Molecular subtyping of Staphylococcus aureus from an outbreak associated with a food handler

Carriage of Antibiotic Resistant Bacteria and Associated Factors Among Food Handlers in Tamale Metropolis, Ghana: Implications for Food Safety

Background

Bacteria pathogens constitute a significant proportion of diarrhoea-causing food contaminants. Transmission of antibiotic resistant foodborne pathogens to humans is a major threat to food safety, especially in developing countries where quality hygiene and sanitation facilities are lacking. Factors related to antibiotic use, sanitation and hand hygiene have been associated with the spread of infectious diseases as well as antibiotic resistant bacteria. Proper food handling ensures that food is not contaminated with potential pathogenic bacteria. This study assessed the carriage of antibiotic resistant bacteria and associated factors.

Methods

A cross-sectional study was conducted among food handlers who sell ready to eat food in the Tamale metropolis of the Northern Region of Ghana. Food vending stations with huge customer base were randomly selected and the food handlers recruited using written informed consent. Structured questionnaires were used to collect participants sociodemographic details and information on sanitation, hand hygiene practice and antibiotic use. Sterile cotton swabs soaked in phosphate buffered saline was used to swab the palms of participating food handlers for bacteria isolation. All identified bacteria were tested for susceptibility to 12 antibiotics.

Results

In all, 406 food handlers participated in this study, the mean (SD) age was 26.5 (2.64) years. Bacteria isolated were predominantly Staphylococci 60 (14.8%) and Escherichia coli 54 (13.3%). All the isolates were resistant to at least one antibiotic tested. The isolates showed high resistance to broad-spectrum antibiotics such as ampicillin (40.0%-75.0%), tetracycline (40.0%-80.0%), amoxiclav (20.0%-80.0%) and chloramphenicol (7.7%-50.0%). Logistic regression model revealed that the carriage of antibiotic resistant bacteria by food handlers was significantly associated with age, educational level, years on the job, training in food preparation, hygiene practice, water source, type of toilet facility used and antibiotic use.

Conclusion

Street food handlers could be potential sources of food-borne transmission of antibiotic resistant bacteria.

Microbial Quality and Safety of Sushi Prepared with Gloved or Bare Hands: Food Handlers' Impact on Retail Food Hygiene and Safety

Food handlers play an important role in retail food hygiene and safety. This study was conducted to better understand the impact of food handlers on the microbiological quality and safety of sushi and ingredients handled by gloved and bare hands. At retail premises, food handlers were asked to prepare a batch of sushi with raw fish followed by a batch of sushi with cooked ingredients. Food (sushi and ready-to-eat ingredients), hand, and glove samples were collected for analysis of overall microorganisms (standard plate counts) and targeted foodborne bacteria: Staphylococcus aureus, Bacillus cereus, Escherichia coli, Salmonella, and Listeria monocytogenes. Results suggested that cross-contamination was more prevalent at premises where bare hands were used to prepare sushi. When bare hands were used, significantly higher standard plate counts were obtained from samples of cooked rice (2.3 to 4.9 log CFU/g) and sushi (2.8 to 6.9 log CFU/g) and the prevalence of S. aureus in samples was higher on food (21.7%, 28 of 129 samples) and hands (30%, 18 of 60 samples) ( P < 0.05). Glove changing in combination with hand washing minimized cross-contamination during sushi preparation as indicated by the lower prevalence of S. aureus (0%, 0 of 28 samples) and total targeted foodborne bacteria (3.6%, 1 of 28 samples) on the gloves of food handlers who changed gloves and washed their hands compared with those handlers who did not don new gloves. Repeated use of dishcloths could be a cause of cross-contamination, and the prevalence of total targeted foodborne bacteria was significantly higher on hands dried with dishcloths (64.7%, 11 of 17 samples) than on hands dried with paper towels (12.5%, 1 of 8 samples) ( P < 0.05). The prevalences of B. cereus, L. monocytogenes, and Salmonella in the 356 food samples were 5.1% (18 samples), 0.8% (3 samples), and 0%, respectively. Improvements to hand washing, hand drying, and glove changing practices are needed to lower the occurrence of cross-contamination during sushi preparation.

