Laboratory transmission of enterobacteriaceae by the oriental cockroach, Blatta orientalis

Risk assessment of the mechanical spread of bacterial pathogens due to Lasius neglectus ants infesting a tertiary hospital

INTRODUCTION

Mechanical spread of microbial pathogens has been investigated in cockroaches, but less well in ants. Considerably less information is available for ants. An investigation into ant-borne mechanical pathogen transmission was triggered by an infestation of a tertiary care hospital with Lasius neglectus ants.

METHODS

The L. neglectus infestation of the orthopedic surgery, the ear-nose-throat clinics and the eye clinics as well as of outdoor areas was monitored and correlated with seasonal and weather influences. Microbial colonization on the ants' exoskeleton as well as in homogenates of complete insects and decolonization dynamics of artificially Staphylococcus aureus colonization on the exoskeleton was assessed.

RESULTS

In a low-level infestation setting, L. neglectus activity showed seasonal variations and was positively correlated with temperature (r=0.7515; P=0.0368) but not with precipitation (r=0.4699, P=0.2431). Colonization with environmental commensals dominated, while exoskeleton colonization with bacteria with potential etiological relevance for nosocomial infections was higher for ants from the inpatient setting (6%) than from outdoor areas (0%). Artificial colonization of the exoskeleton with S. aureus vanished to values statistically indistinguishable from baseline within 72 hours.

CONCLUSIONS

Low colonization rates with etiologically relevant bacteria and rapid spontaneous decolonization in case of contamination make ant-borne transmissions to patients unlikely.

Vector Potential of Blattella germanica (L.) (Dictyoptera: Blattidae) for Medically Important Bacteria at Food Handling Establishments in Jimma Town, Southwest Ethiopia

Cockroaches have been regarded as possible vectors of human enteropathogens. Their presence and crawl particularly in food handling establishments could be risky for human health. Therefore, this study was done to determine the vector potential of cockroach for medically important bacterial pathogens in restaurants and cafeterias. A cross-sectional study was conducted on cockroaches from restaurants and cafeterias in Jimma town from May to September 2014. Standard taxonomic keys and microbiological techniques were applied for species identification and isolation. Data was analyzed in SPSS version 16.0. All cockroaches trapped were the German cockroach, Blattella germanica (L.) (Dictyoptera: Blattidae). Escherichia coli was the most frequently isolated followed by Salmonella species (serogroups B, D, E, C₁, and NG), Bacillus cereus, and Shigella flexneri. Wide varieties of bacteria of medical relevance were also identified. Of which, Klebsiella spp. 49(40.8%), Bacillus spp., and Staphylococcus saprophyticus were predominant. Blattella germanica (L.) (Dictyoptera: Blattidae) could serve as a potential vector for the dissemination of foodborne pathogens such as Salmonella spp., Shigella flexneri, E. coli, S. aureus, and B. cereus and these bacteria could be a major threat to public health. Therefore, environmental sanitation and standard hygiene need to be applied in the food handling establishments in that locality.

The provision of food and catering services in hospital

The supply of food to patients and staff is the responsibility of hospital support services. This article considers the provision of catering services and the production of safe food in hospitals in the UK. The responsibilities of food handlers and the role of the infection control team, the environmental health officer and the occupational health staff are also described.

Bacterial load of cockroaches in relation to urban environment

Sanitation is an important problem in relation to the control of pests in urban environments. This investigation analysed the potential risk related to the presence of cockroaches and their capacity for disseminating bacteria in six different types of buildings: hospital nursing area and out-patient area, swimming-pool pool-side and toilet area, low-income flats and food-handling places. Fifty-six species of bacteria were identified from 157 samples, 14 of these have previously been reported as potentially pathogenic for man and vertebrates. Similarities were found between samples collected in (a) the hospital out-patient area and food-handling establishments and (b) the hospital nursing area and flats. Pool-sides possessed a poorer bacterial flora. There was a greater bacterial specific diversity in food-handling establishments, flats and swimming-bath toilet area. Enterobacter cloacae. Klebsiella pneumoniae and Klebsiella oxytoca were dominant species in flats and the hospital nursing area. Therefore, cockroaches can play a role in disseminating bacteria, which they can carry passively on their cuticle.

Cockroaches as carriers of bacteria in multi-family dwellings

The potential risk of bacterial dissemination due to the presence of cockroaches (Blattella germanica, Blattellidae) in low-income flats was investigated. Cockroaches can carry a great variety of bacterial species; we identified 30 different species from 52 different flats. Klebsiella oxycytoca, K. pneumoniae and Enterobacter cloacae were the most frequently found. Pathogenic and potentially pathogenic bacteria represented 54% of all the bacterial identifications. Bacteria were carried either on the cuticle or in the gut. Contamination through external contact is sufficient to insure bacterial diffusion. There was a very low level of overlap estimated by Pianka's index (a) between the bacterial flora of neighbouring blocks of flats, and (b) between bacterial flora of different flats in the same block.

Cockroaches (Blatta and Periplaneta species) as reservoirs of drug-resistant salmonellas

A total of 221 cockroaches (Blatta and Periplaneta spp.), collected in hospitals, houses, animal sheds, grocery stores and restaurants, in various parts of South Kanara District, a south-west coastal region of India, were studied bacteriologically for the presence of various salmonellas. Salmonellas were isolated from 4.1% of these cockroaches. Nine strains of salmonellas were recovered, belonging to five serotypes--Salmonella bovismorbificans, S. oslo, S. typhimurium, S. mbandaka and S. braenderup, the former two being the commonest serotypes. All salmonellas were resistant to one or other of 11 antibacterial drugs used in the susceptibility test. Isolation of salmonellas from cockroaches collected from the livestock premises and human dwellings suggested that they may act as significant reservoirs of salmonella in nature. Recovery of serotypes, phage types and R-types that were commonly isolated from humans and animals of this locality, suggested a transmission role for cockroaches. By harbouring potentially pathogenic, drug-resistant salmonellas, these wandering arthropods may pose dangerous infective hazards to humans and animals.

Microbial organisms carried by brown-banded cockroaches in relation to their spatial distribution in a hospital

A simultaneous study of cockroach (Supella supellectilium) distribution and of associated carried bacterial flora has been made in the main hospital in Rennes (France). Wild cockroaches carry a high number of bacterial species that can be related to the normal environmental flora and a contaminant flora acquired from particular environments. The diversity of carried bacterial species reveals a proximity factor between continguous floors of the building which leads us to suppose that cockroaches are able to forage from one floor to the other.