Community-acquired multiresistant bacteria - A potential pandemic ?

[Gert van der Hoek]

In this thread information will be gathered about community-acquired multiresistant bacteria.

These mulitresistant bacteria and infections can be found frequently in hospitals .

More and more studies however show the circulation of the multiresistant bacteria outside hospital settings.

For instance:


Metallo-β-Lactamase from Traveler Returning to Canada
See: http://www.flutrackers.com/forum/showthread.php?t=158981


Escherichia coli O25b-ST131: a pandemic, multiresistant, community-associated strain.
See: http://www.flutrackers.com/forum/showthread.php?t=159011


Belgium - Rapid emergence of multiresistant CTX-M-15-producing E. coli isolates
See: http://www.flutrackers.com/forum/showthread.php?t=159013


Antibiotic-resistant E-Coli - incl. ESBL - found in waterbirds in Poland, Sweden, France, Portugal
See: http://www.flutrackers.com/forum/showthread.php?t=154058


Antibiotic resistant bacteria in surface water in an area with a high density of animal farms in the Netherlands
See: http://www.flutrackers.com/forum/showthread.php?t=156393


NDM-1 — A Cause for Worldwide Concern
See: http://www.flutrackers.com/forum/showthread.php?t=156541

NDM-1 is found in E. coli - the most frequent cause of urinary tract infections, which is commonly found in the community. The fact that E. coli is a typical community-acquired bacteria may also accelerate the spread of NDM-1 resistant strains, since the resistance is not limited to the healthcare setting.
Read more



More and more people are silent carriers and spreaders of multiresistant bacteria. Many face hard to cure and life-threatening infections.

A potential pandemic?


The treatment of tuberculosis meets serious problems because of the spread of MDR and XDR anti-biotic resistant bacteria.
Information and news can be found here: http://www.flutrackers.com/forum/forumdisplay.php?f=617
Several new TB vaccins are being developed.

Please also read:

Antibiotic resistance is a universal problem. Like global warming, it requires joint action.
See: http://www.flutrackers.com/forum/showpost.php?p=370632&postcount=1


The bacterial challenge: time to react - At least 25,000 die each year in Europe from multidrug-resistant bacteria
See: http://www.flutrackers.com/forum/showthread.php?t=152080


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[Gert van der Hoek]

Re: Community-acquired multiresistant bacteria - A potential pandemic ?

Zhongguo Dang Dai Er Ke Za Zhi. 2011 Jan;13(1):16-19.

[Nasal carriage of community-acquired methicillin-resistant Staphylococcus aureus in healthy children from Chengdu.]

[Article in Chinese]

Abstract

OBJECTIVE: To evaluate the prevalence of nasal carriage of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) in healthy children from Chengdu.

METHODS: Strains of Staphylococcus aureus were isolated from nasal swabs of healthy children from five kindergartens in Chengdu from September, 2005 to December, 2005 and questionnaires were obtained. Antibiotic susceptibility test was performed with agar disk diffusion and Bauer-Kirby on Mueller-Hinton medium method to determine CA-MRSA. mecA and PVL genes were detected with PCR in all of the CA-MRSA isolates.

RESULTS: A total of 801 children were enrolled. Overall 147 children (18.4%) were carried with Staphylococcus aureus and 9 (1.1%) were carried with CA-MRSA. All CA-MRSA isolates were positive for mecA gene, and 5 CA-MRSA isolates were positive for PVL gene. Of the 9 CA-MRSA isolates, 6 were multiresistant.

CONCLUSIONS: CA-MRSA nasal colonization is present among Chengdu healthy children. The CA-MRSA isolates are multiresistant and parts of CA-MRSA isolates carry PVL gene. The nasal carriage of CA-MRSA in healthy children should be a concerned issue.

http://www.ncbi.nlm.nih.gov/pubmed/21251379

 

[Gert van der Hoek]

Re: Community-acquired multiresistant bacteria - A potential pandemic ?

Med Sci (Paris). 2010 Nov;26(11):943-9.

[Staphylococcus aureus resistance to antibiotics: key points in 2010].

[Article in French]

Abstract

Staphylococcus aureus has a strong adaptive capacity and thus acquired various types of resistance to antistaphylococcal agents. More than 90% of isolates produce a penicillinase.