Staphylococcus aureus and Methicillin-Resistant Staphylococcus aureus in Workers in the Food Industry

Staphylococcus aureus is part of the common flora on the skin and mucous membranes of mammals and approximately 20–30% of humans are persistently colonized, mainly by mostly susceptible human-adapted isolates. In contrast, colonization with methicillin-resistant S. aureus is rare (approximately 1%), predominantly transient and associated with prior contact to the health care system. Additionally, in recent years livestock-associated S. aureus clones contributed to colonization in humans, especially in those working in close contact to farm animals. A considerable percentage of colonizing S. aureus isolates is equipped with enterotoxin genes. Humans carrying enterotoxigenic isolates represent a contamination source when handling food, thus generating a continuous risk of S. aureus food intoxication. Molecular characterization of isolates colonizing humans and obtained from food, respectively, enables the tracing of food-related outbreaks back to the source of food intoxication. We will summarize current knowledge about the S. aureus population colonizing humans, including those in close contact to animals and food, respectively. Additionally, we will review data on the molecular characterization of S. aureus isolates related to staphylococcal foodborne disease and the elucidation of staphylococcal foodborne outbreaks. Staphylococcal food poisoning is a common foodborne disease, mediated by the ingestion of enterotoxins produced by enterotoxigenic strains of S. aureus. For several outbreaks of foodborne S. aureus disease, colonized personnel could be identified as the source of food contamination. However, because of the widespread occurrence of enterotoxigenic strains as human colonizers and the often transient nature of colonization, the source of contamination cannot always be identified unambiguously. Therefore, compliance with hygiene measures is the most important requirement to prevent food contamination by both human colonization and environmental S. aureus reservoirs.

Staphylococcus aureus Entrance into the Dairy Chain: Tracking S. aureus from Dairy Cow to Cheese

Staphylococcus aureus is one of the most important contagious mastitis pathogens in dairy cattle. Due to its zoonotic potential, control of S. aureus is not only of great economic importance in the dairy industry but also a significant public health concern. The aim of this study was to decipher the potential of bovine udder associated S. aureus as reservoir for S. aureus contamination in dairy production and processing. From 18 farms, delivering their milk to an alpine dairy plant for the production of smeared semi-hard and hard cheese. one thousand hundred seventy six one thousand hundred seventy six quarter milk (QM) samples of all cows in lactation (n = 294) and representative samples form bulk tank milk (BTM) of all farms were surveyed for coagulase positive (CPS) and coagulase negative Staphylococci (CNS). Furthermore, samples from different steps of the cheese manufacturing process were tested for CPS and CNS. As revealed by chemometric-assisted FTIR spectroscopy and molecular subtyping (spa typing and multi locus sequence typing), dairy cattle represent indeed an important, yet underreported, entrance point of S. aureus into the dairy chain. Our data clearly show that certain S. aureus subtypes are present in primary production as well as in the cheese processing at the dairy plant. However, although a considerable diversity of S. aureus subtypes was observed in QM and BTM at the farms, only certain S. aureus subtypes were able to enter and persist in the cheese manufacturing at the dairy plant and could be isolated from cheese until day 14 of ripening. Farm strains belonging to the FTIR cluster B1 and B3, which show genetic characteristics (t2953, ST8, enterotoxin profile: sea/sed/sej) of the recently described S. aureus genotype B, most successfully contaminated the cheese production at the dairy plant. Thus, our study fosters the hypothesis that genotype B S. aureus represent a specific challenge in control of S. aureus in the dairy chain that requires effective clearance strategies and hygienic measures already in primary production to avoid a potential transfer of enterotoxic strains or enterotoxins into the dairy processing and the final retail product.

Investigation of a staphylococcal food poisoning outbreak combining case-control, traditional typing and whole genome sequencing methods, Luxembourg, June 2014

In June 2014, a staphylococcal food poisoning outbreak occurred at an international equine sports event in Luxembourg requiring the hospitalisation of 31 persons. We conducted a microbiological investigation of patients and buffet items, a case-control study and a carriage study of catering staff. Isolates of Staphylococcus aureus from patients, food and catering staff were characterised and compared using traditional typing methods and whole genome sequencing. Genotypically identical strains (sequence type ST8, spa-type t024, MLVA-type 4698, enterotoxin A FRI100) were isolated in 10 patients, shiitake mushrooms, cured ham, and in three members of staff. The case-control study strongly suggested pasta salad with pesto as the vehicle of infection (p<0.001), but this food item could not be tested, because there were no leftovers. Additional enterotoxigenic strains genetically unrelated to the outbreak strain were found in four members of staff. Non-enterotoxigenic strains with livestock-associated sequence type ST398 were isolated from three food items and two members of staff. The main cause of the outbreak is likely to have been not maintaining the cold chain after food preparation. Whole genome sequencing resulted in phylogenetic clustering which concurred with traditional typing while simultaneously characterising virulence and resistance traits.

