGN: Retrospective cohort study using a derived CVC-days factor for estimating appropriate denominator data. SETTING: A 350-bed urban, acute, tertiary-care hospital. METHODS: BSI surveillance data were obtained, and high-risk areas for BSIs were determined. A random 5% sample of medical records was used to estimate CVC days, and a cohort study was conducted to compare BSI rates before and during needleless device use. A survey was conducted of nursing needleless-device practices. RESULTS: The surgical intensive-care unit (SICU), the medical intensive-care unit, and the solid organ transplant unit (OTU) were identified as high-risk units. Using existing surveillance BSI data and the estimated CVC days, the catheter-related BSI rates in the high-risk surgical patients were significantly higher during the needleless-device period compared with the preneedleless-device period (SICU, 9.4 vs 5.0/1,000 CVC days; OTU, 13.6 vs 2.2/1,000 CVC days). A survey of the nurses revealed that 60% to 70% were maintaining the needleless devices correctly. CONCLUSION: We observed a significant increase in the BSI rate in two surgical units, SICU and OTU, associated with introduction of a needleless device. This increase occurred shortly after the needleless device was implemented and was associated with nurses' unfamiliarity with the device, and needless-device use and care practices different from the manufacturer's recommendations.

Plasmid DNA fingerprinting of Acinetobacter calcoaceticus subspecies anitratus from intubated and mechanically ventilated patients.

Forty-three intubated and mechanically ventilated patients in five intensive care units (ICUs) of one hospital developed respiratory colonization or infection with Acinetobacter calcoaceticus subspecies anitratus over a 16-month interval. Neither the frequency nor rate of A anitratus isolation exceeded the hospital endemic norms. Single isolates from 34 of the patients were subtyped by plasmid DNA analysis, two biotyping systems and antimicrobial susceptibility to 24 drugs. Plasmid DNA fingerprints were distinct in 18 isolates (they differed from each other and all others), similar in two and identical or similar in ten. The latter group of isolates were recovered from patients in four ICUs. Reproducibility of biotyping was poor. Neither biotyping nor antimicrobial susceptibility were successful in identifying sameness among the group isolates nor differences among other isolates. We conclude that plasmid DNA fingerprinting should be used to assess the possibility of multiple patient transmissions of the same A anitratus strain in the absence of an obvious outbreak.

Evaluation of the acceptability of a needleless vascular-access system by nurses.

BACKGROUND: Needleless intravenous-access devices have been introduced in an effort to reduce needlestick injuries and possible transmission of blood-borne pathogens to health care workers. However, there are no data on the acceptance of these devices by nursing personnel. METHODS: A survey of nursing personnel was taken at Indiana University Medical Center after introduction of a needleless intravenous device to determine their opinion after use of the needleless device. RESULTS: The majority of the nurses (72 of 94, 70%) had a favorable overall opinion of the device. Among those with a favorable opinion, 76% (55/72) responded that reduced risk of needlestick injury was the most important reason. Among those who had a negative opinion about the needleless-device system, 32% (7/22) reported that contamination risk was their major concern. Those who were trained before device use were more likely to properly use and maintain the needleless intravenous-access system. Of 89 respondents, 75.3% (67/89) believed that the initial training was adequate; however, 43% (29/67) thought that additional training after using the device for some time would have been beneficial. CONCLUSIONS: Comprehensive education programs that include training before and after device use are necessary if new needleless intravenous-access systems are to be successfully introduced and accepted by nursing personnel.

Rubella screening and immunization of health care personnel: critical appraisal of a voluntary program.

At our health care center 1161 personnel and students were offered rubella antibody testing. Ninety-two percent were serologically screened or had been previously immunized or previously proven seropositive. Males were more likely to refuse serologic screening than females (p less than 0.01). Sixteen percent of the seroscreened individuals were found seronegative to rubella. Eighty-five percent of seronegative women less than or equal to 24 years old accepted immunization, as compared to 62% of older females and 55% of all males (p less than 0.01). The total cost of the program was over $11,000. Literature and data review failed to support an increased risk of rubella transmission and/or major consequences to pregnant patients in the health care setting as compared to the community. Voluntary rubella immunization is well received by seronegative young women. Programs for immunization of other health care personnel are unlikely to decrease the number of cases of congenital rubella, are costly, and are not well accepted. Education and immunization of all young susceptible women remain the best methods to substantially decrease the incidence of congenital rubella in a cost-effective manner in the near future.

Reproducibility of Staphylococcus epidermidis plasmid profiles.

The plasmid profiles of six isolates of Staphylococcus epidermidis were repetitively evaluated over an 8-month period. Each isolate was subcultured and stored at three different temperatures (-70 degrees C, -20 degrees C, and room temperature) and plasmid DNA was prepared from each subculture at 0, 1, 4, and 8 months by two different methods of plasmid extraction [using mixed alkyltrimethylammonium bromide (ATAB) or Brij 58 and deoxycholate (modified Parisi)]. Plasmid DNA bands were lost from two isolates when subcultures were kept at room temperature. This plasmid loss was confirmed by repetitive extractions and electrophoresis, as well as by restriction endonuclease analysis of the ATAB preparations. Profiles were otherwise highly related to one another, with occasional exceptions being extra or missing plasmid DNA bands of high molecular size. The latter findings were not reproducible. Plasmid DNA extracted by the modified Parisi method was not reliably digested with restriction endonuclease enzymes. We conclude that the plasmid profiles of Staphylococcus epidermidis isolates are highly reproducible as long as isolates are stored at less than or equal to -20 degrees C. Minor discrepancies in the number of plasmid DNA bands of large molecular size may occur. These are resolvable by repetitive testing or restriction endonuclease analysis of ATAB-extracted plasmid DNA preparations.