Oxacillin remains active against these strains, but hospital associated staphylococci and more recently community acquired staphylococci have developed crossed resistance between methicillin (MRSA), oxacillin and other beta-lactams by production of a penicillin binding protein (PBP) with low affinity for beta-lactams, PBP2a.

The gene encoding PBP2a, mecA is carried by a chromosomal element which also contains other resistance genes to heavy metals and other antibiotics thus explaining the multiresistant profile of hospital associated MRSA.

By contrast, community acquired MRSA (CA-MRSA) are only resistant to kanamycin, fusidic acid and tetracycline, in addition to methicillin.

This profile is specific of the European CA-MRSA ST80 clone which also encodes for a very particular virulence factor, the Panton-Valentine leukocidin. Glycopeptides, vancomycin and teicoplanin, are alternatives to oxacillin in case of resistance or intolerance.

Strains with decreased susceptibility to glycopeptides have been reported. Their detection is difficult but necessary because vancomycin MIC creep seems linked to poor outcome in patients.

http://www.ncbi.nlm.nih.gov/pubmed/21106176

 

[Gert van der Hoek]

Re: Community-acquired multiresistant bacteria - A potential pandemic ?

J Infect Dev Ctries. 2009 May 1;3(4):295-9.

Extended spectrum beta-lactamases (ESBL) in Escherichia coli and Klebsiella pneumoniae: trends in the hospital and community settings.


Abstract

BACKGROUND: To assess the prevalence of extended spectrum beta-lactamase (ESBL) producing Escherichia coli and Klebsiella strains in nosocomial and community-acquired infections.

METHODOLOGY: The study was conducted at a centralized microbiology laboratory in the Eastern Province of Saudi Arabia. Laboratory records (January 2004 - December 2005) were assessed. Associated resistance to a panel of antibiotics was determined.

RESULTS: A total of 6,750 Gram-negative organisms were assessed for ESBL-phenotype. ESBL was detected in 6% (409/6,750) of isolates, the majority of which were E. coli (83%). ESBL producers were significantly higher among isolates from in-patients 15.4% (143/927) versus out-patients (4.5%; 266/5,823); p < 0.05.

Old age (older than 60 years) represented a significant risk for having an ESBL-producing pathogen. Urine was the major source of ESBL isolates in in-patients (46.1%) and out-patients (74.4%).

The proportion of urinary E. coli isolates which were ESBL producers was significantly higher among in-patients (53/506; 10.4%) compared to out-patients (182/4,074; 4.4%); p<0.05.

Old age (older than 60 years) represented a significant risk for having an ESBL-producing pathogen. Urine was the major source of ESBL isolates in in-patients (46.1%) and out-patients (74.4%).

The proportion of urinary E. coli isolates which were ESBL producers was significantly higher among in-patients (53/506; 10.4%) compared to out-patients (182/4,074; 4.4%); p<0.05.

Among in-patients, 60% of the ESBL associated infections were nosocomial. All were sensitive to imipenem but high levels of resistance to gentamicin, amikacin, amoxicillin-clavulanic acid and ciprofloxacin was shown.

CONCLUSION: The findings document evidence of the spread of multiresistant ESBL-producers into the community. This has significant implications for patient management, and indicates the need for increased surveillance and molecular characterization of these isolates.

http://www.ncbi.nlm.nih.gov/pubmed/19759493

 

[Gert van der Hoek]

Re: Community-acquired multiresistant bacteria - A potential pandemic ?

Int J Antimicrob Agents. 2009 Dec;34(6):544-9. Epub 2009 Sep 11.

Prevalence and types of extended-spectrum beta-lactamases among urinary Escherichia coli and Klebsiella spp. in New Zealand.


Abstract

The aims of this survey were (i) to determine the prevalence of extended-spectrum beta-lactamases (ESBLs) among urinary Escherichia coli and Klebsiella spp. in New Zealand (NZ), (ii) to identify the relative prevalence of ESBL types and (iii) to investigate clonality among ESBL-producing E. coli and Klebsiella spp.