Staphylococcus aureus strains associated with food poisoning outbreaks in France: comparison of different molecular typing methods, including MLVA

Staphylococcal food poisoning outbreaks (SFPOs) are frequently reported in France. However, most of them remain unconfirmed, highlighting a need for a better characterization of isolated strains. Here we analyzed the genetic diversity of 112 Staphylococcus aureus strains isolated from 76 distinct SFPOs that occurred in France over the last 30 years. We used a recently developed multiple-locus variable-number tandem-repeat analysis (MLVA) protocol and compared this method with pulsed field gel electrophoresis (PFGE), spa-typing and carriage of genes (se genes) coding for 11 staphylococcal enterotoxins (i.e., SEA, SEB, SEC, SED, SEE, SEG, SEH, SEI, SEJ, SEP, SER). The strains known to have an epidemiological association with one another had identical MLVA types, PFGE profiles, spa-types or se gene carriage. MLVA, PFGE and spa-typing divided 103 epidemiologically unrelated strains into 84, 80, and 50 types respectively demonstrating the high genetic diversity of S. aureus strains involved in SFPOs. Each MLVA type shared by more than one strain corresponded to a single spa-type except for one MLVA type represented by four strains that showed two different-but closely related-spa-types. The 87 enterotoxigenic strains were distributed across 68 distinct MLVA types that correlated all with se gene carriage except for four MLVA types. The most frequent se gene detected was sea, followed by seg and sei and the most frequently associated se genes were sea-seh and sea-sed-sej-ser. The discriminatory ability of MLVA was similar to that of PFGE and higher than that of spa-typing. This MLVA protocol was found to be compatible with high throughput analysis, and was also faster and less labor-intensive than PFGE. MLVA holds promise as a suitable method for investigating SFPOs and tracking the source of contamination in food processing facilities in real time.

Sustainable reduction of nasal colonization and hand contamination with Staphylococcus aureus in food handlers, 2002-2011

A longitudinal study of nasal colonization and hand contamination of food handlers with Staphylococcus aureus commenced in 2002 prior to the outbreak of severe acute respiratory syndrome. In the follow-up in 2003 when hygiene measures were strictly implemented, significant reductions in carriage were observed. To investigate if this change was sustained, nasal and hand carriage rates were compared between the earlier studies and a further sampling in 2011. The initial nasal carriage rate was 35% and hand contamination 41·2%, decreasing to 23·5% and 11·6%, respectively in 2003 (P < 0·001). In 2011, nasal carriage was similar to 2003 (22·9%), while hand contamination dropped further to 3·7% (P < 0·001). Spa-typing revealed 39 types in 2002 and 42 in 2011. This study reveals that the marked reduction in colonization had been sustained. This may be attributed to reduced opportunities for spread due to enhanced hygiene and reinforces its importance for control of disease.

Staphylococcal poisoning foodborne outbreak: epidemiological investigation and strain genotyping

In June 2011, an outbreak of Staphylococcus aureus enterotoxin food poisoning gastroenteritis occurred in Turin, Italy, following a catered dinner party at a private home. Within a few hours, 26 of the 47 guests experienced gastrointestinal illness, and 9 were hospitalized. A retrospective cohort study using a standardized questionnaire was carried out, and the risk ratios for each food item were calculated. The analysis indicated consumption of seafood salad as the most probable cause of the outbreak (risk ratio = 11.72; 95 % confidence interval, 1.75 to 78.54). Biological samples were collected from four of the hospitalized guests (stool and vomit), nasal mucosa swabs from three food handlers employed with the caterer, and available food residuals. All stool and vomit samples tested positive for enterotoxigenic S. aureus. As residues of the seafood salad were no longer available for sampling, suspected contamination could not be verified. However, no other food was found contaminated by S. aureus or its enterotoxins. All isolates from the biological samples were characterized at the genomic level by means of two multiplex PCR protocols to determine the presence of genes encoding staphylococcal enterotoxins, pulsed-field gel electrophoresis and staphylococcal protein A gene (spa) typing to describe their genetic profiles. All the isolates presented genes encoding SEA and SEI; the pulsed-field gel electrophoresis genetic profiles revealed the same pulsotype in the microorganism isolated from the hospitalized guests as in one of the isolates from a food handler's nasal mucosa, and the spa typing analysis reported two closely related spa types (t701 and t267), implicating the food handler as the most likely outbreak source.