Typing of sequential bacterial isolates by pulsed-field gel electrophoresis.

We typed 39 sets of multiple bacterial isolates of the same species from patients by pulsed-field gel electrophoresis of genomic DNA (PFGE). Isolates were cultured from different sites or over a 2-week or longer interval. Staphylococcus aureus, Enterococcus faecalis, Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, and Enterobacter cloacae were tested. Excluding E. cloacae, 28 of 32 sets of isolates (87%) demonstrated only identical or highly related PFGE types. Four of the seven sets of E. cloacae showed different types. For species other than E. cloacae, our results suggest that patients are usually colonized and infected with a single strain of these bacterial pathogens. Unlike all of the other tested species, E. cloacae PFGE typing differences suggested the presence of multiple strains causing colonization and infection.

Characterization of DFA-negative, probe-positive Neisseria gonorrhoeae by pulsed field gel electrophoresis.

Eight Neisseria gonorrhoeae isolates, negative by direct fluorescent antibody (DFA) but positive by a DNA probe, were characterized by pulsed field gel electrophoresis and compared to eight DFA-positive, probe-positive isolates. Results indicate that DFA-negative, probe-positive Neisseria gonorrhoeae isolates may be clonal.

Plasmid DNA analysis, biotyping, and antimicrobic susceptibility as subtyping tests for Klebsiella pneumoniae and Klebsiella oxytoca.

We compared plasmid DNA analysis, biotyping by Vitek, and disk diffusion antimicrobic susceptibility as subtyping tests of Klebsiella pneumoniae and Klebsiella oxytoca. The 92 tested isolates were from alternate, culture-positive patients over 6 months. No outbreak or cluster of infections was recognized during this interval. Plasmid DNA was detected in 85% of the isolates. Each isolate except one had a reproducible absence of plasmid DNA or a reproducible plasmid DNA profile on repetitive testing. Restriction endonuclease enzyme analysis of plasmid DNA was necessary to distinguish differences among some isolates that had only large plasmids. Isolates with only large plasmids represented 18% of the collection. Of the 78 isolates with plasmid DNA, all but two were considered different from one another by plasmid DNA analysis. Biotyping and antimicrobic susceptibility testing were not highly reproducible. In addition, biotyping did not demonstrate a sufficient variety of patterns among the isolates for subtyping purposes. We conclude that plasmid DNA analysis is very useful as a subtyping test for isolates of K. pneumoniae and K. oxytoca. Neither biotyping nor antimicrobial susceptibility as performed in our laboratory had sufficient discriminatory power and reproducibility for subtyping these organisms.

Oral ciprofloxacin in refractory gram-negative bacillary infections.

The 13 patients included in this series: had chronic Gram-negative bacillary infections that were refractory to prior antibiotic therapy; were unable or unwilling to receive intravenous antibiotics; and had altered host defenses or environmental factors that contributed to persistent infection. Five patients had chronic polymicrobic Gram-negative osteomyelitis, three had urinary tract infections caused by Pseudomonas aeruginosa, two had Pseudomonas skin infections and three had respiratory tract infections with Gram-negative bacilli. The overall bacteriological cure rate for Gram-negative bacilli was four of five osteomyelitis, all three urinary tract infections, both skin infections and one out of three respiratory infections. Secondary infections occurred in two patients with bone infections, one with prostatitis and one with deep seated cellulitis and myonecrosis. Two patients with end-stage lung disease had emergence of resistant strains during therapy. Ciprofloxacin was well tolerated and effective in most of the ambulatory patients with refractory Gram-negative bacillary infection. It appears to be especially promising for Pseudomonas infections of the bone, urinary tract and soft tissue.

Molecular epidemiology of Candida albicans colonization and fungemia in very low birthweight infants.

OBJECTIVE: This study investigated the relationship between colonization and fungemia. DESIGN: This was a prospective study involving surveillance cultures of the nares, base of umbilicus, point of entry of umbilical catheter and parenteral fluids. Blood cultures were done when sepsis was suspected. All Candida albicans isolates were typed using restriction enzyme analysis of DNA. SETTING: Patients were from the neonatal intensive care unit of a tertiary care hospital. POPULATION STUDIED: Twenty-nine very low birthweight infants. MAIN RESULTS: Eleven babies were colonized with C albicans and five of these babies developed fungemia, including five of seven who were colonized at the point of entry of the umbilical catheter. Three different strains of C albicans caused fungemia. In four of the five patients, initial catheter entry site isolates were identical to the subsequent blood isolates. Occasionally, infants were colonized with more than one strain of C albicans. CONCLUSIONS: Preceding colonization with C albicans and, in particular, colonization at the site of entry of umbilical vascular catheters are risk factors for subsequent development of C albicans fungemia. Fungemic and colonizing isolates are usually identical to one another by DNA typing.