During a 4-week period in 2006, 86% of NZ hospital and community diagnostic microbiology laboratories participated in the survey and referred isolates to the national reference laboratory. A total of 86 ESBL-producing isolates were identified, comprising 55 E. coli and 31 Klebsiella spp. (all Klebsiella pneumoniae), equating to prevalence rates of 0.7% and 4.2%, respectively.

The majority of the ESBL-producing E. coli (80.0%) and K. pneumoniae (58.6%) were reported to be from community-acquired urinary tract infections. CTX-M-15 and CTX-M-14 accounted for 75.9% and 13.3%, respectively, of the ESBL types identified.

A novel ESBL, designated CTX-M-68, was identified. Most CTX-M-15-producing isolates were multiresistant to three or more antibiotic classes. Pulsed-field gel electrophoresis typing identified a wide diversity of strains among the ESBL-producing E. coli, whereas the K. pneumoniae were more clonal.

The results of this survey show that the prevalence of ESBLs has increased in recent years in NZ, that CTX-M ESBLs are almost wholly dominant and that ESBL-producing organisms are already established as community-acquired pathogens.

http://www.ncbi.nlm.nih.gov/pubmed/19748232

 

[Gert van der Hoek]

Re: Community-acquired multiresistant bacteria - A potential pandemic ?

Med Mal Infect. 2011 Jan 5. [Epub ahead of print]

[Community-acquired methicillin-resistant Staphylococcus aureus (MRSA) infections.]

Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) has long remained the typical exclusively nosocomial pathogen, allowing using betalactam agents as first line presumptive treatment for severe community-associated infections in which MRSA was not taken into account.

The situation dramatically changed with the simultaneous emergence of several strains of community-acquired MRSA in Australia, Europe and in North America.

Although these clones clearly emerged from independent ancestors, they present almost invariably with two remarkable features, rarely found in other MRSA clones: (i) methicillin-resistance genes are harboured on a small size staphylococcal cassette chromosome (SCCmec type IV); (ii) they are all transfected by a phage carrying Panton-Valentine leukocidin (PVL) genes.

Since the early 2000, a specific clonal group, USA300, spread spectacularly all over North America.

A great number of publications documented (i) the unprecedented success of its dissemination in many settings; (ii) its virulence, illustrated by the description of invasive diseases not encountered thus far with traditional clones of hospital-associated MRSA (e.g. necrotizing pneumonia in immunocompetent patients).

In Europe, where community-acquired MRSA isolates mainly belong to the ST80 clonal group, its incidence has remained low, thus far. However, cautious surveillance and prompt responses are required if we are to avoid the public health scourge created by the emergence of community-associated MRSA in North America.

http://www.ncbi.nlm.nih.gov/pubmed/21215538

 

[Gert van der Hoek]

Re: Community-acquired multiresistant bacteria - A potential pandemic ?

Kathmandu Univ Med J (KUMJ). 2010 Jan-Mar;8(29):40-4.

Multiple drug resistance in bacterial isolates from liquid wastes generated in central hospitals of Nepal.

Abstract

BACKGROUND: Healthcare liquid wastes are the reservoirs of harmful infectious agents such as the pathogens and multiple drug resistant microorganisms. Potential infectious risks include the spread of infectious diseases and microbial resistance from health-care establishments into the environment and thereby posing risks of getting infections and antibiotic resistance in the communities.

OBJECTIVES: The objectives of this study were to assess the bacterial load of healthcare liquid waste generated in central hospitals and to explore the antimicrobial resistance pattern of these bacterial isolates.

MATERIALS AND METHODS: A descriptive study was carried out in 10 conveniently selected central hospitals of Nepal during the period of May to December 2008. Effluent specimens from each hospital were subjected to total viable count studies by spread plate method in nutrient agar plate and incubated for 24 hours at 37 °C using standard laboratory protocol. Similarly, all the specimens were cultured in Mac Conkey Agar media supplemented with 30 μg/ml of Chloramphenicol and 20 μg/ml of Gentamycin for the enumeration of multiple drug resistant (MDR) bacteria, which were further subjected to in-vitro antibiotic susceptibility test by modified Kirby Bauer disc diffusion technique for resistance patterns.