Limited value of routine spa typing: a cross-sectional study of methicillin-resistant Staphylococcus aureus-positive patients in an Austrian hospital

BACKGROUND

We investigated whether spa typing is useful for indicating the setting of methicillin-resistant Staphylococcus aureus (MRSA) acquisition (community or health care acquired), the clinical relevance (colonization or infection), the type of infection (invasive or noninvasive), and the clinical outcome.

METHODS

Between August 2006 and December 2009, 381 routinely diagnosed culture-confirmed MRSA-positive patients were included into a cross-sectional study at an 800-bed hospital.

RESULTS

Out of 159 patients with colonization, 27 (17%) acquired MRSA in the community (CA-MRSA) and 123 (77.4%) in health care settings (HA-MRSA), and, of the 222 patients with infections, 119 (53.6%) had HA-MRSA and 103 (46.4%) had CA-MRSA. The 10 most frequent spa types accounted for 68.2% of the 346 typed MRSA isolates: t190 (28.3%), t032 (16.5%), t041 (9.4%), t008 (8.4%), t001 (3.4%), t002 (2.9%), t044 (3.1%), t223 (2.1%), t015 (2.1%), t127 (1.3%).

CONCLUSION

Spa typing of routinely identified MRSA isolates is unsuitable to predict the likeliness of an infection, of an invasive infection, and the clinical outcome. Molecular criteria such as spa type or Panton-Valentine leukocidin positivity used for classifying MRSA as either belonging to a community or hospital clone are of limited value to indicate the setting, where the MRSA strain was actually acquired according to epidemiologic criteria.

Prevalence of Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) in food samples associated with foodborne illness in Alberta, Canada from 2007 to 2010

Consumption of foods containing Staphylococcus aureus can cause severe gastro-intestinal illness. Given the fact that over the past decade, Canada has seen increasing rates of methicillin-resistant S. aureus (MRSA) carriage and infection, the objective of this study was to investigate the impact of methicillin-susceptible S. aureus (MSSA) and MRSA on foodborne illness in Alberta, Canada. Between January 2007 and December 2010, there were 693 food samples associated with foodborne investigations submitted to the Alberta Provincial Laboratory for Public Health (ProvLab). These foods were screened for: Bacillus cereus, Clostridium perfringens, S. aureus, Aeromonas spp., Campylobacter spp., Escherichia coli O157:H7, Salmonella, Shigella spp., and Yersinia spp. S. aureus was identified in 10.5% (73/693) of samples, and of these, 59% (43/73) were co-contaminated with at least one other organism on the screening panel. The S. aureus positive samples included 29 meat, 20 prepared foods containing meat, 11 prepared foods not containing meat, 10 dairy, and three produce. Methicillin-resistance was not detected in any isolates tested. These findings indicate that the presence of S. aureus in food associated with foodborne investigations is a cause for concern, and although MRSA was not found, the potential for outbreaks exists, and ongoing surveillance should be sustained.

Staphylococcus aureus and its food poisoning toxins: characterization and outbreak investigation

Staphylococcal food poisoning (SFP) is one of the most common food-borne diseases and results from the ingestion of staphylococcal enterotoxins (SEs) preformed in food by enterotoxigenic strains of Staphylococcus aureus. To date, more than 20 SEs have been described: SEA to SElV. All of them have superantigenic activity whereas half of them have been proved to be emetic, representing a potential hazard for consumers. This review, divided into four parts, will focus on the following: (1) the worldwide story of SFP outbreaks, (2) the characteristics and behaviour of S. aureus in food environment, (3) the toxinogenic conditions and characteristics of SEs, and (4) SFP outbreaks including symptomatology, occurrence in the European Union and currently available methods used to characterize staphylococcal outbreaks.