RESULTS: Total viable counts of hospital effluents significantly exceeded the standard heterotrophic plate count (p=0.000). Similarly, the numbers of multiple drug resistant bacteria were alarmingly high in three (more than 30% in 2 and 50% in 1) hospitals of this study. Drug resistant hospital effluent isolates showed simultaneous resistance for most of the antibiotics including Penicillin, Cephalosporin, Cotrimoxazole, Gentamycin and Quinolones.

CONCLUSION: Healthcare liquid wastes were laden with MDR bacteria and seemed to pose a huge public health threat in the transfer of such resistance to the bacterial pathogens causing community acquired infections, thereby limiting our antibiotic pool.

http://www.ncbi.nlm.nih.gov/pubmed/21209506

 

[Gert van der Hoek]

Re: Community-acquired multiresistant bacteria - A potential pandemic ?

J Am Acad Nurse Pract. 2011 Jan;23(1):23-32. doi: 10.1111/j.1745-7599.2010.00571.x. Epub 2010 Nov 5.

A literature review on community-acquired methicillin-resistant Staphylococcus aureus in the United States: clinical information for primary care nurse practitioners.

Abstract

PURPOSE: To analyze the state of the science of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) in the United States to support the integration of current knowledge for primary care nurse practitioners' (PCNP) practice.

DATA SOURCES: Published research limited to U.S. studies in MEDLINE, CINAHL, and Cochrane Review from 1950 to the week of September 4, 2008. Investigations were identified through electronic search engines and databases. Manual searches were done of hard copy references in journal articles. Citations and reference lists for English language research studies of CA-MRSA in the United States were reviewed to identify additional research that fit evaluation criteria for this analysis.

CONCLUSIONS: Until the late 1990s, healthcare-associated MRSA (HA-MRSA) was the predominant cause of serious infections. Recently, CA-MRSA has caused infections in previously healthy nonhospitalized people. Major demographic and epidemiological differences exist between the two types of resistant bacteria; the emergence of CA-MRSA suggests new implications for primary care.

IMPLICATIONS FOR PRACTICE: PCNPs will undoubtedly treat MRSA infections and need a comprehensive understanding of the pathogenicity, diagnosis, and management of CA-MRSA to ensure expedient and appropriate treatment. This will help to prevent invasive disease as a result of improperly treated infections.

http://www.ncbi.nlm.nih.gov/pubmed/21208331

 

[Gert van der Hoek]

Re: Community-acquired multiresistant bacteria - A potential pandemic ?

BMC Pediatr. 2010; 10: 100.
Published online 2010 December 29. doi: 10.1186/1471-2431-10-100.

Nasal Carriage and Antimicrobial Susceptibility of Staphylococcus aureus in healthy preschool children in Ujjain, India


Abstract

Background
There is increasing evidence that community acquired S. aureus infections are spreading among healthy children. Nasal colonization with S. aureus plays pivotal role in the increasing prevalence of resistant community acquired S. aureus infections worldwide. A regular surveillance system is important in ensuring quality of patient care. The aim of the study was to assess the prevalence of and the factors associated with nasal carriage of S. aureus and its antibiotic sensitivity pattern among healthy children in Ujjain, India.

Methods
A prospective study was done in paediatric outpatient clinics of R.D. Gardi medical college Ujjain, India. Healthy children from 1 month to 59 months of age were included. Information on previously known risk factors for nasal colonization was collected using a pre-tested questionnaire. Swabs from anterior nares were collected and transported in Amies transport media with charcoal and cultured on 5% sheep blood agar. Antibiotic sensitivity tests were performed using Kirby Bauer's disc diffusion method according to performance standards of Clinical and Laboratory Standard Institute guidelines.

Results
Of the 1,562 children from 1-month up-to five years of age included in the study 98 children tested positive for nasal carriage of S. aureus. The prevalence of nasal carriage of S. aureus was 6.3% (95% CI 5.1-7.5) out of which 16.3% (95% CI 8.9-23.8) were methicillin-resistant S. aureus (MRSA). The factors associated with nasal carriage were "child attending preschool" (OR 4.26, 95% CI 2.25-8.03; P = 0.007) or "school" (OR 3.02, 95% CI 1.27-7.18; P < 0.001) and "family size more than 10 members" (OR 2.76 95% CI 1.06-7.15; P = 0.03). The sensitivity pattern of isolated S. aureus showed resistance to commonly used oral antibiotics while resistance to glycopeptides was not noted.

Conclusions
We found a relatively low rate of nasal carriage of S. aureus in children below five years when compared to children of older age groups in India. Yet, prevalence of MRSA was relatively high.

Carrier rates of S. aureus and MRSA reported in different studies

link to table

Full article


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[Gert van der Hoek]

Re: Community-acquired multiresistant bacteria - A potential pandemic ?

Some snips of the article

Full article available online


Yale J Biol Med. 2010 December; 83(4): 223–233.
Published online 2010 December.

Methicillin-Resistant Staphylococcus Aureus: A Pervasive Pathogen Highlights the Need for New Antimicrobial Development

THE SPREAD OF MRSA
MRSA is spreading and causing disease at a rapid rate. Outbreaks have frequently been reported in neonatal and surgical intensive care units, burn units, inpatient wards, and operating rooms [34]. The patient-to-patient nosocomial transmission responsible for such outbreaks predominantly occurs through the hands of healthcare workers [35]. The proportion of MRSA-related S. aureus infections in hospital intensive care units has increased steadily from 2 percent in 1974 to 22 percent in 1995 and 64 percent in 2004 [36]. In 2005, 58 percent (278,000) of hospitalizations that included a diagnosis of S. aureus were caused by MRSA (including those admitted to the hospital for community-acquired infections) [37]. According to a 2005 estimate, nearly 19,000 deaths were caused by MRSA [38]. Moreover, MRSA is now considered one of the leading causes of death by any single infectious pathogen [39]. MRSA, therefore, has expeditiously become a significant health burden to society.

Fortunately, major hospital efforts and campaigns to reduce hospital-acquired infections have helped diminish the incidence of MRSA-related illness [40]. These efforts include: 1) reduction in antibiotic use; 2) healthcare worker education; 3) hand washing protocols and monitoring; 4) surveillance cultures; and 5) isolation of patients colonized with MRSA or perceived as a high risk for infection [41]. Active surveillance cultures and isolation protocols remain controversial as some studies have demonstrated the lack of utility in employing widespread screening efforts outside of the intensive care units [41].

Hospital-based movements to reduce the incidence of MRSA have undoubtedly demonstrated success. Between 2001 and 2007, MRSA central line-associated bloodstream infections within intensive care units have decreased by nearly 50 percent [42]. Similarly, a separate study that investigated hospitalized patients between 2005 and 2008 demonstrated a 34 percent reduction in the incidence of MRSA-related bloodstream infections [40]. Continued efforts must be exercised to prevent the spread of MRSA in the hospital setting. New strategies may include attempts to minimize the length of hospital stay and improved surveillance techniques, as well as more strict hand hygiene regulations [35].


FROM THE HOSPITAL TO THE COMMUNITY
While MRSA was once just a hospital-acquired infection observed in immunocompromised hosts, the rapid and persistent emergence of community-associated MRSA (CA-MRSA) has caused considerable concern.

Illustrative of its means to quickly disseminate through populations is its pervasive international presence and its ability to spread between continents [39,43]. The medical community recognized the first cases of CA-MRSA in the 1990s, first in remote Western Australia [44] and then with a group of otherwise healthy children in the Midwestern United States [45].

None of the affected individuals had contact with the healthcare setting or exhibited any identified risk factors prior to infection. The ability of CA-MRSA to cause disease in immunocompetent healthy hosts suggests that CA-MRSA harbors novel mechanisms of virulence [39].

Genetic analyses of CA-MRSA isolates support this assertion, as several isolates harbor a unique mec element as well as express the Panton-Valentine leukocidin (PVL), a factor linked to severe skin infections in the community [3,46]. Given that nearly 90 percent of CA-MRSA cases are skin and soft tissue infections, 90 percent of which are abscesses or cellulitis [39], it is likely that PVL plays a significant role in the pathogenesis of CA-MRSA. Future concern and attention is certainly warranted. The presence of severe community-acquired infections such as purpura fulminans, myositis, osteomyolitis, and necrotizing fasciitis suggests the potential for increased virulence [39].