Prerequisite programs at schools: diagnosis and economic evaluation

In this study, 20 Brazilian public schools have been assessed regarding good manufacturing practices and standard sanitation operating procedures implementation. We used a checklist comprised of 10 parts (facilities and installations, water supply, equipments and tools, pest control, waste management, personal hygiene, sanitation, storage, documentation, and training), making a total of 69 questions. The implementing modification cost to the found nonconformities was also determined so that it could work with technical data as a based decision-making prioritization. The average nonconformity percentage at schools concerning to prerequisite program was 36%, from which 66% of them own inadequate installations, 65% waste management, 44% regarding documentation, and 35% water supply and sanitation. The initial estimated cost for changing has been U.S.$24,438 and monthly investments of 1.55% on the currently needed invested values. This would result in U.S.$0.015 increase on each served meal cost over the investment replacement within a year. Thus, we have concluded that such modifications are economically feasible and will be considered on technical requirements when prerequisite program implementation priorities are established.

Outbreaks where food workers have been implicated in the spread of foodborne disease. Part 5. Sources of contamination and pathogen excretion from infected persons

In this article, the fifth in a series reviewing the role of food workers in foodborne outbreaks, background information on the routes of infection for food workers is considered. Contamination most frequently occurs via the fecal-oral route, when pathogens are present in the feces of ill, convalescent, or otherwise colonized persons. It is difficult for managers of food operations to identify food workers who may be excreting pathogens, even when these workers report their illnesses, because workers can shed pathogens during the prodrome phase of illness or can be long-term excretors or asymptomatic carriers. Some convalescing individuals excreted Salmonella for 102 days. Exclusion policies based on stool testing have been evaluated but currently are not considered effective for reducing the risk of enteric disease. A worker may exhibit obvious signs of illness, such as vomiting, but even if the ill worker immediately leaves the work environment, residual vomitus can contaminate food, contact surfaces, and fellow workers unless the clean-up process is meticulous. Skin infections and nasopharyngeal or oropharyngeal staphylococcal or streptococcal secretions also have been linked frequently to worker-associated outbreaks. Dermatitis, rashes, and painful hand lesions may cause workers to reduce or avoid hand washing. Regardless of the origin of the contamination, pathogens are most likely to be transmitted through the hands touching a variety of surfaces, highlighting the need for effective hand hygiene and the use of barriers throughout the work shift.

Application of molecular techniques in the study of Staphylococcus aureus clonal evolution - A Review

Staphylococcus aureus is an important agent of healthcare-associated and community-acquired infections. A major characteristic of this microorganism is the ability to develop resistance to antimicrobial agents. Several molecular techniques have been applied for the characterization of S. aureus in epidemiological studies. In the present review, we discuss the application of molecular techniques for typing S. aureus strains and describe the nomenclature and evolution of epidemic clones of this important pathogen.

Relationships between toxin gene content and genetic background in nasal carried isolates of Staphylococcus aureus from Asturias, Spain

Staphylococcus aureus recovered from nasal carriers, producers and non-producers (43 isolates each) of classical pyrogenic toxin superantigens (PTSAgs), were screened for 17 additional PTSAg-genes by PCR. Percentages of 88.4 and 65.1 were positive for some new enterotoxin-gene, and 76.7 and 55.8 for enterotoxin-gene-clusters (egc-like), respectively. The 86 isolates belonged to 17 toxin-genotypes (all eta-, etb-, etd-, see- and sep-negative), and generated 40 SmaI-genomic profiles that in a dendrogram of similarity (S0.7) clustered into nine lineages and 11 non-clustered branches. Correlations between classical PTSAgs and SmaI-lineages were established and egc-like groupings appeared dispersed in six lineages.

Enterotoxins and toxic shock syndrome toxin in Staphylococcus aureus recovered from human nasal carriers and manually handled foods: epidemiological and genetic findings

A set of 269 Staphylococcus aureus isolates recovered from nasal carriers and manually handled foods in a region of Spain was analyzed for pyrogenic toxin production and toxin genes. Fifty-seven isolates producing at least one of four enterotoxins (SEA, SEB, SEC, SED), 10 isolates producing only toxic shock syndrome toxin (TSST-1), and 10 isolates producing both toxin types were found. The 77 toxigenic isolates were discriminated into 36 SmaI genomic and 13 EcoRI plasmid profiles. A strong relationship between toxin profiles with both SmaI genomic and EcoRI plasmid profiles was revealed. SmaI genomic profiles showing six or less mismatching fragments and similarity coefficient > or =0.7 were included in a lineage. Eight lineages were differentiated; six of them grouped both human and food isolates and two of these also included outbreak-implicated isolates. Two lineages, represented by TSST-SEA and TSST-1, on the one hand, and SEC and SEC-SED isolates, on the other hand, were the most frequent, but only the second was outbreak-related. When SmaI genomic and EcoRI plasmid profiles were hybridized with tst, sea, seb, and sec toxin probes, it was observed that each probe mapped on a different SmaI fragment from isolates falling into the same lineage. All of the probes only mapped on genomic fragments, but sed also mapped on three plasmid fragments. When sej and ser probes were included, they mapped together with sed on the chromosome and on the plasmids. Two plasmids (ca. 33 and 36 kb) carried the expected sed-sej-ser genes, while the other (ca. 53.5 kb) carried sed-sej and ser-like genes. The latter plasmid and the chromosomal location of sed-sej-ser are new findings from this study.

Genetic procedures for identification of enterotoxigenic strains of Staphylococcus aureus from three food poisoning outbreaks

Three food poisoning restaurant outbreaks due to Staphylococcus aureus, occurring during June-October 2002 in the Principality of Asturias (PA), Spain, provided the basis for investigating some aspects of the molecular epidemiology of this organism. The methods applied to identify strains and lineages included multiplex-polymerase chain reaction (PCR) to detect nine enterotoxin (se) genes, and three DNA fingerprinting procedures: pulsed-field gel electrophoresis (PFGE) with SmaI, randomly amplified polymorphic DNA (RAPD) with two selected primers, and plasmid restriction analysis with HindIII. Thirty-two isolates were differentiated into three non-se and 12 se strains, which were outbreak-specific, except for one that was represented in two of the outbreaks. In outbreak 1, the 16 food isolates analyzed had sec, seg and sei genes and generated a distinctive DNA fingerprint, being assigned to a single strain. This strain could be categorized as endemic in the PA and associated to manually handled dairy products and nasal carriers. In outbreak 2, the four food isolates analyzed fell into three strains, each one displaying a different se-gene profile (sea, sec and seg-seh-sei) and a distinctive DNA fingerprint. In outbreak 3, the five food isolates tested fell into four seg-sei strains generating identical RAPD but different PFGE and plasmid profiles, and one sea strain also collected from two nasal carriers. This last strain had also been found in manually handled vegetables in outbreak 2, and it belongs to a not very frequently found sea lineage in the PA. Multiplex-PCR to detect se genes together with the three applied DNA fingerprint typing procedures proved therefore to be useful tools in subclassifying S. aureus for epidemiological purposes.

Outbreak of infection with hepatitis A virus (HAV) associated with a foodhandler and confirmed by sequence analysis reveals a new HAV genotype IB variant

An outbreak of infection with hepatitis A virus associated with a foodhandler and involving 26 subjects occurred in Southern Italy. Sequence analysis of the VP3-VP1 and VP1-P2A junctions confirmed that the outbreak was due to a point source and allowed the identification of a new genotype IB variant. This report confirms the usefulness of sequence-based molecular fingerprinting during outbreaks.

Ribotyping and a study of transmission of Staphylococcus aureus collected from food preparation facilities

Food poisoning from Staphylococcus aureus is sometimes caused by improper handling of food items in food preparation facilities. Prevention of contamination by employees is particularly important in facilities where a significant amount of food preparation is performed by hand. Some experiments have been performed to describe bacterial cross-contamination in the food preparation process, but there have been few studies of cross-contamination in actual food preparation facilities. Aiming to shed light on the transmission of S. aureus in food preparation facilities, this study collected samples of 66 strains of this bacterium from the fingers of food preparation staff, foodstuffs, prepared foods, cooking utensils, and cooking equipment and typed them with the ribotyping method. S. aureus from the same ribogroup was detected on the hands of a study participant, a faucet, knife, frying pan, and a salad, indicating that bacteria found on the hands of the study participant was transmitted to cooking utensils and prepared foods. Transmission (from a faucet to a frying pan handle) of bacteria by another person, a third party, was also detected.