The emergence of CA-MRSA as a growing threat has posed new preventive and therapeutic challenges. Akin to hospital-acquired MRSA, the community variant demonstrates extensive resistance to β-lactam antibiotics.

Currently, little clinical evidence exists regarding the efficacy of alternative agents. Thus, most non-invasive CA-MRSA skin infections are not treated with antibiotics. Instead, abscesses are simply drained [39]. If antibiotics are indicated as the result of more significant signs of infection, clindamycin, tetracyclines (including doxycyline), trimethoprim-sulfamethoxazole, and linezolid are the drugs of choice [47]. More severe cases of CA-MRSA are treated with parenteral vancomycin, daptomycin, teicoplanin, or linezolid [48].

THE ANTIBIOTIC PIPELINE
The Centers for Disease Control (CDC) estimates that roughly two million people in the United States will develop bacterial infections while in the hospital and that nearly 90,000 will die from associated complications.

Close to 70 percent of the bacteria responsible for these infections will be resistant to at least one commonly used antibiotic.

In recent decades, antibiotic resistant organisms have spread at alarming rates, causing the Institute of Medicine, CDC, National Institutes of Health, and the Food and Drug Administration (FDA) to caution that drug-resistant organisms pose a serious public health concern [49].

Given the rapid spread of drug-resistant bacteria, one might suspect that the pharmaceutical and biotechnology industries would be countering with an equally impressive course of antimicrobial development. However, the spread of drug-resistant organisms has largely outpaced antibiotic research and development. In fact, in comparing the periods of 1998 to 2002 and 1983 to 1987, FDA approval of new antibiotics decreased 56 percent, with no new antibacterial agents approved in 2002. A startling downward trend emerges when examining the number of new systemic antibiotics approved by the FDA over the last 25 years [50] .

CONCLUSION AND OUTLOOK
Without a doubt, the medical community is now astutely aware of the global burden of disease imposed by drug-resistant S. aureus infections. The ubiquitous knowledge of MRSA in communities is evident by its common use as a new household term. The consequences of the MRSA pandemic are profound and worrisome. MRSA itself is only a symptom of a broader phenomenon, a harbinger of a growing pool of resistant pathogens found both in hospitals and in the community.

While researchers, both academic and pharmaceutical, are working to develop therapeutic responses and have already have made significant advances, considerable work remains. The continued emergence of resistant strains of bacteria such as MRSA demands an urgent response. An efficient, comprehensive, multidisciplinary search for new antibiotics must commence to prepare us to squelch strains of resistant pathogens as they inevitably strike.

 

[Gert van der Hoek]

Re: Community-acquired multiresistant bacteria - A potential pandemic ?

Postgrad Med. 2010 Nov;122(6):16-23.

Methicillin-resistant Staphylococcus aureus: a community health threat.

Abstract

Methicillin-resistant Staphylococcus aureus (MRSA), one of the most common causes of infections, has been traditionally recognized as a nosocomial pathogen. However, in recent years, its epidemiology has radically changed, being now observed even more frequently in the community, and accounting for > 50% of staphylococcal infections in the US outpatient setting.

Community-acquired (CA)-MRSA strains typically cause infections among otherwise healthy individuals, with risk factors differing from those of nosocomial MRSA. The clinical manifestations may range from a furuncle to life-threatening infections, such as necrotizing fasciitis and pneumonia. The antibiotic treatment of these infections may also differ because CA-MRSA strains often retain susceptibility to antimicrobials other than glycopeptides and newer agents.

Moreover, the production of toxins, such as the Panton-Valentine leukocidin (PVL), should influence the antibiotic choice because in these cases the use of a combination therapy with antimicrobial agents able to decrease toxin production is suggested.

There are still many unanswered key questions regarding the epidemiology, prevention, and treatment of CA-MRSA infections. This article reviews current knowledge of CA-MRSA.

http://www.ncbi.nlm.nih.gov/pubmed/21084777

 

[Laidback Al]

Re: Community-acquired multiresistant bacteria - A potential pandemic ?

Thanks for pulling together this thread, Dutchy.